1988 Gamefisher 7.5 hp - splits unburned fuel

[nld09]

Anyone knows what could be the problem? It pollutes water quickly with unburned fuel.

Thanks,

NLD

 

[Barnacle_Bill]

Re: 1988 Gamefisher 7.5 hp - splits unburned fuel

Check for a strong spark at both plugs.

 

[nld09]

Re: 1988 Gamefisher 7.5 hp - splits unburned fuel

I recently cleaned the Carb and put in new spark plugs. Maybe I messed the carb up.

 

[nld09]

Re: 1988 Gamefisher 7.5 hp - splits unburned fuel

I think I need to play around with the carb idle adjustment.

 

[k31shooter]

Re: 1988 Gamefisher 7.5 hp - splits unburned fuel

Are you sure that it is Gas? It looks to me that it might be lower unit oil? Maybe a bad gasket?

 

[nld09]

Re: 1988 Gamefisher 7.5 hp - splits unburned fuel

I smell/felt gas from it. It is not 100% raw fuel/oil mix. I am new to outboard engine, so I don't could be the problem. I am going to clean the water and run it again tomorrow to see what happens. Kinda afraid to take it to the lake.

 

[cvtech1]

Re: 1988 Gamefisher 7.5 hp - splits unburned fuel

I am not sure of the exact number but something like 30% of fuel is unburned and enters the water in a 2 stroke, so you will smell fuel. I agree with the the previous post it seems like LU oil. Check your seals.

 

[cantcatchsquat]

Re: 1988 Gamefisher 7.5 hp - splits unburned fuel

i have the same motor but a 1985 7.5 gamefisher and also have the same problem, does anyone know where i could get an owners manual for this motor?

thanks pat

 

[nld09]

Re: 1988 Gamefisher 7.5 hp - splits unburned fuel

cvtech1 - thanks for the reply. Do you know which seals should I take a look at?

cantcatchsquat - let me know if you got a solution for it.

I will probably take it to a lake over this weekend and run it full throttle to see if it will make any different.

I am thinking of getting a new Briggs and Stratton 5HP air cool (~$700) or a Tohatsu 6hp (~$1300).

Thanks,

NLD09

 

[asdasc]

Re: 1988 Gamefisher 7.5 hp - splits unburned fuel

Two strokes that are run in a barrel make a mess. It is amazing how much unburned oil there is in a poorly tuned motor. Even well tuned at idle will make a mess. At 3/4 throttle they run much cleaner, but NEVER run above 15% throttle in a barrel for any length of time more than a few seconds, as the whole cooling system is not designed for it. Use the barrel mostly just to see if it runs, then put it on a boat and in a lake.

I would do a pressure test on the lower unit prior to putting it in the water to make sure you aren't leaking there. Pull the plugs, drain it then hook up a pressure tester, pump it up to about 12 lbs and it should stay there for more than 15-20 minutes. Then do the same test with about 6 lbs of vaccuum.

Good luck,

 

[hunterope]

Re: 1988 Gamefisher 7.5 hp - splits unburned fuel

That sure looks like Lower Unit oil to me. The above posts are right about making a mess in the bucket. They all do it.. Also, your exhaust will produce a gassy smell in the water as well as some of the unburned gas. I think you need to look at the lower unit first. Just my 2cents. Good luck.

 

[nld09]

Re: 1988 Gamefisher 7.5 hp - splits unburned fuel

Thanks guys for the suggestions. I am going to play around with it (need to learn on how to do pressure test).

NLD09

 

[cvtech1]

Re: 1988 Gamefisher 7.5 hp - splits unburned fuel

They have special tester just for that. Do a little research and you can find one. There is a lot of good info on here just wait and you will get an answer. Good luck. I have a 1977 7.5 Gamefisher I just got and will be testing it hopefully this weekend.

 

[nld09]

Re: 1988 Gamefisher 7.5 hp - splits unburned fuel

I decided to disassemble the lower unit today to troubleshoot the problem. I didn't find any problems with the gear lube at all. Everything was in good shape. Unburned fuel was the problem. I fell much better now and will head to a lake this weekend . Hope would help anyone got this similar problem.

 

[cvtech1]

Re: 1988 Gamefisher 7.5 hp - splits unburned fuel

Great photo's, they sure will help me when I get to that point. Thanks, that what makes this a great site.

 

[Tom @ Buzzard Bluff]

Re: 1988 Gamefisher 7.5 hp - splits unburned fuel

I decided to disassemble the lower unit today to troubleshoot the problem. I didn't find any problems with the gear lube at all. Everything was in good shape. Unburned fuel was the problem. I fell much better now and will head to a lake this weekend . Hope would help anyone got this similar problem.

Glad to hear it! I think when running in extremely cold water (as most lakes are this time of year!) that the cold water keeps the exhaust leg chilled to the point that it condenses waste oil from the exhaust onto the inside surfaces of the exhaust housing. In warmer weather the condensation isn't nearly so significant a factor and the gunky looking oil weeping from internal passages is so minimal that it goes un-noted if it happens at all. Check it in the Summer to see if it has gone away. Cheers, Tom @ Buzzard Bluff

 

[hoglahyou]

Re: 1988 Gamefisher 7.5 hp - splits unburned fuel

To cantcatchsquats post, look online at sears parts direct and enter the model number of the motor. This should usually get you to the owners manual.

 

[seamorewaterVIP]

Re: 1988 Gamefisher 7.5 hp - splits unburned fuel

Are you sure that it is Gas? It looks to me that it might be lower unit oil? Maybe a bad gasket?

I am thinking the same thing. What ever is oozing out the sid is causing the problem find out where it is coming from.. I have a 68 game fisher that did the same thing and later figured out that it was a bad gasket sealing the lower unit. Check the gear oil in the lower unit and see if it is white and foamy or mabe even low. if you just put an impeller in it and did not replace the gaskets one of them may be cracked or pinched.

lol at my self run it in the lake before you spend too much time messing with the carb or adjust it at the lake

 

[asdasc]

Re: 1988 Gamefisher 7.5 hp - splits unburned fuel

Great pictures, but I wanted to clarify one of your lables. That tube you labeled as a route for unburned fuel to get exhausted thru the water jacket is actually the water pump output which feeds water up into your powerhead. Water flows up that tube, thru the powerhead, and then drains back down thru the whole leg.