jd a power block

[Anonymous-0]

I have a 38 a John Deere that I put a power block in. It starts good, runs good , but when it pulls at the tractor pull, when it starts to really pull and lugs at lower rpms it just dies. It pulled better with the original block with m&w pistons.
Any help would be great. Thanks

 

[Drew]

What head did you put on it?

What crankshaft are you using (stock 6.5" stroke or later 6.75" stroke)?

What pistons are you using? If using the stock pistons, what condition were the ring grooves in? New or used rings?

What condition were the bores?

I bought a 60 a few years ago with a power block that had less power than it does now with +.125 M&W's. The bores were worn and the pistons had sloppy ring grooves and it even had a broken ring.

 

[1945GMPULLER]

take the sediment bowl off, if you haven't already. put an inline fuel filter on. that made our G come to life. hope that helps

 

[Anonymous-0]

It has a stock crank. The power block is in excellent condition. Stock bore on the power block with new rings. It has a stock G carburetor. It sounds like a G but pulls like crap

 

[JDGnut]

Which head is on the tractor? what is the cranking pressure?

Someone will have to help me.. was that 6-1 PB setup to run on the 6.75 crank?? If so.. it could be loosing compression there.. and if you changed to a head with the combustion chamber in it...