(the video shows the drop in level twice, I’ve seen it drop even lower than what the video shows as well)
C60TLRV Yamaha 60hp 2 stroke. Ok guys, this is something that has been going on for awhile. At WOT the motor bogs after about 10sec like it’s not getting fuel. If I back it down a touch it catches back in and keeps going. Then it got worse. I thought I isolated it to one of the fuel tanks with a so-so fitting but then it started with the other one (I have two 6gal tanks). Then I thought it was the fuel line (see prior post) and changed all this out. I checked the carbs and they’re clean. Still does it. Then I was watching the filter that sits right on the side of the motor while it was running. Every so often it seemed like the fuel level in it would go way down like it had a bunch of air it sucked in, or perhaps herky jerky flow of the fuel. I think I am going to change the rubber in the fuel pump next but was wondering if this up-and-down of the fuel in the filter is normal? I can imagine that at WOT there might not be enough flow during one of those low times thereby causing it to bog? Thanks for opinions.
been tryin to diagnose the same prob with my merc 150 for 2 summers now. had it in the shop for a bit and they were no more successful than i was. my guess is ethanol related. gonna change the lines between my carbs this spring and see what happens. everything else has been replaced line n fittings wise.
i have seen this same problem with a 70 2 stroke a while ago. You said you have plastic 6 gallon fuel tanks right? Check where the fitting screws into the pickup on the tank. i have seen some of the pickups not drilled out all the way at the little plastic fitting on the tank. im talking about where the brass fitting screws onto the plastic fitting on the fuel tank. its a 90 degree turn and ive seen them not drilled out all the way. it you said it was happening on one fuel tank and not the other i would check that. Is it a moeller tank? i think thats the ones that gave me trouble a while back.
While growing up, when my brother and i would have trouble with our older cars, 70’ GTO or 70’ SS Camaro, mom would say, “just sell the ■■■■ thing” (we always fixed em) Not a suggestion, just an anecdote. I wish you well fixing the issue. Good Luck. PS, not makin fun, been there, done that and you will fix it.
GW 232GT Gulfstream
150Yam x 2
“3rd Day”
Gen. Chap.1 Vs.9-13
I watched teh video, and looks to me like the needle may be sticking in a carb, and until the bowl gets very low, the needle doesnt open. when the fuel in the bowl drops to a certain level, then it opens, and the fuel pump dumps fuel into the carb, and needle closes again. that would be where I would start.
also, with the breather off the carbs, I would run the motor WOT, and when it bogs, give it a shot fuel into each carb, and see which cylinder bogs, and which one picks up
fishbrains, Sounds like Chris is on to something. If you want a second opinion try putting your post on iboats.com They have a yami section and if your lucky Rodbolt will reply. Good luck.
84’ 18 Privateer
08’ Yamaha 90
There are always greater fish than you have caught, always the lure of greater task and achievement, always the inspiration to seek, to endure, to find.
Thank you guys for the suggestions. I wound up changing the tank fitting which always seemed a little loose to me. It fixed everything. Here’s the pictures of the two different fittings. The old one is probably one of those supercenter bought ones that I purchased years ago. The new one is one of those high-dolla yamma orginal parts. Note the rubber seal in the new one - I think it made a big difference in not letting the air into the system that I think was the culprit.
