F250 compression #s

[99yam40]

I would have liked to see a leakdown test done with a known good tester to see if the cam timing at TDC
allowed/showed some leakage on one bank due to it being out of time
but that is just the way i am

[formula29]

I still do not understand how/why someone would put one wrong VCT sprocket on the same side of both motors?
where did these come from?
they should not have come from the motors they took apart to repair.

A big question from me is, does the YDS show the cam timing problem the same on the other side now? just to verify that the timing problem followed the sprocket?
it should have if that is truly the problem


I am guessing you will be contacting the shop that sold you these motors to have the proper sprockets/parts replaced

I have no idea on how someone could do the same thing to two motors, but hell, the timing belts were on upside down too, I'm not quite sure how you do that, I bought them from a Yamaha dealer and I really don't think they did this to them, it probably happened when the powerheads were replaced, it would be nice to receive some sort of compensation sense they were sold to me with a clean bill of health, so far not so much.

I have not started the engine to see if the timing problem followed because I am not going to bolt everything back up until I get the right vct, but it had to follow, that is where the increased compression is coming from.

[zenoahphobic]

I have no idea on how someone could do the same thing to two motors, but hell, the timing belts were on upside down too, I'm not quite sure how you do that, I bought them from a Yamaha dealer and I really don't think they did this to them, it probably happened when the powerheads were replaced, it would be nice to receive some sort of compensation sense they were sold to me with a clean bill of health, so far not so much.

I have not started the engine to see if the timing problem followed because I am not going to bolt everything back up until I get the right vct, but it had to follow, that is where the increased compression is coming from.

A good mechanic is consistent. Even a person who thinks he/she is a good mechanic but are not, can be consistent - that would explain the reversed belt and perhaps the placement of the cam sprockets, but it might be reasonable to assume the wrong sprockets were ordered or more likely came off a used (for spare parts) engine. What puzzles me is what was wrong with original correct sprockets, and of course what engine were these replaced off/for?

And Boscoe, Rodbolt might be in hiding, but it usually doesn't take much bait to get him to bite.

[TownsendsFJR1300]

Back to the thread, any updates Carmen??

[formula29]

Hey guys, I figured everyone was about tired of hearing about leakdown, differential, and compression test, I can laugh about it now. I bought another used vct pulley so I had a matching set and it is all good now, even compression all 6 cylinders, 170 lbs, and the intake cam timing was even on both banks as well @ plus or minus -1 to 2 at idle, The best guess I have is in 2005 and early 2006 they used the one vct pulley which added the timing and gave 195 psi at cranking speed, and I'm just guessing here that sometime in 2007 they switched to the latest vct pulley which yields 170 psi and basically no cam advance at cranking speed, and my biigest guess is that when these powerheads were redone there was one motor with the old pulleys and one motor with the newer pulleys and the tech mixed them up??

[TownsendsFJR1300]

Hey guys, I figured everyone was about tired of hearing about leakdown, differential, and compression test, I can laugh about it now. I bought another used vct pulley so I had a matching set and it is all good now, even compression all 6 cylinders, 170 lbs, and the intake cam timing was even on both banks as well @ plus or minus -1 to 2 at idle, The best guess I have is in 2005 and early 2006 they used the one vct pulley which added the timing and gave 195 psi at cranking speed, and I'm just guessing here that sometime in 2007 they switched to the latest vct pulley which yields 170 psi and basically no cam advance at cranking speed, and my biigest guess is that when these powerheads were redone there was one motor with the old pulleys and one motor with the newer pulleys and the tech mixed them up??

Interesting, glad you got it figured out..