Problem getting 760 back together

I bought a weller 760 stoker that had a 12:1 compression piston so I changed it to a 10:1 compression piston to make it more reliable.I think I am having timing problems?
I had my automotive tech do the piston swap and he had everything marked but someone move the crank when things were apart. The engine is now in the rhino and cranks free with spark plug out but is hard cranking with spark plug in. The starter struggles to crank the engine it takes 2-5 seconds before cranking then cranks the motor then stops cranking. We put it on TDC moved the timing chain one tooth in both directions but still not right. The crank also has three different timing marks?? different then my original engine which we compared it to and only has one mark. Any ideas???
Thanks, Kevin

battery ?

compression relese working?

nope used a new battery jumper just in case had 12.8 volts.

degree the cam!

While yer at it check and be sure the compression relese is working.

When viewing the engine from the passenger side, the engine spins counter clockwise. The 3rd mark on the flywheel is TDC. The two that come before it also have a line connecting them, sort of looks like a reaaly wide "H". The "H" mars are the firing marks, that is when it fires the plug. Use only the 3rd line for tining the cam.
What cam is in the engine? If it is a small cam, it may just have too much cranking compression for the engine to turn over well. In other words, there may be nothing physically wrong at all.
Does it still have the decompression mechanism on the cam?

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760-484-0986

whats small chris. i have a big cam, i thinck. and mine turns over slow it has a 185 psi crancking compression.

Something with relatively short duration. Less duration generally means less overlap, and more cranking compression. If his motor has a Mudbuster or similar in it, I wouldn't be a bit surprised if it is hard to spin over.

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760-484-0986

i agree i rana 445 lift with a 224 dur. and it turned slowly

I would check the Valve lash on the ext. Cam, if it is too high of a Gap the Decompression release will not work and let it stall when cranking it over, which to me is what you are describing.

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Bobby

[quote=s2k1;437956][quote=mdban5800;437949]Thanks Chris & everyone, we got it figured out once we new the timing mark was right(3rd mark), BAD STARTER!!!! that came with the used motor. I will switch it out tonight got the engine running once it was cranked past the compression stroke with the weak starter.

Well I changed my starter and it still starts the same. It seems to run fine once started but I am afraid of burning up the starter. It was a race engine so I am guessing the cam is drastic enough to cause this slow cranking. Do they make high output starters if this is normal??

my old race motor did that sounds like the comp. release was removed. mine was i had to bump the starter to get it to start

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