Need help with 1978 Mercury 90 HP

jonndena

Seaman Apprentice
Joined
Jul 19, 2009
Messages
30
I got gas and spark but it won't even think about starting. Is there something deeper i am missing? It is a 6 cylinder 1978 90 HP Mercury and has all ways run perfect. Any help would be great.
 

swordfish25

Petty Officer 2nd Class
Joined
Mar 18, 2009
Messages
117
Re: Need help with 1978 Mercury 90 HP

I would start out with a compression check. If that is good, try new plugs and check the timming. Do the plugs look wet or dry? if they are dry, Maybe the eletc. choke is not comming on.
 

jonndena

Seaman Apprentice
Joined
Jul 19, 2009
Messages
30
Re: Need help with 1978 Mercury 90 HP

Its got new plugs and the plugs are wet. I am wondering about the timing also but i don't even get a little backfire or anything. Gas and spark most of the time causes some sort of bang, this ones got me a bit stumped. :eek:
 

P 0 P E Y E

Chief Petty Officer
Joined
Jun 3, 2009
Messages
441
Re: Need help with 1978 Mercury 90 HP

Plugs are wet with gas? or water?

Check your fuel for water

Check your combustion chambers for water

Does the engine sound different when cranking?

Look at he spark advance, see if it moves when you move the throttle

Clean off the plugs and try it again
 
Top