Loss of RPM on Tomatsu 90

[Davetreble]

I keep expiriencing a problem witrh loos of RPM on my 90HP Tomatsu Two stroke out board. the engine was fully service with all filters cleaned , new plugs etc. After atime when running at 4000 RPM plus I suddenly loose power. If I pump the fuel lift pump rubber bulb the RPM picks up. Could this be dirty fuel and should i fit aqn extra inline filter ?

 

[Bondo]

Re: Loss of RPM on Tomatsu 90

Ayuh,... Welcome Aboard,...

I'd suspect dirty fuel, or a failing fuelpump,....

 

[TOHATSU GURU]

Re: Loss of RPM on Tomatsu 90

It could be anything. Mechanical, electrical or fuel.

 

[pvanv]

Re: Loss of RPM on Tomatsu 90

I'm not familiar with that brand, but I have worked on some Tohatsu 90's... A weak fuel pump, or an air leak in the fuel suction line could be one cause of the issue... But Elvin is right, it could be almost anything... would need some more diagnostics to narrow it down.