QT50 brake question

Hey everyone, I just bought this bike and it runs ok but the brakes don't work at all. When you squeeze the handle...nothing. I bought new cables for it on eBay but I am yet to install them. PLus, I don't even know if that is the problem. Can the springs wear out?

Also, if I open the throttle all the way it stalls or coughs. Any ideas on that?

I just bought this thing and I am already ready to sell it. please help, thanks!

Re: QT50 brake question

sell it .. restoring mopeds isn't for everyone.

Re: QT50 brake question

wow, you're quite helpful. Why don't you kill yourself. Life isn't for everyone.

Re: QT50 brake question

hey you live in boston too. we've got plenty of moped riders around here. it doesnt sound like its too big of an issue. brakes are easy, you might just have to get new brake shoes. i doubt the springs are worn ive never head of brake springs wearing. when you say you open all the way and it stalls or coughs do you mean it starts to make a low pitched growl? if so tahts called bogging.you are probably jetted too high or too low. if you didnt make any changes to this bike it may just need a filter cleaning, pipe cleaning, carb cleaning, or all of the above. if your filter or pipe is clogged your bike will not get enough air and too much gas. taht is bogging. or maybe your jet is clogged and you are getting too much air (running lean). the brakes may just need a cable adjustment or something.

Re: QT50 brake question

If you want instruction, just ask. If you intend to surrender before you start, go ahead and say so. But doing both at the same time gives people the notion their efforts to help will likely be wasted.

Re: QT50 brake question

Thanks joeho, that was very helpful. I have worked on cars in the past so I understand the mechanics of what you are saying, but I haven't ever had a bike. Do you know a spot that has basic manuals for cable brakes? Does the BPL? I just can't wait to ride this thing now that it is getting nice in the Bean. Thanks again

Re: QT50 brake question

Mike Monigold /

If you go to mopedriders.org they have both the owner's manual and the repair manual for your QT-50.

I have a 1986 QT-50.

They get bashed here a little because they don't have pedals and are called a "noped". I just love the QT-50. Shaft drive, oil injection and real smooth and quiet. Pretty comfy, too.

Re: QT50 brake question

http://www.mopedriders.org/article_view.php?faq=2&fldAuto=45

this was the link...you are the man! thanks again.

Re: QT50 brake question

Ok, so today I installed the front and rear brake cables and it was a piece of cake. 1st question: How tight do the nuts on those things need to be? Should the spring be compressed before squeezing the handle or should it be elongated?

Second question: The bike still doesn't want to stop when I pull the handles. I can feel a little friction with the front brake and just barely any with the rear brake. does this mean I need new pads?

3rd problem: The screw head that will open the throttle cable housing is stripped almost completely out. How do I remove this screw since I can't get a grip with a screwdriver?

thanks again, and sorry for the elementary questions.

Re: QT50 brake question

wow, no one can answer this question?

Re: QT50 brake question

i'll answer your brake problem with, what i believe to be your solution, and then read the rest of your post.

new pads would probably fix your problem, but i don't think that you have to do that just yet.

there is a spring between the brake lever and the cup that the cable casing rides in. i'll bet you that if you chop that spring and remove about 1/3 of it, it will allow the lever to move the needed distance to get you the "contact" between the pads and the drum. i think your spring is collapsed and won't allow the lever to move far enough.

Re: QT50 brake question

the screw on the carb is essential to remove. i think that you mean the one phillips head screw on the top. i'm sure you've already tried vice-grips of every kind that you own. you might try to regroove the head with a hack saw blade.

i feel for you dude, if you were to grind the head off the screw, you still have to extract the remainder of it or drill it out and retap. if you don't, you can't use the carb.

as for your coughing and stalling, try removing the muffler and air cleaner for diagnosis purposes.

Re: QT50 brake question

thanks ed. so do you mean the spring has lost it's tension? I know the front spring is brand new, the rear spring is old. WHen i grip the brakes and the nut near the spring is tightened, the whole spring compresses into itself. I am yet to open up the wheel and see the pad depth. It sucks, but I can only work on it on Fridays, so I'm trying to find out if I should just order the pads now so I can ride this beast next week. thanks again for the insight.

Re: QT50 brake question

I actually fixed the coughing and stalling this weekend. Is the moped's back tire supposed to always be moving or when you idle should it be sitting still?

thanks

Re: QT50 brake question

the spring i am talking about it outside the rim, between the brake lever and the cup that the casing rides in.

also the brake lever has spline cuttings inside it. you can try removing the lever from the spline and re-attaching it at the next tooth, thus, opening the pads farther that before. that should take an 8MM tool to remove.

the underlying problem is, you need new pads, but there is a way to continue to get life from the old pads. but it's not indefinite.

Re: QT50 brake question

awesome, very helpful indeed. thanks again!

Re: QT50 brake question

I was a YAMAHA dealer here in Canada. The QT50 is a great little bike. the brake shoes are very small and wear out but are the same as the MJ50 and the little PW50 that is still made the same for24 years, very easy to get . The muffler can plug up and the motor will hardly run. Also you have to take off the exhaust pipe at the cylinder head and check for carbon in the exhaust port, don't scratch the piston while using a screwdriver to scrape out the carbon. Check the plug gap, must be .018" to .025" because the ignition is weak compared to a car. If I remember the brake springs are made in the shape of a " U " or horse shoe and would never wear out.

Re: QT50 brake question

take the muffler off an barbque it red hot an cook out the clog.the carb thing is another matter alltogether..if you can find one get a jewelers saw like you cut rings off injured fingers at the e.r.(long story) then cut notch in the screw..hope this helps

Re: QT50 brake question

yes. but there is also a spring outside the rim at the end of the brake cable. the lead ball at the end of the cable sits in the brake lever and the spring pushes the lever back. the spring also pushes against the cup that the cable casing fits in. as the lining wears off the pads, the spring squeezes more and more, til it's collapsed, and can't squeeze and more. the lever can't move far enough for the pads to make contact with the drum.

of course, i am only assuming that this could be his problem, because it's happened to me numerous times. chopping this spring is only a temporary fix, meant to supply braking until new pads can be obtained.

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