2 stroke 50hp stalling

[moneypit]

A week or so ago I had an issue where gas was spitting from my bottom carburetor. The research I did told me that it was an issue with the float pin. So I opened her up and replaced the float needle, float, and all the other stuff that came with the kit. The boat ran perfect for two days (probably 2-3 hours). This morning it cranked up fine, idled fine, but when I got on the throttle it bogged down and stalled. After a few more tries with the same result I limped back to the ramp. It starts great, and revs up in neutral fine, but under load it stalls. Any help would be awesome. Thanks!!

[TownsendsFJR1300]

A week or so ago I had an issue where gas was spitting from my bottom carburetor. The research I did told me that it was an issue with the float pin. So I opened her up and replaced the float needle, float, and all the other stuff that came with the kit. The boat ran perfect for two days (probably 2-3 hours). This morning it cranked up fine, idled fine, but when I got on the throttle it bogged down and stalled. After a few more tries with the same result I limped back to the ramp. It starts great, and revs up in neutral fine, but under load it stalls. Any help would be awesome. Thanks!!

Pull the drain plugs at the bottom of your float bowls and try to catch what fuel and possible crap may have gathered in the float bowls.

Probably have some crap got dislodged and is clogging up the main jets..

[moneypit]

Pull the drain plugs at the bottom of your float bowls and try to catch what fuel and possible crap may have gathered in the float bowls.

Probably have some crap got dislodged and is clogging up the main jets..

Thanks! When I get a moment I will do that and report back. Of course it was the bottom/most difficult one I was messing with so it might take a bit more time. Thanks again for the input.

[TownsendsFJR1300]

Of course it'd be the hardest to get to! Wouldn't be "fun" if it wasn't!

Good luck.

[robert graham]

Thanks! When I get a moment I will do that and report back. Of course it was the bottom/most difficult one I was messing with so it might take a bit more time. Thanks again for the input.

Be sure to put a rag down there under that carb so if/when you drop that drain plug it doesn't get lost....

[TownsendsFJR1300]

Be sure to put a rag down there under that carb so if/when you drop that drain plug it doesn't get lost....

Hopefully if he can squeeze a can under there, it'd fall in there. With that said, if the can won't fit, some folded up aluminum foil will catch debris(for inspection) if nothing else fits. Good idea though!

[moneypit]

well, didn't really see anything to speak of when I drained it (no debris) and gas seemed to look good (no water). Should I take the carb apart and re clean it? Is there a good technique I should follow to make sure that I do a good job of cleaning so stuff doesn't clog the jets? Or any other ideas/opinions are welcome. Thanks in advance.

[TownsendsFJR1300]

Did you physically pull out the idle and main jets to inspect and clean?

You have to be able to see thru them.

Being the engine ran fine for several hours, it shouldn't have clogged up already..

The Yamaha under cowlfuel filter clean, no water, o-ring not pinched/missing?

Also, is the pick up filter in your fuel tank clean/clear?

[moneypit]

Did you physically pull out the idle and main jets to inspect and clean?

You have to be able to see thru them.

Being the engine ran fine for several hours, it shouldn't have clogged up already..

The Yamaha under cowlfuel filter clean, no water, o-ring not pinched/missing?

Also, is the pick up filter in your fuel tank clean/clear?

All I did today was take a look at the gas after removing the plug from the bowl. I will pull it completely off tomorrow and take a closer look at the inside stuff. I ran it again after looking at the gas and went to re drain the gas from the float bowl drain to take another look at the gas, but this time none came out. Even when I was priming the bulb. Not sure if this is normal or if this confirms that I am just gummed up?.?. And I appreciate the help, I am pretty close to just brining it in somewhere but $$$ is definitely a factor.

[99yam40]

If no fuel came out of the bowl drains even with pumping the primer bulb, you will have to take things apart

[TownsendsFJR1300]

If no fuel came out of the bowl drains even with pumping the primer bulb, you will have to take things apart

+1 ^^^


You should be able to pump thru and out of the carbs with the bowl drain plugs removed (pumping manually is like the fuel pump pumping up to the carbs.

You may want to start checking prior to the carbs, OR the floats in the carbs are sticking shut..

And once again, DID YOU PHYSICALLY REMOVE, INSPECT AND CLEAN THE JETS IF NECESSARY?? Were they clogged up? Please answer or we're running around in circles..

[rodbolt17]

takes maybe 2 hours to pull the carbs,clean them,clean the lines ,replace the fuel pump and reassemble.
typically the only gasket I need is the pump to block.

[moneypit]

Finally got around to taking the carb off. The jets were clogged with what was left of the small o ring for the float pin housing. It was supposed to be, but not in the rebuild kit. So I assumed it wasn't necessary. It looked ok when I changed everything the first time, but looking at it this time i noticed it was disintegrating. So i contacted the company and got a new one. After putting it in it runs like a champ. Thanks so much again for the help!! I really appreciate it.

[TownsendsFJR1300]

Excellent!

Just curious, did you pull the jets the first time, or just this time..(not judging, just curious).

BTW, Yamaha's "Ringfree" will help keep your carbs clean should you start using it, works, very, very well.

A good fuel stabilizer ("Gas Shok" works very well) is a must as well. Even if you run the engine dry, the little bit of fuel left in the bowls is enough to clog up those jets again...

[99yam40]

Finally got around to taking the carb off. The jets were clogged with what was left of the small o ring for the float pin housing. It was supposed to be, but not in the rebuild kit. So I assumed it wasn't necessary. It looked ok when I changed everything the first time, but looking at it this time i noticed it was disintegrating. So i contacted the company and got a new one. After putting it in it runs like a champ. Thanks so much again for the help!! I really appreciate it.

I really wonder why they do not include the o rings for the needle seats in the kits. I also had to order them separately for my C40.
It would make more sense to leave the floats out of the kit as they are not needed most of the time and include all of the gaskets, o rings,jets, needles and seats, but when did Yamaha make sense with what they do