Switching out OEM fuel pump for a Mikuni aftermarket on an 89 Force 85hp

[7501sl]

For some time Ive been thinking of rebuilding my OEM fuel pump due to age. The only thing Ive done to it is clean out the filter since Ive owned it (2 years). I came across this youtube video about switching out the single output oem fuel pump to a three output mikuni fuel pump to feed each carb independently. In the past Ive used this particular Mikuni fuel pump to replace an OEM fuel pump on a Polaris pwc and it was a simple enough task to complete. As I recall this Mikuni puts out 35 liters/hour. Seems like a good idea. Any thoughts or should i just rebuild the OEM? Thanks for the input.



http://www.youtube.com/watch?v=nxm5-YCN66Q

 

[Frank Acampora]

Re: Switching out OEM fuel pump for a Mikuni aftermarket on an 89 Force 85hp

It's nice to have the Mikuni with three separate supplies, but a new diaphragm for your pump will cost 3 bucks and a new gasket will cost 1.50. I don't know what button valves cost, but I have never had one go bad.So, it is going to cost you less than 5 bucks to "rebuild" your existing pump and it can supply well more fuel than the engine needs.

If your current pump goes bad, all three carbs dry up and the engine stops. If only one supply on the Mikuni fails. the other two pistons continue to run the engine and the lean running piston detonates and melts.

Is there an advantage to the Mikuni? Everyone will have a different opinion, but personally, I would consider it a waste of money.

 

[roverfj1200]

Re: Switching out OEM fuel pump for a Mikuni aftermarket on an 89 Force 85hp

I run a small inline pump to assist the the fuel delivery on my 120 Chrysler. I do run a long fuel line and the pump primes the motor when cold.

Cheers.

 

[7501sl]

Re: Switching out OEM fuel pump for a Mikuni aftermarket on an 89 Force 85hp

View attachment 87444

If your current pump goes bad, all three carbs dry up and the engine stops. If only one supply on the Mikuni fails. the other two pistons continue to run the engine and the lean running piston detonates and melts.

Good point. I'll just go ahead and rebuild the OEM fuel pump. I believe its parts #15 and #16 of the attached diagram. Btw the button valves are $4.27. Anyway thanks for your help.

 

[scottstaff]

Re: Switching out OEM fuel pump for a Mikuni aftermarket on an 89 Force 85hp

I run a small inline pump to assist the the fuel delivery on my 120 Chrysler. I do run a long fuel line and the pump primes the motor when cold.

I rebuilt my 120hp Chrysler fuel pump, but it still doesn't seem to pump enough fuel. What kind of inline pump did you install? (model, gph, etc) Do you run it only when starting up, or do you keep it on whenever the motor is running?

Thanks.