7060 low power

One of our 7060s is only putting out 125-130 at the pto. Dynoed 140 before we found it had low compression on cylinders 5 and 6. Took the head off and found the head gasket blown (has been 8-9 years since it was overhauled last). Sent the head off and it checked out ok except for some valves that they replaced as they didn't like how they looked. Sleeve standout is within spec. (motor has had sleeve problems before due to bad machine work). Got it all put back together again today and it seems to have more power and sounds a lot better. valves set at .015" hot. Dynoed only 125-130 after all this. Before we took the head off the pump and injectors were sent off, they checked out fine. Only getting 10 psi at the manifold when pulled down on the dyno, and when pulled past rated rpm still only 10 psi. Turbo was replaced two years ago, this is about when the power problems started but just thought we had boost leaks. I don't know what the problem could be, and has our local allis mechanic stumped. Any ideas or help will be greatly appreciated!

10 psi of intake manifold boost (30 psi gauge) with heavier than normal smoke would indicate a boost leak somewhere. 10 psi boost with normal to faint smoke would indicate lack of fuel delivery.

Have not ran a compression test since put altogether. smoke while loaded down was normal to me but not to excessive. It has the allis injectors so they aren't installed wrong. Puts a little blow by out but not a lot. When pulled down past rated rpm, it did dyno 150. Will have to check between the pre cleaner and air filter. Will also check the dampner pulley to see if it slipped. Could it be a timing issue?

What do you mean by after market air filters Mack? I believe its running a napa filter and was new before it was dynoed the first time.

Worked on a 7060 that would fall on it's face when a load hit. After makeing some checks found rubber hose out of air cleaner was sucking togather. He had replaced air filter from brand X filter from auto store, replaced it with Allis filter and no more problem.  MACK

this sounds like the fuel system has a restriction to the injection pump. Been a very common thing this spring!

No bio diesel has been ran through so that can be ruled out. Brand new agco fuel filter was put on before being dynoed the first time. Will check about a fuel restriction.

Blow through all the lines. Somewhere, you have a fuel flow restriction. Priming pump check valves also catch debris and plug up flow. 

DrAllis wrote: Another GREAT example of using a non-OEM filter and having a problem directly related to that non-OEM filter !!!!

Lol! I was just thinking the exact same thing!

I think we found the problem. Mechanic had a cranked up injection pump to put on to test and see if we could get more horsepower out of it. Got 160-170 out of it with maxed and pretty hot pump and figure that it should have been at least 200 with that much fuel. Boost only increased to 12. 8-9 years ago when we overhauled it dad did not have the cam ground. Well the cam is SHOT(the lobes almost have a point to them) and the lifters are wore, dad helped the guy take it out tonight. We are pretty sure this is the problem. Thanks for all the replies and thoughts on what it could be!! We were getting pretty discouraged here a couple of days ago and it really helped having some extra guidance from you guys.

We use Cenpeco 15w-40 diesel oil and have ever since it was overhauled 8-9 years ago.