Newb (Puch head)

Even though i've been at the moped thing for a few years, every time somthing breaks, i am bewildered and i feel like a newbie again :P that happen to any of you?

anywhoo, have any of you found any good ways of testing the head for leaks?

Also, do you need to have a speedo cable in the speedometer for the headlight to work on a puch?

thanks again for your time, guys

Re: Newb (Puch head)

There are several ways to find a leaking head gasket.

- you might be able to see traces of oil seeping out at the joint

- you might be able to hear it.. sounds like a squeal or a pop-pop noise

- when the bike is first started cold, you can spray some soapy water around the joint and look for bubbles or spitting

And of course, their will be some loss of compression pressure.

Re: Newb (Puch head)

Although it seems like most people who "work" on mopeds have never heard of it, there is this great tool called a compression tester! Really, its crazy that anyone would actually make a tool that is more acurate than watching for soap bubbles on the side of you motor, or just listening, cause those seem like pretty solid ways to make a definitive diagnosis, but you can get a thing that will actaully tell you exactly what the compression in you motor is. There are cheapo options that will probably be fine for what you need to do, and there are much more expensive options, which are probably not necessary for you. Go to the local autoparts store like autozone, and tell the guy at the counter you want a cheap compression tester. Then take it home and use it, and see if your compression is what the manual says it should be. If its not, tear off the head, and see whats going on inside. Scored walls, worn rings, bad headgasket?

Re: Newb (Puch head)

Oh yeah, and no, the speedometer cable does not supply power to the headlight. Interesting diagnosis, but NO.

Re: Newb (Puch head)

man thats a grouchy way to say get a compression tester. i thought that this was a place to get advice not ridiculed.

Re: Newb (Puch head)

IPOOKforFUN (if that's your real name..),

There is a very good reason that I left the note about compression for the last. Fact of the matter is - a compression tester cannot tell you if a head gasket is leaking. All it can do is provide a compression figure.

Example: My Solo engine has a compression figure of 145#. My friend's Solo has 165#. Tell me, is my head gasket leaking? (Don't even bother).

Even if you know the specified compression, or have a figure from a previous known-good condition, a low compression reading tells you nothing at all about what is causing the loss of compression. Could be rings / piston, bad crank seals, bad reed valve, blockage in the ports, a leak at the compression release valve (actually, most Puchs don't have one) - or, of course, a leaking head gasket.

The tests I suggested all can help to pinpoint a bad head gasket. Unless you own an amazing compression tester with an LED on it that says "HEAD GASKET LEAK", I don't know what use it would be in determining the state of the head gasket, in the presence of so many other variables.

By the way, I don't take this personally. But, if someone is going to come along and try to contradict good information with bad, I am going to set that straight. Fair enough?

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