Mariner 8HP Problem

[duffm8hp]

Mariner 8M was running very well. But then it started cutting out, and then spewing fuel into the water. Replaced the valve, seat and float. Bulb pumped up hard - Don't think it was the problem.

Still seems to flood quickly. I eventually got it running but only on one cylinder. It has new plugs plus I can see both have spark using a timing light.

Searching I've found that this motor may have a suzuki power head.
I've read something about reed valves ? Anybody know anything about the Mariner 8HP ?

Duff

 

[Laddies]

Re: Mariner 8HP Problem

Thats not a reed problem but it could be a ruptured fuel pump diaphragm. The thing that don't make any sense is when you say the bulb pumps up hard thats impossible with a fuel leak on the engine have you misstated yourself?

 

[duffm8hp]

Re: Mariner 8HP Problem

Yes I agree - It does pump up hard. So I would assume that the float and valve is working OK.

I'll check on the pump diaphram & check valves again.

I finally found the model on a Mercury/Mariner parts site that shows
an exploded view of the parts. My Serial Number is 677 S 05068.
Not sure what year it is.

 

[duffm8hp]

Re: Mariner 8HP Problem

Just did a compression test - 100 each so that looks good .
Also found an on line a site that has an exploded view of the motor.
It's a magnito - points, condenser...etc .
Site also has a view of the carborator - mine is the second one in the list.

http://www.usboatsupply.com/Mercury_Mercruiser_Parts_Catalog3a.php?mc=02&ms=700& si=639

I'm thinking of replacing the fuel pump diaphrams and check valves, plus points and condensers.
Anybody got a trick to pull of the flywheel whitout buying the $200.00 tool
Also your thoughts on replacing other parts.

Thanks

Duff

 

[frednick1]

Re: Mariner 8HP Problem

I have a Mariner 8HP. Mine did a similar thing and I found that the primer/choke diaphragm was perforated. Be careful when you replace it. There is an optimum way to replace that part. Also there is a tiny check ball in the device that will fall out if you are not careful. Take some pictures of the layers of rubber that you remove so you can get it to go back together right. It took me 4 tries to get it right. Frednick1