Gas guzzlin m40d2

[secretary of the marsh]

I have a 2005 Tohatsu m40d2 that has recently been sucking gas way more than usual. It's on an old 1648 jon set up light. I bought the motor new, broke it in per spec, maintained perfectly, run a tiny tach so I know the R's, and haven't done anything different in the last 2 weeks it;s been acting this way. It runs perfect, as always. There is no change what-so-ever anywhere in the rpm range-power dept. I ran it on muffs today in the driveway with cowl off,and couldn't find a drop of gas from the tank to the motor or anywhere on the motor. There is absolutely no sign of fuel leakage anywhere, and I seem to be going through 2.5 times more fuel than usual. Any ideas? Thanks

 

[steelespike]

Re: Gas guzzlin m40d2

I can't speak for the Tohatsu but if the fuel pump diaphram developpes a hole
gas will leak into the crankcase. One plug may appear more fouled than the other.

 

[TOHATSU GURU]

Re: Gas guzzlin m40d2

The fuel has to be going somewhere. If it is making it to the carburetors without a leak then it has to be pooling back at the plugs. I would suggest you take it into a dealer and have them diagnose the problem. Your engine is only 3 to 4 years old and you don't want to start screwing around with it and make the situation worse.

 

[secretary of the marsh]

Re: Gas guzzlin m40d2

The fuel has to be going somewhere. If it is making it to the carburetors without a leak then it has to be pooling back at the plugs. I would suggest you take it into a dealer and have them diagnose the problem. Your engine is only 3 to 4 years old and you don't want to start screwing around with it and make the situation worse.

Guru................. Question... How can my motor run perfect if too much fuel is at the plugs???? There is more carbon on the plugs, but, the colors good on the electrodes on all three. Of course the top cylinder is a touch hotter.

 

[TOHATSU GURU]

Re: Gas guzzlin m40d2

It wouldn't. I'm discounting the amount of fuel usage that you think has increased I believe you about the increase... I just don't think it is as much as you think it is. You would literally be gushing fuel somewhere as you are talking almost an extra gallon per hour of fuel at WOT. Chances are you have a leak or one of the carbs is dripping fuel due to being gummed up. Normally you would see a degradation in performance, but, each case is different and sometimes what an engine should do is not what they end up doing. I really would suggest taking it into a dealer and letting them take a look at it As a WAG I think they will come up with run of the mill dirty carb syndrome. Or you could have something freaky like a fuel leak into the exhaust or an interment ignition failure.