Motorcycle Repair: HOnda hobbit PA501, piston rings, oil mixture

Question
I bought a PA50 honda hobbit for about 200$ and it worked amazingly for about a week than it wouldnt run with some effort i can get the engine to start but only for a few secounds than it dies again. i have a shop manual and i know what that says and i have checked most of what it says. I have checked where the fuel goes from tank through the gage and everything is fine my thoughts are that its not getting enopugh fuel or air but i am not good with engines. If you could list a few things i could check its a very strait foreward bike and is a nice ride that i would like to be using. Thank you for your time  Arron

Answer
Arron, here is a bit of interesting info...
http://100megsfree4.com/honda/h0050/moped.htm

Hopefully, you were/are aware that it is a 2 stroke that needs a gas/oil mixture to run properly. If you run it on straight gas, it will seize quickly, ruining the piston, rings and the cylinder bore, to begin with.

You need to check to see if you have spark, first. No spark, then no running. You could have a fouled spark plug and/or the ignition points may need cleaning and adjusting.
If they are gapped to about .014" (widest point during the rotation of the flywheel), then they should open at the F mark on the flywheel and you should have a spark. If the points are clean and the spark is intermittent or not there, then the condenser has died, most likely.

You could have blocked fuel jets or passages, from old gas in the tank or rust/debris floating down to the carburetor and blocking the float valve or plugging up the idle jet. Carb settings depend on the year of the machine, but I guess you have that info in the shop manual.

Other odd things 2 strokes do are to plug up the exhaust port and the muffler with carbon! That pretty much stops air flow through the motor...

Try to get a compression check on it. 115 to 170 psi is necessary.

Other areas of concern may be the seal behind the flywheel end of the crankshaft or bearing failure on that end.

Piston condition can be seen, somewhat, by pulling the muffler and looking into the exhaust port, while slowly turning the motor over. If the piston isn't scored and the rings are not broken, then the top end may still be okay. You can always pull the cylinder head off, for inspection of the bore, as well.

Hope this gets you going in the right direction.

Bill Silver