120 hp, old fuel in engine???

[daveywonder]

this 120 sat for 2 yrs., but ran before the last owner put her up. she will crank, but won't actually start..skidad had me put fuel in the four cylin.,and she did start and ran 3 sec....however the new fuel i have been squeezing in with the old bulb, is there still old fuel i need to get out before she will stay running? how is this done? motor is in pristine shape, i mean real clean. so give me some steps i can take to get rid of the old fuel throughout the motor. i'am a four-time boat owner, but never had to start from scratch to get one going.....tks.for advice..daveywonder..

 

[HotTommy]

Davey,
It would help if you were a little more specific about the year and model engine. .... If you can get it to run for a few seconds it should start to replace the old fuel. But I suspect the problem is more than old gas. It is likely that your carbs are clogged with deposits left by the old gas, and new gas won't likely fix that.

Replacing the old gas is messy and can be hazardous due to spilled gasoline. But here's how I would do it on my engine. I'd disconnect the fuel lines closest to the carb, place the line in a catch can and pump some through using the bulb. To get the gas out of the carb bowls, I'd loosen the screw on each bowl and let the gas drain out into a catch. When everything is buttoned back up, I'd prime it again, check for leaks and see it it will run. If yours won't run well after replacing the gas, you'll likely need to remove and thoroughly clean the carbs.

 

[Frank Acampora]

Davey: Just yesterday I took out my little go-fast with a 140. I had much the same problem--It sat for two years without running. The gas smelled normal, not like turpentine so I added fresh fuel to the tank. It was 12 gallons fresh to six gallons old. The engine started and ran but would stall unless I kept pushing in the choke.This meant that the high speed jets were OK but the low speed jets were clogged. Now, I had some other tests I wanted to run so I got her out onto the river and throttled up to above half throttle where the high speed jets kick in and did the boat tests.

HOWEVER: Since low speed jets deliver fuel constantly, even at full throttle, there is a very real danger of melting pistons so I did not run much above half and only ran sufficient time to test the hull and prop combination.

Since it is very likely that you have at least partially clogged carbs, it is mandatory that you remove the carbs, disassemble them, and clean them. WD40 and small pipe cleaners do very well. This is not a big job. The carbs are easy to get at and dirt simple so don't be afraid.

Again, if the gas smells like turpentine it should be replaced. If it has a typical gasoline smell, it is probably good to use but if you feel like replacing it -- couldn't hurt.

 

[jerryjerry05]

It's a 120, the float bowls on the carbs are easy to remove.
Take em off and see if there is any crud in the bowl.
Crud?? Then a cleaning is needed.
While they are off, check the reeds.
While working on it do a fuel pump rebuild.
Easy, just a gasket and a diaphragm.

 

[daveywonder]

tks...i;ll try your suggestions...pretty simple it seems.....let you know soon...