Results 1–30 of 49
Hi. Just got a Malossi 70cc kit for my QT50. I'd like to use the stick carb for now. Can someone please tell me where to start with jet size? Any other tips?
Both are 79s, so there's not a start/run feature. The wiring is the same on both bikes - they are identical except that one has an aftermarket coil and the other has the stock coil. It seems that the blue aftermarket CDI produces a much stronger spark on the bike, but the stock CDI does produce spark. And as I mentioned, the same stock CDI runs the other bike perfectly. Just to reiterate
I have a QT that will only run on the cheap blue CDI in the picture. I can take a stock CDI off my other running QT and it won't start. Any idea what's the problem?
In case this happens to someone else, the problem was a clogged muffler.
Son had ridden for about a month since I replaced a bad CDI and got it going. He finished riding the other day and it wouldn't start back. Has great spark and compression. Won't start even when putting fuel directly in cylinder. After kicking it over several times, heard the hissing/suction sound as seen in the video. What's going on? Youtube video
Hey guys. I wanted to post a follow-up on the solution. It was the CDI. I had two in my parts stash, threw one on and it fired right up. Put the other spare one on with good results. Put the original one back on, and problem returned. Hope this helps someone.
Hi guys,Thanks for all the suggestions. I've removed the gas cap, so venting is not an issue. It also doesn't matter if the exhaust is on or off. The clutch is in great shape, no broken springs and not binding up to the housing.Let me share one thing. just for kicks, I tried a new plug. The only brand new plug i had was a BP7HS. Started on about the second or third kick and ran wel
Hi Jack,Here's a video of the spark. Seems strong to me, and the charge coil measures 304 ohms, which is in spec IIRC.
Two questions...The cause of the heat soaking is the bad charge coil or is there something else I also need to deal with?Can you all recommend a good quality charge coil since the last one wasn't?
Ok, so mine measures 157. Clearly out of spec. I am very ignorant when it comes to electrical, so help me understand... Why would yours run a few minutes and die, them start back in a few minutes, but mine runs and never cuts out, but when I stop, it then won't restart for a very long time?
Thanks. It actually always needs the choke to start. So would you think it might be the original coil that's getting hot?
Hi,My QT50 will start on first or second kick. If i ride for just a short time, it won't restart until i allow it to cool for at least an hour. I replaced the charge coil and crank seals a year or so ago, and this is a new problem. Stock carb and 70 main jet. The exhaust is stock shell with the guts removed. Thoughts on what I should do to fix it?
I appreciate the thought, but does it matter that it's a 2 position switch? This is a 79 model.
Bump. Could use some help.
Son starting complaining that QT50 was getting hard to start and wouldn't restart after stopping. Wife said she noticed some smoke. I'd never changed crank seals on this one, so I did. First attempt after changing seals, it cranked perfectly, rode for about 5 minutes, it bogged and died. Watch the video. Spark is great, compression is fine, clear fuel line with good flow, spotless c
Ok, so I replaced the shaft assembly, and it is engaging properly. Please watch the video... the clutch is engaged when starting. You'll see that when I hold it still while starting, the wheel stays still. What's the problem? QT50 Wheel Spinning
Hey guys. Got a little ticked with my kid's QT50 and was trying to kick start it pretty hard and fast. Felt something "go" and now when kickstarting it, the shaft assembly is slipping on the pinion gear. When it does engage a little bit, the pinion gear isn't spinning freely on the axle. Instead, it is catching on the axle and spinning the wheel. Took it all apart and I se
Do you mean in the bystarter?
Hi Cameron,Yes, I've checked for air leaks and found nothing when spraying carb cleaner everywhere. I replaced all the seals last fall. I am not using the oil injector. Did away with that a few years back.
I've cleaned the carb what seems like 100 times, and I've checked and re-checked the float needle. I use fuel line to blow air into the inlet, and the flow stops when I raise the float to approximately parallel to the ground. Fuel is clean in the bowl. It idles fine, but my kid rides it about 2 or 3 miles with no problems, then irt begins bogging and it dies. It'll only run with
Thanks. That's a really good idea.
Thanks. He said he had already sold all the switches to someone else, but I appreciate the advice.
Hi guys,My 15 year old son is really loving his '79 QT50, but he's having a hard time using the indicators. Does anyone have the small thumb switch (just the black plastic part) for the indicators? I've attached a small image.
Here's a picture of the plug.
Hi. So I've moved the clip up one notch, run without the air filter, and tuned the carb according to Jack's instructions on his website. It's a tad better, but still bogs about 3-5 seconds after starting from a stop. Runs very, very strong after that. I will mention that the stock exhaust was cut by the PO in the pipe section, and I had a friend weld it back together. It's
Ok, I'll do that and let you know.
Not sure, never adjusted one. Where should it be?