Update on problems....
My OEM carb kits came in yesterday, and I got them both torn down, completely cleaned, and "rebuilt." Needles, gaskets, and mostly air side things came in the kits. I put them and the new OEM fuel pump on this afternoon after the guys left the shop. Got the carbs synched per the instructions on the DVD that I ordered that Cray recommended (thanks Cray) set the Pilot screws at 3/4 turn out and fired it up. It maybe ran slightly better than it did before my last issue started, but it still smoked way too much, just like normal. With the new gaskets and new crush washers on the ports, I knew that no air was leaking by anywhere and that the only air entering the fuel mix was coming from the Pilot screws. The factory range for the Pilot screws on my carb is 5/8 of a turn out +/- 1/4 turn. I figured by setting them at 3/4 turn I'd be more lean than I needed to be, but judging by the smoke cloud, it wasn't running lean...
So I turned the screws out another quarter turn. Nothing. Another half turn, it started to load up and stumble. ????? So I screwed the pilot screws until they were seated, then turned them out to my best estimate of 5/8 a round. The motor cleared up, the smoke cleared up and the RPM's increased. Turning the pilot screws in, was leaning up the mixture. I played around with some micro adjustments and have them now set at right at 1/2 turn out from fully seated.
I know I shouldn't make assumptions but I'm assuming that on a 2 stroke Yamaha that the tighter the Pilot screws are set, the more vacuum the air is pulling. That's really all that makes sense, so it almost has to be correct.
This is my first Yamaha and at best I'm a shade tree boat mechanic, but this air mixture and running rich has had me buffaloed for about a year. I feel like I reached a major milestone today. LOL I haven't taken it to the river yet, but I have no doubt it's going to run good. I'll be sure to pull my plugs after my first river run to make sure I'm not too lean on the mixture.
And no I didn't get hurt, or nearly killed, or hurt anybody else, or start bleeding which is very unusual when I'm working on something, and my boat runs good so I am happy.
Hope that fixes it for good! You will have to go tomorrow evening just to make sure it’s ready to go for Saturday! Lol
FurFlyin LIKED above post
One lower unit was enough. Give it time to clear up some. The river will still be there.
Proud Member of Team Geezer
Charlie Weaver USN/ENC 1965-1979
Slabprowler, crappiemax LIKED above post