Hi, I'm back, looking for more help. The short summary of the problem is the engine won't idle. If I throttle it up to about 1100 RPM it will sit there forever.
If I throttle it down to idle, once it is warm, it appears to be set right, it idles at 800 RPM but after maybe 10 seconds it will slow, slow, slow, quit.
If I throttle just a tiny bit above 1100 RPM it will go up a little and then it zooms up to 3000 or 3500.
Things I've done.
New impeller (I was in there)
New fuel filter
New spark plugs
Threw away 70 gallons of gas (most of it clear but the last 1/2 gallon or gallon was yellow and shellacy, I couldn't suck that out so I mixed it with 30 gallons of brand new premium, pulled the input hose off the fuel filter, pumped the bulb until the gas ran clear, but the hose back, ran the engine for 20 minutes to get an old gas out of the carb bowls, no joy).
New oil pump and got the oil pump working
New computer (didn't need that as it turned out)
Cleaned the fuel filter after it was getting clean gas
What I'm really looking for is a mechanic that knows these engines. I'm a semi decent home owner mechanic, I've fixed a lot of stuff, my impacts go up to 3/4", but my area is mostly stuff like tractors, excavators, skid steers. I'm way more diesel than gas. I have dealt with engines like this, I had a Honda 550 4 (or was it 500 4, I dunno) that had 4 carbs and I had to balance them, but that was decades and decades ago.
I don't just want a marine mechanic, I specifically want one who has fixed these larger Yamaha 2 strokers with carbs. Ideally one local to the Santa Cruz area.
Because I have to decide if I put expensive mechanic money into this engine or if I man up and repower to the tune of $13K for just the engine.
I'm kinda wondering about a vacuum leak. The engine runs just fine at speed, when I bought it we were in a harbor in Eureka, flat water, that engine pushed my 215 CC at 45MPH. So it's not junk (though Barry and I agree it's sort of a moot point, it's never gonna be that flat out on the ocean, if you can do 25, that's about as fast as you want to go).
Help me out with a pointer to a mechanic or a pointer to a forum that deals with yamaha engines pretty please!
If I throttle it down to idle, once it is warm, it appears to be set right, it idles at 800 RPM but after maybe 10 seconds it will slow, slow, slow, quit.
If I throttle just a tiny bit above 1100 RPM it will go up a little and then it zooms up to 3000 or 3500.
Things I've done.
New impeller (I was in there)
New fuel filter
New spark plugs
Threw away 70 gallons of gas (most of it clear but the last 1/2 gallon or gallon was yellow and shellacy, I couldn't suck that out so I mixed it with 30 gallons of brand new premium, pulled the input hose off the fuel filter, pumped the bulb until the gas ran clear, but the hose back, ran the engine for 20 minutes to get an old gas out of the carb bowls, no joy).
New oil pump and got the oil pump working
New computer (didn't need that as it turned out)
Cleaned the fuel filter after it was getting clean gas
What I'm really looking for is a mechanic that knows these engines. I'm a semi decent home owner mechanic, I've fixed a lot of stuff, my impacts go up to 3/4", but my area is mostly stuff like tractors, excavators, skid steers. I'm way more diesel than gas. I have dealt with engines like this, I had a Honda 550 4 (or was it 500 4, I dunno) that had 4 carbs and I had to balance them, but that was decades and decades ago.
I don't just want a marine mechanic, I specifically want one who has fixed these larger Yamaha 2 strokers with carbs. Ideally one local to the Santa Cruz area.
Because I have to decide if I put expensive mechanic money into this engine or if I man up and repower to the tune of $13K for just the engine.
I'm kinda wondering about a vacuum leak. The engine runs just fine at speed, when I bought it we were in a harbor in Eureka, flat water, that engine pushed my 215 CC at 45MPH. So it's not junk (though Barry and I agree it's sort of a moot point, it's never gonna be that flat out on the ocean, if you can do 25, that's about as fast as you want to go).
Help me out with a pointer to a mechanic or a pointer to a forum that deals with yamaha engines pretty please!