90 horse mercury sportjet 1995 exhaust leak

shroom

Cadet
Joined
Jul 10, 2006
Messages
16
hi all, my regal rush which is powered by a 90 hrs mercury sportjet, with red stator, just replaced, boat is running good, but it makes a pop about every 7 seconds and a plume of exhaust escapes from under the flywheel thing with the stator inside of it... i took the top cover off and observed it is def coming from under there my question is is there some type of gasket or something that needs to be replaced the boat shop charges so much to work on this engine, and if its some i can do id like to know... please any help would be greatly appreciated, thank you
 

shroom

Cadet
Joined
Jul 10, 2006
Messages
16
Re: 90 horse mercury sportjet 1995 exhaust leak

come on , someone has to be familiar
 

Capt Ken

Commander
Joined
Jul 30, 2002
Messages
2,269
Re: 90 horse mercury sportjet 1995 exhaust leak

The only thing up there would be the upper crankshaft seal. If it was leaking, it could cause a lean mixture in the number one cylinder and cause the backfiring you are discribing. To change out the seal, you would need to remove the top bearing carrier which is not easy while the block is intact.
 

Zamboni

Petty Officer 2nd Class
Joined
Jan 29, 2005
Messages
151
Re: 90 horse mercury sportjet 1995 exhaust leak

Try to be more specific in describing the leak, "escapes from under the flywheel thing" leaves a lot of possibilities. You state the red stator was just replaced, removing the flywheel to swap out stator can be dificult-may have caused the problem. CAREFULLY (engine running) examine where the crank exits etc to pinpoint the leak source.....see if its crankcase seal.

PM me your email and I'll send you pdf shop manual, should help diagnose this.
 

Zamboni

Petty Officer 2nd Class
Joined
Jan 29, 2005
Messages
151
Re: 90 horse mercury sportjet 1995 exhaust leak

LOL....started writing my post before you posted Ken....took me 1 1/2 hours while dealing with getting kids ready for camp.

Probably is the upper seal, looking at shop manual it apears to go on after the cage assembly so he may be able to just remove cap/washer/nut and replace the seal.

Shop may have used heat to get the flywheel off to do the stator.
 

shroom

Cadet
Joined
Jul 10, 2006
Messages
16
Re: 90 horse mercury sportjet 1995 exhaust leak

i really appreciate it zamboni... i was hoping i could do this myself.
Zamboni said:
LOL....started writing my post before you posted Ken....took me 1 1/2 hours while dealing with getting kids ready for camp.

Probably is the upper seal, looking at shop manual it apears to go on after the cage assembly so he may be able to just remove cap/washer/nut and replace the seal.

Shop may have used heat to get the flywheel off to do the stator.
 
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