I just installed a kit on my 1978 Puch Pinto. When finished it started out that there was no compression. Then I took the engine back off and cracked the case and reset all the parts. Now I had way to much compression without the clutch even being pulled. I tried to start it and now there is no compression again. Also I notice when peddling the Moped both chains move when peddling it like a bicycle (I believe this isn't normal. I am not sure what may be the cause. Please help?
What was installed: New CM crank shaft assembly, Maxi cylinder head 44mm, DMP cylinder, proma exhaust, and Delllorto carburetor
Oh buddy.... sooooo many things could be wrong. First this should be posted in the repair forum but it is ok I'm sure.
Low compression is usually going to be a top-end issue unless your seals are not seated properly on the crank shaft sides. The leak is going to be at the base or the head of the cyl.
I would address the top end leak possibilities before breaking down the whole bottom end a third time.
I am also assuming you have a proper "gasket" on your case halves.
I just tore off the top end to check the metal seal springs around the cylinder to see if they were seated properly All my seals are good and brand new. it seams as if something is slipping because I do have good compression when I turn everything by hand. Also it is as if the clutch isnt doing anything engaging anything.
What is a metal seal spring? Do you mean Piston rings?Is your starter clutch engaging?
You did way too much at once, always a no-no.
Yes the piston rings. and no the clutch is not engaging. I just came down to that conclusion. when I pull the clutch handle I can turn the peddles without any additional friction as it would when the clutch engages
Have you adjusted the clutch cable to make it so that it pulls the starter plate to the correct position? If you just hook the cable up at its longest it probably wont pull the plate to engage it. Tighten up the cable until it engages the plate, then back it off a few turns so that it is fully engaged when the lever is pulled.
Yes I have tried adjusting the clutch cable. As it is pulled as tight as I can get it still does not engage the clutch. Do you think the clutch is bad? and is worn out enough that it slips with the newly added parts that may cause a lot more compression?
Did you put the rings on the piston with the markings facing up and with the correct top and bottom ring positions, and is the arrow on the piston crown pointing toward the exaust? All of that matters.
> Pushrod Fifty Wrote:
> -------------------------------------------------------
> Did you put the rings on the piston with the markings facing up and with
> the correct top and bottom ring positions, and is the arrow on the
> piston crown pointing toward the exaust? All of that matters.
I have been told the piston direction matters. And obviously with reed kits it does since the piston has windows in it, but I recently pulled the jug off a bike I had that was running for years. Turned out the previous owner had installed the piston with the arrow pointing up. I flipped it of course, but no difference in the bike at all.
If you can manually engage starter lever and you can't get it to grab, it's either assembled incorrectly or missing pieces.
If you can manually engage it and turn it over, your cable adjustments are bad.
If you can manually engage but it locks and won't spin: bad shimming in clutch or piston hitting head.
What's your squish? What's your comp numbers?
Photos of the trans with cover off?
Problem solved
Sweet
> Pushrod Fifty Wrote:
> -------------------------------------------------------
> Sweet
Agreed ... that it's solved .
Pretty selfish to not share how that happened .
Sorry I was in the process of looking up the right terminology. Anyway, the pin that goes into the axle of the new crank shaft was to long. And the plate was not being pushed against the clutch. Even though there was high tension on the clutch cable it was not engaging the clutch due to a spacing problem.
> Graham Strauss Wrote:
> -------------------------------------------------------
> Sorry I was in the process of looking up the right terminology. Anyway,
> the pin that goes into the axle of the new crank shaft was to long. And
> the plate was not being pushed against the clutch. Even though there was
> high tension on the clutch cable it was not engaging the clutch due to a
> spacing problem.
Good to know . Thanks for that . ;)
It sounded more like you figured out the clutch deal, they are finiky, I used to keep my cable adjust lock nut loose so I could adjust it on the fly, depending on moon phases and temp changes.. hehe
You must mean your small end crankshaft connecting rod, did you have the wrong length rod? Hope you have both c clips on your wrist pin.
Sounds like he's taking about the guide pin for the starter plate thrust bearing
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