4.3 L OMC

My boat overheated due to a failure in the water pump. We shut it down, but it appeared to blow a head gasket. The heads were cleaned & inspected. I replaced the gasket but must have gotten the distributor in wrong because it backfired when I attempted to start it. I couldn't get it started so I took it in to a marine shop. I was told that I had bad compression in my #3 cylinder. I pulled the engine and was going to buy a short block. I took the heads off & oil pan, and it does not appear that any cylinders are scoured or damaged. The engine is only 2 years old (a remanufactured engine). At this point I am not sure what to do. Can an engine shop tell me if the block & piston, and rings are in good shape? Could a bad push rod be responsible? I mixed them up when I re-installed them. Can I do a compression check with the engine out of the boat? Any thoughts will be greatly appreciated.

Re: 4.3 L OMC

Bart,<br /><br />Doing the comp. check out of the boat is going to be tough. If your cyl. walls look good, I would bet you had/have a valve problem. You could have had a rocker tightened down to tight.

Re: 4.3 L OMC

Also you could have warped the head and therefor not getting a good seal.<br /><br />Craig

Re: 4.3 L OMC

I would check for crack or warped valve in cylinder with low compression put a straight edge on the head. Also if you already have head and pan off I would hone cylinders and put new rings on. When you put it back in Loosen all the valves until have a little slack on each in each valve on the compression stroke. Then check compression. if all good turn until cyl 1 is on compression stroke at top dead center and install dist pointed to cyl 1. Start it and let idel then adjust valves to correct setting but do it slowly and if it starts to miss back off and start over. Then I would retorque the head and do another compression check.

Re: 4.3 L OMC

Thanks for the suggestions. I will take a look at it over the weekend & post my progress.