02 Tohatsu MFS 25 a Engine Problem

[Douglas57]

Took the inflatable out runs at low speed in gear ( Engine revies up out of gear ) However as soon as you put a load on it by giving more throttle, the motor sputters ( the warning light on engine is not on) Can't seem to find out what's causing it. I have changed Fuel, water seperation Filter, Fuel Filter oil & Oil filter. also had a mechanic check it out he clean all 3 carbs & Put it back together. He said it did not do it when he took out on lake, ran it for 20 minutes full throttle. I took out Sunday went a mile up river stopped at sand bar for 20 minutes with engine off and then headed back got half way and it did it again. With wide open throttle, you go nowhere it sputters. Any ideas as t what's causing this?

 

[pvanv]

Re: 02 Tohatsu MFS 25 a Engine Problem

Could be almost anything, but fuel system is often the problem. You need to properly diagnose the issue (with the aid of the Factory service manual) to fix it. What method was used to clean the carbs? Were they re-synchronized when reinstalled? Have the fuel connectors on the primer hose been replaced recently? Is the oil level too high? Does it run OK at mid throttle?

 

[Douglas57]

Re: 02 Tohatsu MFS 25 a Engine Problem

Captain Thank you for your response I greatly appreciate your time and expertise ! Oil was changed and when I checked last night it was at top of full level . I have taken to a marine mechanic 2 times says he cleaned all 3 carbs no other detail than that. when I got it back it ran great for 20 minutes I stopped & shut it down and waited another 20 minutes & headed back to boat and half way it started acting up again no warning light came on it just would not get out of its own way As far as fuel connectors I have not changed only changed fuel filter Water seperation filter mid throttle a little smother If I dont put a load on it I can rev up pritty high with out being in Gear when in gear and a load on prop Egine runs ruff but it got me back to main boat ? is where do I go from here

 

[TOHATSU GURU]

Re: 02 Tohatsu MFS 25 a Engine Problem

"Could be almost anything, but fuel system is often the problem."

The fuel system has to be gone through to see where the problem actually is. That is done by elimination of each possible item in the fuel system. Start with the fuel tank and work your way back to the reeds behind the carburetors.