trouble with 525 sc
 

had a push rod come out..all rockers were adjusted properly,push rod is not bent and no other damage done..what happened? this happen to anyone else??

something had to break ,take a closer look.was the poly lock still on the rocker stud?

Hows the cam lobe look

Yep .

Pressed in rocker stud pulling out?

Lost a cam lobe and/or collapsed a lifter or that single rocker arm came loose.

I would agree as others said lifter collapse or rocker loosen along with what does the cam lobe look like.

no bbc had a pressed in rocker stud to my knoledge.

yes poly lock was still in place..when removed i left set screw in original position and reassembled with 3/4 turn on lifter..collapsed lifter?? brand new crower rollers..
thought maybe something went through and held the exhaust valve open, but you think you would have seen damage in the blower..would like to test run the motor again but scared of breaking something..

In reference to that in red : huh ?

Like mild thunder said. That motor is a flat tappet and that is usually the sign of a bad lobe.

i loosened off the poly lock to reinstall the push rod..i kept the set screw in place without turning it and screwed back down to zero lash..then turned another 3/4 turn till it stopped..so i assume thats where it was set to originally..

no its a hydraulic roller

Well, there could be your answer. The Poly lock could have backed off.

Did you install these rocker arms because of a problem, or just because ?

If just because, then you did not tighten the set screw correctly to lock it down.
Would be too much of a coincidence too.

just rebuilt both motors with all new parts..

Sounds like the poly lock backed off. I usually adjust the valve lash, tighten the set screw. Then, I give the 5/8 nut and set screw a 'squeak' turning both of them at the same time. Don't get crazy on them, but don't be a little girl either.

Something else to consider. I have seen the tops of rocker studs in pizz poor shape. The part where the set screw mates up against. The top of the stud needs to be flat, the set screw just holds better.

thanks.. but like i said, the poly lock was still locked in place when i removed the valve cover..im thinking maybe a collapsed lifter..its all back together,and gonna run engine on land tomorrow and ifs all good will take out on water and try again..will let you know how it went..

i dont know what brand the lifters you used are but maybe one broke where the axel goes threw the body,i have seen that happen a couple of times but usually on lifters with a lot of hours on them.i recommend pulling the intake and checking before restarting the engine.

Are the set screws all at a similar depth in the poly lock? Usually a sign when one is way off. Maybe a lifter issue. I get what you're saying about the lock, you put it back exactly where it was and the lifter seemed to be preloaded properly.

they are new Crower lifters..thanks, i will pull the valve cover first and turn engine over to see if all valves are moving properly before starting..and yes all locks were at the same depth..

ran both engines today on land..checked timing, set idle, everything is A ok..gonna put in water tomorrow for test run, will let you know how it went..


took out boat today..within a couple of minutes under load pushrod popped out again!! these are both rebuilt engines with all new parts.. any suggestions would be appreciated.. i am leaning towards a bad lifter..