URGENT help needed 1978 9.8 merc

[jono_uk]

ill start at the beggining i got a 9.8 merc 2nd hand in a bit of a state it wouldnt start seemed to have good compression on pull start i replaced the switch box and had her running so i decided to give her a new lease of life and repaint it. i removed the carb off the block and took the block out i have not took the block apart only removed the carb from it and replaced the spark plugs with the same ones i removed for new ones. repainted block and put it all back together. i cannot get it started and have tried numourous times i have changed the carb but still seem not to be getting any fuel to the plugs and for some reason the engine seems to have lost a load of compression on pull start it is easy to pull over where before it was tight to pull over i have put a compression tester on it and after 3 pulls it read 90psi on each cylinder i am at my witt ends with this so if anyone got any ideas i would be gratefull if you could reply as i really want to get moving on the river

 

[8075mercury]

Re: URGENT help needed 1978 9.8 merc

Very perplexing!

I do not know why the compression dropped. Maybe it did not change at all if you did not check with gauge before and after?

One thought, I think there is a small hole on the carburator flange that allows crankcase pressure to actuvate the fuel diaphram and so pump fuel. You might check to see if this small hole got plugged with paint? I am assuming that you are still getting spark? Good luck, these are great little motors.

 

[jono_uk]

Re: URGENT help needed 1978 9.8 merc

i checked the hole on the flange all looks ok i never painted the flange but the pullstart when pulled seems a lot less pressure than before would the exhaust gasket cause anything like this??