Motor just rebuilt and still doesnt run right.

[Jugfisher]

I have a 70hp 1980 merc. I just had the power head rebuilt with all new pistons, valves bored, carbs rebuilt, etc. I got it back form the shop and the timing trigger had gone and burned up my #2 cylinder. i didnt know that was possible but it was under warrranty so i didnt care. I get it back from the shop the second time and then the power pack was bad in it. So he gave me a used powe pack to stick on it and that worked for about 30 min. and it started sputturing when it go over 1/4 throttle. I know I have good compression I know the carbs are clean and the plugs are firing in the right order. I was told while i was breaking the motor in I need to run double the oil in my gas. Could this be loading my plugs to where they may not be firing correctly? Or could all that oil (31.oz to 6gal ) be a factor.

 

[Laddies]

Re: Motor just rebuilt and still doesnt run right.

The oil mix is proper for break in, I probably am not telling you anything you don't know at this point but if you paid them to repair the engine and with the trouble you are having you went to the wrong repair shop

 

[Jugfisher]

Re: Motor just rebuilt and still doesnt run right.

Well the reason it has been giving so much trouble is b/c I got it so hot that it was able to melt the power pack. When the mechanic took it our for a test run it did ok and he was hoping that I wouldnt have to replace it. As hot as i got the engine it is no telling what all I have damaged. I have talked with a couple of people and for everything that I have replaced I was told that all it can be is fuel or fire. So I was wondering is all that oil (although I know it is necessary) fouling or loading my plugs to the point they will not fire? Am I going to have to keep changing or cleaning my plugs during all 10 Hours of the break in.

 

[Jugfisher]

Re: Motor just rebuilt and still doesnt run right.

Does anyone think that it could be a fuel pump problem?