another 8.0 problem

[darein40]

ok so far if its not one thing its another. ok here is the problem i just replaced the engine bearings and was running it not hard half throttle and it quits. broken connecting rod. what i would like to know before i fix it ..what would cause this? what should i be looking for?

 

[Snook Man]

1st thing I would check was if the piston was installed correctly after you installed the bearings.
If the cut out portion of the piston skirt does not face the front of the engine the piston skirt can hit the backplate chipping the skirt, then the schrapnel can get beteen the top of the piston and the head or in a sleeve port or under the con rod groove in the crankcase and cause major damage.

Hows the piston skirt look?

 

[darein40]

the piston skirt is damaged also. i know i put it back together right. i took a picture so i would not put it in wrong. the grooved side was facing the crank.

 

[srusinek]

That motor does run hot and it's possible that you might of ran it too lean my mistake. I have the MGT 8.0 and that thing does not like to be under 250 or so. The cheapest way you can go to replace the entire engine is to go through associated and do their trade in program.

 

[darein40]

ok i found that the rubber boot that goes between the header and muffler had split. could this cause the connecting rod problem..going way to lean.

 

[Phins Fan]

An airleak like that could cause you to run lean but thats a condition that you should have been able to pick up on when running.

 

[battyone]

ok i found that the rubber boot that goes between the header and muffler had split. could this cause the connecting rod problem..going way to lean.

I had this issue just a couple days ago too engine was revving out of charachter so replaced silicone sleeve and also the one at the cylinder port as it was a bit fried as well. Reset hsn and all is well again.