I have just finished rebuilding a stock beetle engine however the starter can't crank the engine much much, mostly half a rotation or a full rotation occasionally. The battery is so so, it starts my other beetle easily but it may be suss, not sure.

If I remove the spark plugs then the engine turns over easily with the starter. The starter is 12v, I got it used, so I don't know if it's got problems. I cleaned up the terminals and opened up the starter and cleaned up the copper commutator? .

I installed a new conversion bush (the car has a 6v gearbox, I clearanced the bell housing for the later 12v flywheel).

For the battery I left it to charge all night and tried in the morning. Same result.

I can turn over the engine by hand ( with a bit of effort).

So any ideas what it could be?

Thanks

retard the timing a bit and try it

Just tried it, didn't work, engine still hard to turn over

Rob ,do you have another battery you could try,or maybe treat it as a flat battery and jump start it with leads to see if it turns over quicker

I'm no engine builder...
but
just sounds like too much compression...

triple checked the valves/ tappets..??

squirted oil into the spark plug holes?? and got oil pressure pumped up before putting the plugs in???

If it turns over with the plugs out... it seems OK to Me...

but its not going to start if it doesn't turn over the engine..

Maybe the starter motor??
try a screwdriver across the terminals of the starter solenoid...
or the starter throwout isn't working with the wrong ring gear??? starter pinion gear is jamming in the ring gear??


My engine is very hard to turn over by hand...
easy with the plugs out... so heaps of compression..

LEE IMHO

Yep quadruple checked tappets, compression bit stiff when turning by hand, but similar to my other beetle. Tried jump starting (didn't have jumper leads so used some wire I had around) slightly better. Had 2 rotations, so maybe battery is too weak. I'll get some proper jumper leads and give it another go.

Ok so I tried jumped starting with proper leads off my golf AND having the battery charger on at the same time. I can turn over for 5 - 10 seconds but then it's not cranking so I assume not enough current. I give it a 5 minute break and try again.

I managed to get an occasional pop from the exhaust but it won't start (probably more problems!). However it might just be that the engine does not have enough speed and time to start up.

So could it be likely a bad starter motor?

Do a compression test but my 1200 has so much friction from the new rings that I can't turn it by hand yet the 6v on 12v electrics starter turns it over fairly well.

So if the compression is stupidly high it will have trouble, otherwise it's a battery or starter problem.

Solved!! Well it turns out it was the battery after all. I bought a used battery and hey presto it turns over happily (doesn't start but that's another issue LOL).

The first battery still starts my other beetle easily (probably would start with a AA battery!) but it looks like it's getting tired. First thought my battery charger was playing up cause it would never charge past 75% anymore, but after borrowing my neighbours charger, same thing. I'm speculating that jump starting wasn't too effective cause I had to use 2 sets of leads (clamped to each other, so resistance would be higher, thus less amps??).

Thanks everyone for the advice.