99 C150 bogging issues at WOT

[99yam40]

How about hooking up a portable tank to run it next time.
That will tell you if the valve is the problem.

1.5 hrs away is a pain

[ThanksandGigem]

Im going to remove the anti siphon valve tomorrow. I'm rebuilding the carbs now they really weren't that dirty but i've at a minimum verified all jets are clear. some of the floats were way off like 2-3mm should i expect to have to make any adjustments to the jet settings after i put them back within spec (16mm)

[ThanksandGigem]

never mind I got everything finished. I'm pretty sure the problem was with the pumps i ran at idle and the fuel level at the filter stayed at the very top which is something that hasn't been happening i'm going o get down to clear lake and run it tomorrow to see how she does. Also after putting everything back together I started pup the motor and this is the first time atleast without running during the same day that i didn't have to rev in neutral to get it to start. Normally I have to do that just to get it started then after that I don't have to the rest of the day.

[TownsendsFJR1300]

Something to consider once your issue is fixed.

Run Yamaha's "RingFree" in your boat 100% of the time. Its a fuel and top end cleaner that works extremely well. I've used it at twice the recommended mix for stubborn engines (W/O) incident with good results:

https://www.shopyamaha.com/product/d...?b=Search&d=34



Also, especially if using ethanol fuel, use a fuel stabilizer. Ethanol fuel will go bad in as quickly as a month and clog up jets.

If your spark plugs haven't been changed in awhile, change them. I had similar running issues with my F150 and new plugs fixed my problem. (your issue doesn't sound like plugs but neither did mine).

[ThanksandGigem]

Something to consider once your issue is fixed.

Run Yamaha's "RingFree" in your boat 100% of the time. Its a fuel and top end cleaner that works extremely well. I've used it at twice the recommended mix for stubborn engines (W/O) incident with good results:

https://www.shopyamaha.com/product/d...?b=Search&d=34



Also, especially if using ethanol fuel, use a fuel stabilizer. Ethanol fuel will go bad in as quickly as a month and clog up jets.

If your spark plugs haven't been changed in awhile, change them. I had similar running issues with my F150 and new plugs fixed my problem. (your issue doesn't sound like plugs but neither did mine).

Thanks for the notes on the ring free I'm going to run some through next tank. I did replace the spark plugs first but no dice so I moved on to fuel.

Just got home from running the boat and it seems like all my woes are solved. We ran for 1.5-2 hours at wot 80% of the time out on lake Conroe. Turns out that's the closest body of water at just over an hour. The boat ran great I had a bit of trouble getting it started but I think I flooded it had a bit of a rough idle but once it warmed up it ran great. I personally believe the issue was the pumps just based on the difference in idle fuel level before and after the new pumps.

However, in total what I replaced was the whole fuel line tank to engine,the bulb, both pumps and rebuilt the carbs.

[TownsendsFJR1300]

Thanks for the update and glad you got it running correctly again..

Re the Ringfree, It does take a tank or two to see/feel any difference. If you run it very heavy (which sounds like you don't), it'll work quicker.

IE; I used it heavy in a 10 HP chipper/shredder (used maybe twice a year). It wouldn't idle and had a slight misfire at WOT (3,600 RPM's). It needed the choke partially on to keep running. Within an hour of running (I was shredding with it), it would idle down to normal and no more high RPM misfire (no choke either). I NEVER touched the carb, etc, just the RF...