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5 hp 2 stroke tohatsu fuel pump problem

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bob0948

New member
"I have an early 90's 5hp

"I have an early 90's 5hp 2 stroke tohatsu, cannot get fuel to carberator bowl. I have cleaned and rebuilt the carb. I have changed the rubber goods in the fuel pump. I have cleaned the internal tank and cleaned the filter in the tank. I have good flow from the tank to the pump.

I put a fuel bulb in the line from the tank to the pump and can squeeze fuel to the bowl. Engine runs good, even under load until the bowl goes dry.

All of the orifices, holes and channels in the carb system flow air easily. I have tanken the fuel pump off and can blow through the pump easily. When I apply a vacuum to the pump inlet it closes as it should.

What have I missed that will not allow the fuel to enter the carb bowl?

I have cleaned the carb several times.

I am at a loss."
 
"Thanks for response. The ree

"Thanks for response. The reeds still have memory, return to proper position when lightly pressed open. Reed surfaces are smooth and the body seat is clean and smooth. What should the compression read? There is nothing in the owners manual that gives what the compression should be. Is there a range?

I checked the orfice that goes from the combustion chamber to the mounting face for the carb and it is clear, no restrictions."
 
"Repair and service informatio

"Repair and service information is found in your service manual, not an owners manual. It should be at 78 PSI.

If you have compression and the reeds are okay then you need to go back to your fuel system and see what you have missed."
 
"Tohatsu Guru, thanks for your

"Tohatsu Guru, thanks for your information. I found the problem. When I had the carb off I cranked the engine to make sure I good air flow and suction from the combustion chamber, in both the upstroke and downstroke. The flow was good. What I did notice is the last time I put the gasket on, I covered the suction hole and that was why I could not get the fuel pump to work. With the gasket put on the correct way the pump works fine. All I need to do now is adjust the carb for the correct flow. I believe the proper procedure is to first seat the adjusting screw, then back it out 1 1/2 turns and tune from there by adjusting 1/8 turn at a time until the proper flow is achieved. Again, thanks for the assistance."
 
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