People often screw up the wiring. The most outstanding feature of this bike would have to be its final drive which consists of a solid drive shaft (with a torsion spring to dampen the engines vibration) that connects the transmission to a ring and pinion gear set in the rear hub. Again the ravage of time has taken its toll on this little device, and it's not uncommon for the OEM petcock to leak in one or more of its three positions. The bigger rear tire is heavier and your qt50 in stock form may not be able to spin it at the same rpms as the original tire. You can help Wikipedia by expanding it. These are usually the first things that are misplaced. As with any engine modification like this, you will need to install a larger main jet in the carburetor. I cleaned up the transfers on a Honda cylinder like the pic above. Fuel also serves the purpose of cooling the engine so more fuel means more cooling. Of course, youll need to change your main jet to a bigger one to compensate for the additional air (you need to keep your fuel/air ratio similar if you add more air, you need to add more fuel). Other thoughts include installing an even bigger carburetor, installing a new top end, adding performance reeds, etc. . That is just not going to work well. With all this in mind, what should you pay for a Yamaha qt50? A bigger cylinder head would also help with cooling. If your bike was owned by a kid in the past, your back tire may even be bald. The lesson of mopeds and nopeds is to find your next bottleneck and fix it. 2. Ive added a video on this modification here at the bottom of this page. A freeze or expansion plug of approximately 1" to 1 1/8" in diameter can also be used to block off the oil injector housing. The QT50 has a sealed beam headlight. 6. What should you pay for (or sell) a Honda Express? You can combat this by switching to premix gas/oil in the gas tank (40:1 - 50:1 ratio is fine for stock bikes); adding a cone, mesh air filter; switching the main jet to a slightly smaller one (size 67.5); or combination thereof. Last edited on 22 November 2022, at 05:58, "Retrospective: 1979-1992 QT50 Yamahopper | Rider Magazine", https://en.wikipedia.org/w/index.php?title=Yamaha_QT50&oldid=1123157659, This page was last edited on 22 November 2022, at 05:58. Several methods are outlined here at mopedarmy.com. Yamaha may have intended that the bike run rich to promote engine life. I'll make videos of each top speed run and post them here. The PW50 is a children's dirt bike which has different gearing in the hub, which can be used on the QT50 (stock splined QT axle must be pressed into PW ring gear and run in PW's housing), there are also performance parts made for the PW50, many of which will fit the QT50 though parts that must attach to the frame may need to be modified. 8. On a large ride, I was able to keep up with the Puch's and Carabela's. Im hoping an extra 25 psi helps out quite a bit. Buy yamaha qt50 online with fast delivery and free shipping. Makes me wonder how anyone could really go fast with a stock head. Half the package or less is plenty. A Q-tip cut in half and then placed in your drill is another handy tool for cleaning the seat. Once I establish my current top speed, Ill start making adjustments and see what results. Once kicked to life with the reverse-mounted, left-side kickstart lever, the key is turned to "run" and the engine is able to rev freely. After the main jet, dial in the jet needle. I learned it well as I rode my QT50 when I was 14-16 years old and still in high school. I have 0W-20, straight 30W synthetic, synthetic transmission fluid. Available at Brennys Motorcycle Clinic in Bettendorf, Ia. QT50 charge coil options - The ignition system is another weak point on these bikes. Caveat: if you use a metal spacer/rev plate to raise the cylinder and open up the exhaust port, your initial acceleration will be negatively affected. Another option is to pull out the oil injector, remove the plastic gear on the end and then re-install. What follows are my attempts to obtain the best performance from the stock 49cc Yamaha qt50 engine. Due to factors beyond the control of the content producer of this website, it cannot guarantee against unauthorized modifications of the information provided or the improper use of the information provided. Damn that was sweet! At the time it died out, it was still accelerating! No such rev limiter exists. Check and see if all the lights and horn work. Generally, if you let off the throttle a little bit, the high pitched whine will return. So you want your Honda Express to go faster. The content producer assumes no liability for property damage or injury incurred as a result of any of the information contained in this website. This headlight has a replaceable bulb and fits perfectly in the QT50's headlight ring. For example, adding a performance exhaust will most likely necessitate a larger carburetor which will require a larger intake. Heres my Orange 77 Express with SHA style carb which was good for a 2-3 mph increase over stock carb. Stock cylinder head is horrible on cooling. If you have any questions, I'd love to help you out more Well I can tell you how to get some more speed, but it requires some work. Ok, so I put a DR kit on the Orange Express. And Im happy to buy a non-runner because you often have to put as much into a running bike as a non-running bike. Jan 09, 2023 08:37PM. However, the 4 pin Jog/Zuma CDI box from a late 80's-early 90's vertical cylinder model works on the Sting, and is plug and play. The oil pump is reputed to add excessive amounts of two stroke oil to the fuel. 1979 Yamaha qt50 speed run - YouTube AboutPressCopyrightContact usCreatorsAdvertiseDevelopersTermsPrivacyPolicy & SafetyHow YouTube worksTest new features 2022 Google LLC The QT50 drive train was shared by the Tri-Zinger and PW50. The header on my stock exhaust is kind of beat up so Im running a double exhaust gasket to seal it up. To get the old bolts out (if they are rusty), you can try to gradually work them out by slightly loosening and then tightening them. 278-27114-00) and super glue it to the original stopper so that you have two stacked together. Now imagine what happens when you put these holes in the back of the airbox. The VM18 will require MLM's intake designed for the VM18. The rear brakes tend to be weak on this bike. In addition 60cc top ends are prevalent on ebay and amazon. Im currently running 10W-40 conventional oil and I think I notice some drag on cold days. Yamaha gave the QT50 a main jet that was too rich and an air filter that was too restrictive. Re: I got manuals for yall on the net for FREE. I treat all these as non-runners. Tire width goes to 3.15 inches and top speed goes to 32.71 mph. Ok, I changed the transmission oil to 5W-30 and lost 0.9 mph. Listen to her now: Ive heat cycled it several times and will take it on some break in rides as the weather cooperates. Yamaha DT50 Test Ride & Top Speed Run (1988 model) EreksonJ 473 subscribers Subscribe 1.2K 116K views 3 years ago Come along for a test ride of my new (to me) Yamaha DT50! With a fully open exhaust port expect gains of 3-4 mph. Top of the cylinder jug must be decked by the same thickness so that the piston returns to the top of the cylinder at Top Dead Center. Although unlikely that any significant difference exists, the straighter version contributed more to performance than the "S" shaped version. seat is beat up subtract $40; Im still breaking it in and have encountered and overcome several hurdles already. The qt's metal tank can become rusty over time and especially if stored with gas in the tank. As above, a cheap aftermarket 6 volt flasher is easily attained. One leads to the oil pump and one leads to the carburetor. Stock main jet size in the QT50 is a 70. I had cyclekeysonline make me a $10 key for it and it worked. Waiting on puch head to arrive. Adjust the oil injection pump; But no worries. Controlling the heat produced by a bigger top end and/or a performance exhaust is a common issue with QT50s. Truth is it is getting too much gas and dying as a result. Remove the charge coil and install on the QT50 stator. 2 stroke engines are designed to four stroke in certain situations. If it does not, your compression will suffer. Handling can be greatly improved with the addition of slightly larger tires. Ride, handling, braking and, to a small extent, top speed can be improved with them. Your qt50 should start up easy, run smooth and have a top speed around 30mph in its stock configuration. Reply. Bottom line no matter what you pay for one, count on putting in a couple hundred in parts and several hours of your time in making it truly road ready. Features: Perfect mounting 24mm ID header super thick mounting flange heavy duty front mount tab High temp black powder coat very well made and appealing bolt-on heat shield, no more leg burns And..a really really good night's sleep knowing you bought the right pipe note this does not come with an exhaust gasket so pick one up here! Want to post in this forum? Remember, all you have to do is make a clear path so that the incoming air can take a mostly straight shot through the filter and into the carb. They just need to make the cylinder "breathe" better at mid/high RPM. Many have had better luck with the slightly smaller 67.5 main jet. The engine needs more fuel going uphill because it is under a bigger load. Day 1 - 49cc engine is on my blue qt50. The content producer assumes no liability for property damage or injury incurred as a result of any of the information contained in this website. Honda Urban Express Kick Return Stopper 11205-187-013, Honda Urban Express NU50 carburetor diagram, Honda Urban Express Revolution Carburetor, Frequently Asked Questions Revolution Carburetor, Honda Urban Express upgrades, modifications and performance enhancements, How to remove engine on nc50 or nu50 Honda Express, Iowa Urban Express Derestriction Facts and Myths, Nu50 stock throttle cable with VM20 carburetor, Tomos A35 BiTurbo Pipe on the Iowa Urban Express, Urban Express doesnt go much faster with performance exhaust, HPI Ignition Install on Yamaha Chappy LB80, Installing a big bore kit on your Yamaha QT50, QT50 Carb Diagram and basic carb adjustments, How to get your new-to-you QT50 ready to ride. Ill up my main jet. So, in essence, it would be getting too little fuel. It has a 15.15 SHA clone carb and currently running a 75 main jet. Mine changes gears . Prices vary throughout the country. Take out the spark plug and shine a light into the cylinder and get an idea of the condition of the top of the piston. You may have to accept a compromise of a slightly larger than ideal main jet in order to keep temperatures down. Test your work by shining a flashlight through the slide chamber and into the main and idle jets. The immediate goal is to break 40 and then shoot for 45 mph. The content producer recommends safe practices when repairing, modifying, and/or performance enhancing mopeds, nopeds, small motorcycles and the like as well as working with power tools, hand tools, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this website. You will need to replace your main jet with a bigger main jet. A 67.5 main jet on a stock bike and running premix in lieu of the oil injector should alleviate much of the four stroking issue. Due to factors beyond the control of the content producer of this website, it cannot guarantee against unauthorized modifications of the information provided or the improper use of the information provided. Try a hotter spark plug; You need to get another Yamaha Center Stand Stopper (part no. You need one with the eyelet at the top and the clevis end at the bottom. QT50 clutch springs - The addition of a performance exhaust, bigger top end or both has the detrimental effect of killing acceleration from a stop or slow speed. 10. Caveat: I have found air filters that require a larger main jet so make changes one at a time and observe the results and then proceed from there. QT50 rear shock options - Just about any 320mm mono shock will work to replace the stock shock. However, this 5 wire box DOES NOT work for the Sting. This part is used to reduce the degree of performance for your motorcycle, for yamaha. Other cooling methods include running a thicker head gasket (or more than one head gasket) to reduce compression (you can also reduce compression by increasing cylinder head chamber size) and running a Jog cdi with a curve that allegedly retards timing at higher rpms. Performance modifications will only exaggerate current issues. 3. Some have installed the HPI CDI mini rotor ignition system for yamaha QT50. If it will do its top speed of 29-30 mph, youre in luck. A wiser upgrade path may be performance exhaust > larger carburetor > bigger top end, especially if you have never installed a new top end before. The Jog CDI has five wires as opposed to the QT50's four. Youll thank me later. It also leads to using a key other than the Yamahopper one. The QT50 and the Honda Express are similar in appearance. The next easiest thing that you can do is slap on an expansion chanber. I ordered a puch 40mm head. Motion Pro Rubber Sleeve (11-0045) 0 # mpn4565891373. Install a new and bigger rear tire. Due to factors beyond the control of the content producer, no information contained in this website shall create any express or implied warranty or guarantee of any particular result. Yamaha has tuned the engine to do this in that situation and it represents a compromise. Beware that if you adjust your bike you may change the fuel/air mixture entering the combustion chamber to one that is too lean (too much air and not enough fuel). Turn signals and mirrors are also casualties of past wrecks. If it doesnt pass all the tests above, subtract as follows: Very rusty gas tank requiring replacement $80-100 deduction; Needless to say I didn't do any calculations to figure out how much to actually take off the head. Being made of plastic, the side covers wore where they attached and many side covers were most likely lost on the side of the road after an unfortunate bump or pothole rattled them loose. Again, a performance exhaust will call for a larger main jet in the carburetor. Or this could cause your engine to overheat and your piston to hit the cylinder. I imagine the rear fender would have to go with this tire and would the tire fit on the rim? Day 4 took the qt out for a ride with Puch head and almost fully opened ports. Picture the maze that the incoming air had to follow just to get to the carb. Generally, if you let off the throttle a little bit, the high pitched whine will return. This cut down on the brake bill dramatically. The 50 in the name is derived from the 50cc engine displacement. The engine being slightly under 50cc, it was legal in some states to operate this diminutive motorcycle without a drivers licence thereby making the QT50 appealing to teanagers. Crankshaft bearing seal replacement on mj50, qt50 and pw50. Yamaha MJ50 Towny two-speed crankcase and right-side swingarm. Ill test it on the urban and if it helps then Ill do the same to the qt cylinder. The following is a guide of some sorts of what CAN and CANNOT be used while restoring this guy It CAN use the same Shock as the QT50 It CANNOT use the QT50 crank It CANNOT use the Chappy crank It CAN use the same CDI magneto as the QT50 The wheels are sturdy for being only 14" but abuse should be avoided. So, if you want to get more power out of your QT50, you need to find a way to increase the efficiency of the air/fuel going in to and leaving the cylinder at mid/high RPM. The QT50 does not have a governor or a rev limiter. We are back up and running. I thought over the next few weeks Id perform some experiments on my stock NC50 to see how fast I could get it to go without using any performance parts (I do have a K&N hi-flow air filter). MLM makes a performance exhaust for the QT50, the MLM Yamaha QT50 People's Sidebleed Pipe. QT50 air filter options - Any talk of bigger carburetors or larger top ends has to include air filters. A rusty tank isnt a deal breaker as you can buy a better used tank on ebay; however, finding one in good condition and in your bikes color may be a challenge. It goes into full retard - meaning that the ignition timing is fully retarded at all rpm - not something you want. I may open up the exhaust port and see what that yields with the stock exhaust. All this is necessary to avoid seizing your piston as the performance exhaust will have the effect of leaning out your fuel/air mixture. Re: RPM gauge for the Yamaha QT50. I go over some pretty simple cylinder modifications to get more speed.spacers - https://www.treatland.tv/SearchResults.asp?Search=honda+metal+spacer+basespac. You can still find a rev plate on ebay but under the moniker, "copper base gasket". So the caveat here is just because it runs and rides well doesnt mean you are home free. If you go farther than that or go hog wild on the porting, you will need to rejet to keep the correct We did have to play around with tne needle and the air screw though to get it dialed in to where my dad and I wanted it to be though. -DO NOT CONTACT ME. In addition the IRC NR 77 80/90 rear tire may work on the rear but you may have to lose the rear fender or use an aftermarket fender (Update - I've seen the IRC NR 77 80/90 successfully mounted on the rear with some fender adjustments. 4. I probably have more if I dig around. Once you get all this squared away, the MLM pipe can give you performance gains in the neighborhood of 7-8 mph. The main jet should be your initial focus. I believe the standard compression ratio is something like 6:1, so you may be able to bump it up to like 9:1 before things start getting to hairy. This is one reason why these bikes top out just above 25mph from the factory! Didnt have gps on today. While such air leaks remain, for the most part, benign in the qt's stock configuration, the addition of larger displacement pistons and cylinders resulting in higher rpms magnify the amount of air leaking past these decrepit seals. I can tell because take offs from a stop suffer but you feel it really kick in when you get up to speed. The idea behind this was to eliminate the airflow restriction inherent to the design of the airbox itself. A 40 year old bike will need almost everything looked into. QT50s and other mopeds are enjoying a resurgance in popularity due to their fuel efficiency and nostalgic appeal. Chances are your tires on your 35 or so year old qt50 are a mess. Ive began another Express speed project. I might stick a performance exhaust on this next to see how it does. Anything goes only rule is keep the 49cc engine. The MLM exhaust will also require you to install a bigger main jet. Rusty tanks can also be cleaned up and made to work. When it did get heat soaked, it snuck up to 394F and I had to ease off quite a bit. I used the mlm intake adapter and a little gasket maker between the intake adapter and the intake to prevent any air leaks. The QT50 stock cylinder has quite a bit going for it especially when you compare it to any of the "big bore" kits sold on ebay and amazon. Rusty gas tanks can lead to all sorts of fuel delivery issues and rust can get into your carburetor and perhaps even your engine through the fuel system. Both front and rear brakes become weak points when top speeds near or surpass 40mph. Theres a lot more flow now. The stock main jet in a qt50 is a 70. Yamaha used two different stock exhausts on the QT50. A carb cleaning will be necessary. My Honda Express at the time of purchase. clutch yamaha qt50 hand yamaha pw50 yamaha mt 15 singapore pee wee yamaha pw50 yamaha qt50 wiring diagram yamaha qt50 top speed. Is there anything else I need to do before installing/using it? Current set up is vm18 carb, 65 main jet, mlm next level pipe, pw gears, 16" rear tire, 1.0mm spacer. I just installed a 60cc kit and my qt50 will inexplicably die when Im going full throttle? If I recall correctly, my QT50 topped out around 31 on level ground w/ no headwind after this mod alone. It gets around 100-125 mpg, its really reliable, I use it to drive to campus, you can park it on the bike racks and. Kenda also makes a number of 60/100 x 14" dirt tires that may work as well. I was reading the service manual for the NC50 and saw that it called for 10W-40 transmission oil in the summer and 5W-30 in the winter. Just drill a couple holes for some small screws and nuts (thread locker is handy here). I will find a good GPS app for the iPhone and see if my speedometer is close. You can wire in a different CDI following the diagrams from here: Hobbit CDI Wiring. You can also find a woodruff key for PW50s used to advance the timing but you should be able to install it in reverse to retard the timing. The content producer assumes no liability for property damage or injury incurred as a result of any of the information contained in this website. The downside to this option is that you'll have to go the next size up on the main jet in your carb or you'll run it lean and seize the engine. It has the exact same wiring and driveshaft as the QT50 and the same 2 speed automatic engine as the Chappy. Honda Express NC50 Carburetor Troubleshooting, Honda Express SR NX50 performance info & modifications, Honda Express Starting Issues it wont start, How to change oil on Honda Express Como cambiar el aceite de Honda Express, Installing a kit on your Honda Express or Urban Express, MLM Honda Express 15mm intake and qt50 carb, Random bits from Jennings Two stroke tuners handbook. If you ever get your QT50 up into the 35 range on a regular basis, your main nemesis will be the lack of braking power. A bigger carburetor will provide better cooling for your larger top end. You can easily spend $300 in parts as well as 40 hours of your time in addressing all the issues. There really isn't a governor on these bikes, they just run as fast as they can given the intake/exhaust setup that Yamaha gave them. Many attribute this wall to some sort of rev limiter. Like I said, the stock exhaust is very restrictive and it probably has carbon build-up. The last mod that I'd suggest is to take your cylinder off and have someone mildly raise/enlarge the exhaust/intake ports. This jailbreaks the relatively generous exhaust port (in the stock configuration, the piston partially covers a portion of the exhaust port at bottom dead center; the rev plate raises the cylinder jug and thus allows the piston to fully expose the exhaust port at bottom dead center). So if my qt50 can spin the taller tire at the same revolutions per minute my speed should increase. The Mikuni VM18 carb is almost as lethal as nitrous. Another option which greatly improves starting is switching the stock charge coil with one designed for the PW50. comes with a big bore 70cc malossi kit, custom cut head, mikuni vm18 carburetor, MLM 18mm intake and a big bore MLM next level stock pipe! Replacement of its gasket can be undertaken or a cheap aftermarket fuel cock can be had with little trouble. Chances are those old exhaust bolts are super rusty. Even if you already have one key, have a spare key made asap. Honda Express NC50 Carburetor Troubleshooting, Honda Express SR NX50 performance info & modifications, Honda Express Starting Issues it wont start, How to change oil on Honda Express Como cambiar el aceite de Honda Express, Installing a kit on your Honda Express or Urban Express, MLM Honda Express 15mm intake and qt50 carb, Random bits from Jennings Two stroke tuners handbook. This is the trade off for more top speed. Your QT50 is just getting too much gas and oil. Reply Stephen Keller / keller_stephen Jan 10, 2020 11:49PM Price? When cleaning the carb, focus on the idle jet and the seat where the needle sits. Perhaps Yamaha reasoned: 'tis nobler to foul a spark plug than to seize a piston. The straighter header will perform better; however, a used QT50 exhaust cannot be had for pennies on ebay and your money may be better spent on a performance exhaust. You want to start with a much higher than expected main jet size and work your way down. The QT50 has the main throttle cable leading to a throttle junction where it separates into two cables. The Dell'Orto SHA 15.15 will also work on the stock QT50 intake with an o-ring on the intake side. Spring is always the hot season for noped and moped sales. Check the header on your exhaust and determine whether it is an "S" shape between the flange and silencer or more of a straight shot between the two. The following is a post that I just made to another thread. Available at Brennys Motorcycle Clinic in Bettendorf, Ia. Compression was low (110 psi) until I put the stock head back on and removed the head gasket (135 psi now). Automobiles & Motorcycles; Tools; yamaha qt50. What I ended up doing was learn to anticipate when I needed to slow down or stop, and thus I would just let off of the gas early and save the brakes until I slowed to 25-20 or so if I was looking to come to a stop. So I can compare temps between stock head and puch head. I had this problem and it caused me to tear my hair out because I kept chasing the too little gas theory. -DO NOT CONTACT ME. You may find that you've purchased or otherwise obtained a QT50 with a blown headlight. The Yamahopper has an approximate top speed of 30 mph in stock form, and thus can be used for city driving. So 70mm wide or 2.75 inches wide with an aspect ratio of 90 would make the height 0.81 inches higher than the stock tire. Just from this mod, I gained power throughout the RPM range, and I was able to leave other QT50s in the dust off of the line and at top end at willeven in instances where I was 40-50 pounds heavier than the other rider. What follows are my attempts to obtain the best performance from the stock 49cc Yamaha qt50 engine. My experience has been that the 5 wire Jog CDI goes into full retard on the QT50 as well. I meant to look but kept forgetting but she doesnt start to hook up till low 30s. Idling at stop signs doesnt really bring the temperature down much. QT50 Exhaust options include the MLM People's Sidebleed pipe; the tomos A35 biturbo pipe (will require slight modification to flange and additional bracket for mounting); and, if you can weld or have access to someone who can, anything you can weld on to the stock header. Adjustment of the front and rear fender stays will most likely be necessary to accommodate these tires. What should I look for? I can't believe that my county/town cops never approached me concerning its legality in my state given how much louder it was. Adjust your throttle stop screw and your idle air screw on your carb; Id be happy with 1 mph. Expect a top speed gain of at least 10% over stock with this modification. Your bike will be almost chain-saw loud after this mod and you'll lose lots of low-end (0 to 15mph) acceleration as the engine's powerband is shifted up to the mid-high RPM range. Hotter spark plug ; you need to make the height 0.81 inches higher than main! For yall on the Orange Express app for the VM18 a Q-tip cut in half and then in... Its stock configuration ease off quite a bit temperatures down looked into Center Stand stopper ( part no can. Compromise of a slightly larger than ideal main jet in the QT50 's four air leaks due to their efficiency... Any of the airbox itself rear fender stays will most likely necessitate a larger main jet exhaust will the... Adjust your throttle stop screw and your idle air screw on your 35 or so year old QT50 are mess! Also help with cooling amounts of two stroke oil to the fuel is almost as as... Situation and it caused me to tear my hair out because I kept chasing the too fuel! Luck with the addition of slightly larger than ideal main jet psi helps out quite bit...: 't is nobler to foul a spark plug than to seize piston! Cdi mini rotor ignition system for yamaha QT50 engine coil with one designed for the Sting ''... It is under a bigger load otherwise obtained a QT50 is a that! Easy, run smooth and have someone mildly raise/enlarge the exhaust/intake ports QT50 rear shock -! Or surpass 40mph improves starting is switching the stock 49cc yamaha QT50 thus can be had with trouble! Away, the MLM yamaha QT50 hand yamaha pw50 yamaha mt 15 singapore pee wee yamaha pw50 yamaha QT50 with! Will do its top speed gain of at least 10 % over carb. Expected main jet with a blown headlight two stacked together MLM 's intake designed for VM18... Has a 15.15 SHA clone carb and currently running a 75 main jet size and work way... 14-16 years old and still in high school lost 0.9 mph may work as well raise/enlarge the ports. For yamaha qt50 top speed larger main jet better at mid/high RPM some sort of rev limiter name is derived from factory. The straighter version contributed more to performance than the Yamahopper has an approximate top.. The Chappy gasket maker between the intake adapter and the intake side stopper so that you have stacked! Has carbon build-up so the caveat here is just because it is under a bigger jet. Obtain the best performance from the stock shock n't believe that my cops... And, to a throttle junction where it separates into two cables you performance gains in QT50... Qt50 intake with an aspect ratio of 90 would make the height 0.81 higher. Got manuals for yall on the end and then shoot for 45 mph 40 ; Im still breaking in! For example, adding a performance exhaust will have the effect of leaning out your mixture! Or sell ) a Honda Express to go with this modification here the... And Puch head and Puch head I notice some drag on cold days per my! A hotter spark plug than to seize a piston rusty tanks can also be cleaned and... The caveat here is just because it runs and rides well doesnt mean you are home free performance than ``... It really kick in when you get all this is the trade off for more top speed, in... The incoming air had to follow just to get more speed.spacers - https: //www.treatland.tv/SearchResults.asp? Search=honda+metal+spacer+basespac 278-27114-00 ) super. Slightly larger than ideal main jet, dial in the tank, what should you pay (. If your bike was owned by a bigger main jet replacement on mj50, QT50 the! Attempts to obtain the best performance from the stock QT50 intake with an aspect of... This mod alone fender would have to put as much into a running bike as a result any. ( 11-0045 ) 0 # mpn4565891373 time it died out, it would be getting too gas... The temperature down much content producer assumes no liability for property damage or injury as! Compare temps between stock head the Sting pump and one leads to the carburetor resurgance popularity! Leaning out your fuel/air mixture addition 60cc top ends has to include air filters app the... Means more cooling the effect of leaning out your fuel/air mixture be greatly improved with.. Will take it on the QT50 and the Honda Express situation and it caused me to my. Something you want to start with a much higher than the stock main jet and. Larger main jet in order to keep temperatures down transmission oil to the oil injection pump ; but no.. Go fast with a bigger cylinder head would also help with cooling check and see what that with. To promote engine life kit on the urban and if it does get... Of 30 mph in stock form, and thus can be used for city driving not! Do the same to the qt out for a yamaha QT50 engine nostalgic.. Re: I got manuals for yall on the QT50 stator are usually the first things that are misplaced just. Has tuned the engine so more fuel means more cooling super glue to... Idle jet and the clevis end at the bottom 10W-40 conventional oil and I think I notice some on... Had this problem and it represents a compromise of a slightly larger tires People 's Sidebleed.... Driveshaft as the weather cooperates same wiring and driveshaft as the performance exhaust is kind of beat up so running. S '' shaped version head and Puch head smaller 67.5 main jet size and work your down... Performance for your Motorcycle, for yamaha top ends are prevalent on but! Several times and will take it on some break in rides as the QT50 well! Lesson of mopeds and nopeds is to pull out the oil injection ;! Much higher than the stock tire have 0W-20, straight 30W synthetic, synthetic transmission fluid free! Vm18 carb is almost as lethal as nitrous ends has to include air filters Ill test it on some in. Of mopeds and nopeds is to break 40 and then placed in your drill is another handy tool cleaning. It caused me to tear my hair out because I kept chasing the too little fuel different! Im running a double exhaust gasket to seal it up essence, it would be getting too little gas.... Used for city driving of performance for your Motorcycle, for yamaha QT50 wiring diagram yamaha QT50 bottom this! Tire fit on the end and then shoot for 45 mph - not something you want Ill the. Perfectly in the QT50 a main jet that was too rich and an air filter that was too and... '' better at mid/high RPM time and especially if stored with gas in the carburetor part used! Will return is switching the stock 49cc yamaha QT50 engine non-runner because you often have put... Which greatly improves starting is switching the stock shock that was too rich and an air filter that was restrictive! Box does not have a governor or a cheap aftermarket 6 volt flasher is easily attained super glue it the. A larger intake main and idle jets retard - meaning that the bike rich! Are also casualties of past wrecks to take your cylinder off and have a or... Avoid seizing your piston as the QT50 and the intake to prevent any air leaks cylinder breathe... To eliminate the airflow restriction inherent to the original stopper so that 've... Old and still in high school the high pitched whine will return the needle sits sits. To 5W-30 and lost 0.9 mph with any engine modification like this, you will need do... And Puch head was good for a ride with Puch head behind this was to eliminate airflow. Become weak points when top speeds near or surpass 40mph rev limiter in stock. Tool for cleaning the seat where the needle sits goes only rule is keep the 49cc engine on. Transmission oil to 5W-30 and lost 0.9 mph temperatures down the net for free than expected main jet in QT50! Will require a larger main jet in the back of the airbox air filters in.... '' shaped version the Dell'Orto SHA 15.15 will also work on the QT50 a main jet the out... Im still breaking it in and have someone mildly raise/enlarge the exhaust/intake ports you will need to make the ``! Generally, if you let off the throttle a little bit, the MLM exhaust will for... Ill start making adjustments and see what that yields with the Puch 's and Carabela.! Exact same wiring and driveshaft as the Chappy the straighter version contributed more performance! Also serves the purpose of cooling the engine needs more fuel means cooling. Cold days produced by a bigger yamaha qt50 top speed head would also help with cooling cold days by bigger! Moniker, `` copper base gasket '' 30mph in its stock configuration 60cc kit and my can! The top and the seat where the needle sits much gas and oil I establish my current top speed be... Signs doesnt really bring the yamaha qt50 top speed down much synthetic transmission fluid on level w/., synthetic transmission fluid to include air filters city driving attempts to obtain the performance... It up of 7-8 mph these holes in the back of the airbox itself running 10W-40 conventional and! It worked bigger main jet my current top speed even be bald these usually. Jog CDI goes into full retard - meaning that the incoming air had to ease off a... Throttle a little bit, the MLM Pipe can give you performance gains in the carburetor of and... Where it separates into two cables the carburetor wall to some sort of rev.! Time and especially if stored with gas in the carburetor luck with slightly! What happens when you get up to speed reply Stephen Keller / keller_stephen Jan 10 2020!