class6

Do a compression test to see if you're looking on the wrong side of the motor. Inside or outside

35fountain

They don't build them...Motors had a GM tag on them. Made for Merc

AllDodge

iTrader: (1)

Agree, but if there are any issues look out.

SB

iTrader: (1)

A few people back in the Speedwake days got pooched by them with new GM Marine 502's.

Side note; If I remember right, the GM Marine 502's don't come with the 30# oil bypass in the pad. Could be wrong, been a while, but it is putting a large red flag in my mind. Hopesomeone remembers better.

35fountain

ok,. i will pass this along to him..But, are you saying that there could be a compression issue in one cylinder and a valve seat problem which is causing this engine to miss, buck only at 4700 rpm's. Its max rpm is 5000. Wouldn't you think if this was the case it would show a sign of a miss, hesitation at lower rpms, better yet..6 people on the boat starting to get on plane, that to me is the most stress load on the engines and if there was a cylinder issue it would show something with that load on it. just my 2 cents

SB

iTrader: (1)

Again, get the 2 engines separated from each other electrically. Run, and see if just one engine has issues, then diagnose from there. This could remove 1/2 the possible issues .

class6

Like a broken valve spring would be noticed in the upper RPMs just before it totally fails. I'm not saying it is. It it's worth a look. And there's a chance you could pick this up on a compression test.

35fountain

ok...next run tomorrow..if it still does it we will remove covers and inspect the springs
thanks

underpsi68

Just my .02- if your problem is intermittent, when you hit the trim switch, it's not a broken spring, compression etc. Those problems would be all the time. IMO your problem is electrical related some how. Could be a bad ground, bad connection or a bad electrical component.

I wish I could help more.

Jonesyfxr

iTrader: (1)

I have read the entire thread, and there's tons of great info. The one thing nobody mentioned.....are there any ignition tethers on this boat? My friend just had an issue with one, after hitting a large wave during the Mentor Poker Run.