murray moped wont start

I have a 1980 murray moped with a 1.5hp puch one speed engine. I feel that I have done everything that I could to make this ped start. I got a new piston and rings from the moped warehouse and instaled them perfectly. I cleaned the carb and the gas tank which does have a little rust. The bike Has a very good spark. Gas is getting into the carb bowl. I have the bike turned on! I dont know what else there is to do. I even sprayed starter fluid into the carb and it would not even spudder. Could it be bad gas? Please any suggestions would help.

Re: murray moped wont start

possable blown crank seal?

Re: murray moped wont start

Keith Wallace /

How the hell could you diagnose a blown crankseal? If you have gas, and spark, you could be missing compression. Do a compression test (some auto parts stores will let you borrow or rent a tester cheap), and make sure you're showing 120psi. (you have to test it with the throttle wide open). If it doesn't check out, you need to go over everything, make sure your gaskets are seated properly (no old gasket material behind them), even pressure on all your bolts, no air leaks around the carb, intake, airbox, etc. If your compression checks out, go through everything, especially the carb, again VERY carefully- put an inline fuel filter in if your gas tank is suspect, and take everything out of your carb, and run fine wire and blow everything out with an air compressor, even if you think you've gotten it all before. Is the carb float functioning properly? Is your gas cap venting? Go through Fred's guide in the resources section once or twice, and it'll run be the time you're done. The puch 1 speed on the murray is a strong, reliable engine.

Re: murray moped wont start

stephen /
OP

I know that I have enough compression because I just rebuilt the top end on it. I have the muffler off and can hear the compression very loudly. But I will cheak with freds guide. What is the puch gas ratio? I think fresh gas may help.

Re: murray moped wont start

Tab Patterson /

Some things to check...

make sure the taillight bulb is good.

Also, if the horn has been messed with (i.e. wires cut), the bike may not start.

Is your plug wet? Sometimes, a plug may seem fine outside the bike, but won't spark enough when installed. A wet plug means you are getting gas, at least.

If I were you, and fed up...I would replace the plug, check the points, condensor and timing...check the rear bulb...and go through every inch of the carb. But, if there is no sputter with starting fluid, I would hold off on the carb for last.

Re: murray moped wont start

Keith....Ryan might be right. This happened to me and I had compression,gas to carb,spark,etc., and I checked the stator plate and happened to look behind it and the seal had blown completely out. Just found the problem by accident.

Of course,crank seals are kind of a long shot, but they fit this case since Stephen hasn't said his spark plug was wet after trying all that time? don-ohio

Re: murray moped wont start

Keith Wallace /

True Don- my point was- just because you installed new rings doesn't mean you have ample compression. You need to check it to make sure everything was installed properly, there are no leaks, etc. Go through the guide, it'll help.

Keith

Re: murray moped wont start

Jason Luther /

when i first got my puch it had good spark ( so i thought) it just ended up having the totally wrong spark plug in it. moral? get a new plug, your spark may not be good enough.-jason

Re: murray moped wont start

stephen /
OP

Thank you guys for all of the help. I got home to school today and tried to start the ped. It didn't start of course. I decided to recheak the spark. I took out the plug and put it against the cylinder and pedaled and the plug fired like it is supposed to. It was wet when I took it out. So just being curious it took the plug from my tfr and stuck it in the puch. The bike started right up. I was so happy. So i guess my plug was just fouled. But the weird thing was that yesterday I took out my puch's plug and sparked it against my cylinder and it fired good. But when I put the plug that I just tested back into the cylinder head the bike would not start. I don't know but it works know and thats all that matters to me. Thanks again for the help.

Stephen shope

Re: murray moped wont start

As long as it runs, that's great. BUT please shut the gas off to the carb when you shut the engine off. At least until you verify it's not flooding the cyl. with unmeasured fuel? don (:^D

Re: murray moped wont start

Tab Patterson /

That's happened to me many times. The plug fires great outside the bike, but not when it's installed. Glad you got it runnin'.

Re: murray moped wont start

Michael Miehle /

Just be cause you see spark doesn't mean the ped will run. I had this happen with my Snark. I did everything except decarbonize the head. I pulled the head cleaned the crap off, and it ran like a champ. Also have fixed a puch that wouldn't run by properly setting the plug gap. Looked great outside sparking but I guess the bad gap threw the time off.

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