I am having problems with the motor I have in my boat...its a rebuilt vortec 350 it now has about 12 hours on it now, well I lost rpms and it stalled now it won't start. I do a compression test since i have the tester for that..results not good!
1-140
2-15
3-140
4-140
5-20
7-140
8-40

obviously i have big problems..all the valves seem to go up and down so where should i start next...How can i troubleshoot this to find out excactly why i am losing compression in these cylinders on such a new motor!
-Harry

short of pulling the heads, you can do a leak down test wkich will tell you exactly where your problem is, as spread out as it is Id have to guess valve issues may be from water in fuel or running to lean


just a guess and my 2 cents

Maybe because its a seven cylinder
1-140
2-15
3-140
4-140
5-20
7-140
8-40

Could not help myself. .. Good luck

What is the carb and jets, what is the total timing, what fuel are you using, how old are the exhaust manifolds ?
Have to agree with GOODT

i got my numbers mixed up...I just found a blown head gasket already...it was burned out between 5-7 cuasing no compression there...I am still looking into the rest...why would it blow already...it has 12 hours on it

torqued incorrectly ??????or overheated


who rebuilt it ??????