686 - engine turn up

Comments and how-to safely. I heard that the trans on the 686 is a little stronger than on the 666 and that the 312 can probably put out more HP than the trans can handle. With this in mind I don't want too much of a boost.

I wasn't aware of that, I thought they were roughly the same. I think the later model 666's and early 686 had the D-312 engine with the later 686's using the D-310. Could this be the difference?

Ed

I know there is no comparison in the 886 that had the 360 American engine and the later one's that had the 358 German engine. I have operated different 886's some with each engine. The American engine in the 886 was all over the ones with the German engine. It was hard to imagion it was the same tractor.

Irregardless of tractor or engine, I don't believe you will harm anything in doing what you are proposing. I did much the same with a 560, stepped up rpm a bit plus had a technicion bring it to 100 hp, he then moved it back to 90 hp and there it ran for 17 years and 11,000 hours. 560 was suposed to be the one with the weak transmission and rear end, but at 11,000 hours it was my engine that blew into a few dozen pieces.