Also went down to 14 tire. Stock cylinder head is horrible on cooling. Makes me wonder how anyone could really go fast with a stock head. Does the owner have title? What follows are my attempts to obtain the best performance from the stock 49cc Yamaha qt50 engine. Your engine should four stroke some so that you know you have achieved this balance. Day 7 I opened up the side transfers on the cylinder skirt. 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. yamaha qt50 big bore party pack with pretty much all the stuff you need! Damn that was sweet! Adjust the oil injection pump; Half the package or less is plenty. 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, using a key other than the Yamahopper one. What should you pay for (or sell) a Honda Express? Call 563-359-7222. 3. Tire width goes to 3.15 inches and top speed goes to 32.71 mph. We are back up and running. . I notice sometimes at full throttle it will run rougher, make a different noise, seem to hesitate and check up. Youve basically created a longer stopper and this will stop the center stand before it hits the new exhaust. On a large ride, I was able to keep up with the Puch's and Carabela's. Eliminate your oil pump and just use pre-mixed gas/oil at a specific ratio (50:1 or so); To combat this, many riders have eliminated the oil pump and replaced it with an oil plate block-off or an automotive freeze plug. These bikes like most Japanese bikes of the time came with excellent finishes in both the paint and chrome, though the plastic parts on many of these have deteriorated over the years. Chances are your tires on your 35 or so year old qt50 are a mess. Dont try that with those niche kits. This is the trade off for more top speed. I'll make videos of each top speed run and post them here. It is considered a motorcycle by most states. Of course, this would retard the timing at all rpms and may not be ideal. Stock Configuration and Basic Performance Upgrades, https://www.mopedarmy.com/w/index.php?title=QT50_performance&oldid=24781. With all this in mind, what should you pay for a Yamaha qt50? Day 5 So I went from 34-35 with next level pipe to 39.7 with circuit pipe. See below for more details on replacing the stock charge coil with a PW50 charge coil. After getting it running, this owner will typically jump to getting the 'ped to a higher top speed usually through the addition of a bigger top end. 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. As a result, it cant burn that fuel and starts four stroking. 6. In addition 60cc top ends are prevalent on ebay and amazon. If it goes slower than this, negotiate accordingly. Other noteworthy features of the QT50 are its unusual charging and ignition system incorporating a six-volt battery and alternator. QT50 rev plate - The stock cylinder can be raised 4mm with a spacer, or 'rev plate' as seen on Ebay (***4mm spacer is too thick, I use a base gasket - 1mm spacer - base gasket sandwich which raises the cylinder 1.5mm and that should allow the piston to clear the exhaust port fully***). Yamaha QT50 Cables & Brackets. Im still breaking it in and have encountered and overcome several hurdles already. -DO NOT CONTACT ME. > Hey, so do I. I'm running a 60cc top end on my QT with the Towny bottom > end. You should see a large circle of light through the main jet and a much smaller circle of light through the idle jet. Ron Peek / yamahauler. Performance modifications will only exaggerate current issues. Yamaha may have intended that the bike run rich to promote engine life. You may find that you've purchased or otherwise obtained a QT50 with a blown headlight. Traduire le commentaire en franais. If it doesnt pass all the tests above, subtract as follows: Very rusty gas tank requiring replacement $80-100 deduction; 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. New bolts with some anti-seize compound are recommended. Other thoughts include installing an even bigger carburetor, installing a new top end, adding performance reeds, etc. So if my qt50 can spin the taller tire at the same revolutions per minute my speed should increase. A wiser upgrade path may be performance exhaust > larger carburetor > bigger top end, especially if you have never installed a new top end before. Add a new exhaust gasket and put a little anti-seize on the new bolts before installing. 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). In the end, I was able to get the QT50 consistently up into the 35-40 mph range even on slight uphills, and I was able to almost hit 50 going downhills and also by catching a lucky draft from an SUV on level ground (which was probably one of the dumbest things I've done in my life so far). Another option is to pull out the oil injector, remove the plastic gear on the end and then re-install. Another culprit in QT50 excessive four stroking is the oil pump. A bigger cylinder head would also help with cooling. Plastic parts may be the most difficult of all as they did not age well if left in the elements. Couldve easily seized it with an extended full throttle run. 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. Re: I got manuals for yall on the net for FREE. Ill be interested to see the difference in head temps as compared to stock head. If the bike doesnt run dont pay more than $150; What should you pay for (or sell) a Honda Express? Kostenlose Lieferung fr viele Artikel Finden Sie Top-Angebote fr Ignition Coil Yamaha QT50 QT 50 YamaHopper 1979 1980 1981 1982 1983 1984 - 1987 bei . -DO NOT CONTACT ME. The stock main jet in a qt50 is a 70. Engine failure is imminent. My Yamaha QT50 . Puch head arrives Monday. Day 3 I put a bigger pilot jet in the blue Qt. Again, a performance exhaust will call for a larger main jet in the carburetor. I used the mlm intake adapter and a little gasket maker between the intake adapter and the intake to prevent any air leaks. Carb needs replaced subtract $35; 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. In short, here's what I did to my QT50 to make it a little bit peppier. Ive used the vinegar and salt method but now mainly use EvapoRust. New and used parts are often found on eBay as well. I had cyclekeysonline make me a $10 key for it and it worked. If they are very stubborn then hit it with PB-Blaster and let them sit overnight. Ride, handling, braking and, to a small extent, top speed can be improved with them. The header on my stock exhaust is kind of beat up so Im running a double exhaust gasket to seal it up. At full throttle, the bad seals may let in so much air that it causes your bike to die. I've got several other ideas but will reveal them one by one as I make progress from test to test. It has a high rpm retarding feature that keeps the temps down by retarding the ignition timing as the rpms increase. When you do successfully extract them, replace them with new bolts of the correct size. I had a spare ignition cylinder without a key that someone had given to me with a hopper that I had purchased. 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. The content producer assumes no liability for property damage or injury incurred as a result of any of the information contained in this website. I think 2-4 mph is a bit optimistic. 1. You can help Wikipedia by expanding it. Install a new and bigger rear tire. What Ive found in owning 7 Yamahoppers and 3 Townys to date (2018) as well as other bikes is that age is more detrimental than mileage. Thats an almost 2 mph increase by just changing the rear tire. Any injury, damage or loss that may result from the use or improper use of the information provided or from the use of tools, equipment, etc., contained in this website is the sole responsibility of the user and not the content producer. Having fun on the Yamaha qt50 Ha ha ha. 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. That is just not going to work well. If you lose the oil pump, you also lose some of that snap-back tension. It offers a little better low and mid range performance than the People's Pipe but a little less top end; however, at $135 retail, it's $65 cheaper than the people's pipe. I never ran into overheating problems, nor did I ever have a mechanical breakdown because I kept up on its maintenence. This leads to hacking into the wiring. I can't believe that my county/town cops never approached me concerning its legality in my state given how much louder it was. My Honda Express at the time of purchase. Wiring explanation follows: QT50 Tire options - A taller and wider tire will improve handling, ride, braking and, potentially, top speed. yamaha . FREE delivery Jan 25 - 31 . 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 not a moped since it doesnt have pedals. So my first top speed experiment will be to try a lighter weight synthetic oil to see if I obtain a noticeable speed increase. Commentaire fait aux tats-Unis le 10 novembre 2019. Such puny gains are not going to satisfy your QT50 fanatic. You will need to replace your main jet with a bigger main jet. Didnt have gps on today. 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. When cleaning the carb, focus on the idle jet and the seat where the needle sits. This does not mean that all four stroking is bad. Future topics to be covered: 6. 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. Reply Tim Doll / barneyfife OP Jan 11, 2020 12:19AM Sorry about that ,missed one small detail $650 Reply Bob Naske / bobqt50 Almost there. 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. These are awesome mopeds, they don't weigh a lot so they are nimble, being a moped it's legal to park anywhere a bike can (including bike racks), goes about 30 mph with a twist. A popular choice is the IRC NR-77 moped tire: 14 x 70/90. Worth it? Stock main jet size in the QT50 is a 70. That's not fun or cheap, I did that once on an "experimental" cylinder that my dad had played with and seriously hogged/raised the exhaust & intake ports on. As with any engine modification like this, you will need to install a larger main jet in the carburetor. Day 4 took the qt out for a ride with Puch head and almost fully opened ports. Adjust your throttle stop screw and your idle air screw on your carb; The Jog CDI is purported to retard timing at higher rpms and thus lead to lower operating temperatures. Top speed run, super windy and about 69 degrees. The QT50 does not have a governor or a rev limiter. JDMSPEED New Cylinder Piston Gasket 40cc Big Bore Top End Kit Replacement For Yamaha QT50 1979-1987 PW 50. A too lean mixture can cause serious engine damage. Youll thank me later. Day 1 49cc engine is on my blue qt50. Also check the foot pegs to see if they are bent. 3. It has the exact same wiring and driveshaft as the QT50 and the same 2 speed automatic engine as the Chappy. The oil pump is reputed to add excessive amounts of two stroke oil to the fuel. Id be happy with 1 mph. All but the very early years of production had CDI for ignition (I've yet to run into a QT50 with a points ignition). Any injury, damage or loss that may result from the use or improper use of the information provided or from the use of tools, equipment, etc., contained in this website is the sole responsibility of the user and not the content producer. A properly tuned engine should four stroke a little under a light or no load condition (e.g., going downhill). 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. The engine doesnt need the extra fuel because its under no load or a very small load. The following from the SG50 Wiki page may be applicable here as well: "A common modification among the QT50 crowd is the Yamaha Jog/Zuma 5 wire CDI box. Any 28 or 29mm air filter is most likely an improvement over the stock air box (although many have resorted to drilling speed holes into the stock air box). 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. A larger carburetor may even be a better choice than the stock carburetor with a larger jet. I ordered a puch 40mm head. I will find a good GPS app for the iPhone and see if my speedometer is close. It four-strokes fairly easily in the stock configuration so that you don't overheat and soft-seize under low load at full throttle. Day 6 I let her eat today. Ive got several other ideas but will reveal them one by one as I make progress from test to test. 1. What you are really experiencing is the engine four stroking as a result of too much fuel in the combustion chamber. Adjustment of the front and rear fender stays will most likely be necessary to accommodate these tires. The lesson of mopeds and nopeds is to find your next bottleneck and fix it. What you are experiencing is a phenomenon known as four-stroking. Install different clutch springs to get back your low end. 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. 41.6mph. 9. 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. Stock plug is an NGK BP4HS. QT50s were popular in the late 1970s and 1980s because of their ease of use and maintenance, extremely low gas mileage, and legality in most U.S. states among pre-driving-age teenagers. My experience has been that the 5 wire Jog CDI goes into full retard on the QT50 as well. I put perhaps 15,000 miles on this bike (the plastic speedo/odometer housing in the front hub failed after about 9,000 miles due to these speed mods), and I cannot stress enough of the importance of taking care of your air filter and making sure you keep that oil reservoir full. Another option is to obtain a headlight for a Honda C70. Cylinder Piston Gasket Head Set Fits Yamaha PW50 (1981-2018) Bore 40mm. I ordered a puch 40mm head. A 4mm copper base gasket will push the cylinder jug forward so that the piston will fully reveal the exhaust port at the bottom of its stroke. 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! New cylinder head. The temperature gauge will be your other. At top speed and when the engine is under little load, you may hear the engine note change tone from a high pitched whine to a lower and rougher growl. Maybe sooner if you want to be more cautious. 6. Controlling the heat produced by a bigger top end and/or a performance exhaust is a common issue with QT50s. But Im not sure how far down the rabbit hole I want to go on this one. Im looking at a QT50 that Im thinking about buying. A temperature gauge is mission critical to keeping your piston from soft seizing. 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. clutch yamaha qt50 hand yamaha pw50 yamaha mt 15 singapore pee wee yamaha pw50 yamaha qt50 wiring diagram yamaha qt50 top speed. Or adding a bigger top end will require other modifications in order to achieve the potential of the new top end. Do this little by little in combination with PB-Blaster. For Cable Housing. Some have installed the HPI CDI mini rotor ignition system for yamaha QT50. What should you pay for (or sell) a Honda Express? You may also choose to richen up your jet needle by moving the clip down one or more positions. 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. If the bike doesn't run - don't pay more than $150; For every 1 mph below top speed of 30 mph, subtract $15-20; Bent forks such that it pulls hard to one side when riding - subtract $85; Headlight doesn't work - subtract $45; No side covers and you really want them - subtract $100-125; Wiring issues - subtract $100; Yamaha's conservative approach leads us to our first performance upgrades. 2. 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. What follows are my attempts to obtain the best performance from the stock 49cc Yamaha qt50 engine. I also read on mopedarmy.com (concerning the Suzuki FA50) that if you went from 20W-40 conventional oil to 10W-30 synthetic oil, you would obtain a 2-4 mph top speed increase. Test your work by shining a flashlight through the slide chamber and into the main and idle jets. I hope compression gets better as the rings seat. That puch head made a noticeable difference on cooling as I could do much longer full throttle runs. The simplified driveshaft setup makes wheel changes easy. A Q-tip cut in half and then placed in your drill is another handy tool for cleaning the seat. This filter will allow the engine to get more air. Wiring issues subtract $100; It's simple, maintenance-free shaft-drive contained in the single-sided swingarm eliminates chain maintenance, safety and wear concerns as well as weather wear factors and contributes to the durability and ease of use of these tiny motorbikes. 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. Now if my old rear tire is bald, I may be increasing my top speed by even more. $650 in Ohio may be the same as $900 in California or New York. 10. The VM18 will require MLM's intake designed for the VM18. You more than likely over-jetted. 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. 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