1999 C40 fuel enrichment washer fix

[dwilkin3]

Howdy all,

I've seen mentioned somewhere on here before where people have mentioned that there was a bulletin put out for a "fix" for the 3 cylinder two stroke outboards for the fuel enrichment plunger. They mentioned the "fix" was an OMC drain plug washer to be placed under the plunger for the enrichment mechanism, i'm presuming to induce a longer choked period prior to the expanding wax powered plunger closing the enrichment lines. Does anyone have any experience with this or know what the part number was of the washer? My 1999 C40TLRX sometimes won't stay started off the first attempt, i.e.- stalls once, then on the second attempt will stay running. I would suspect the carbs, except i have cleaned them all three times over including a couple runs in an ultrasonic cleaner. Compression is spot on at 120 psi on all 3 cylinders, and all ignition components check out utilizing peak voltage readings. Any insight would be greatly appreciated. Thanks.

-Daniel

[boscoe99]

Who put the bulletin out? Don't think it would be Yamaha if use of an OMC washer is called out.

Would be a simple enough matter to take the existing gasket to Grainger, Fastenal, NAPA or other autoparts store to see what other gasket could be added to the existing one. Or maybe try and find a scrapped Primestart device and use the spacer from it.

Unfortunately, Yamaha does not specify what the retracted height of the pin should be. That I know of anyway. Hard to determine if yours is extended more than normal in the cold position without comparing it to a brand new one.

On some of the Primestart devices you could carefully crack the thread locker and then screw the body away from the mount so as to increase the distance of the tip of the pin. Not sure if you can do this on yours or not.

Finally, if the motor is running lean (no surprise there) have you tweaked the idle mixture screws to make it run a bit richer at idle? Are you using straight gasoline or gasoline contaminated with ethanol?

Another option might be to change the size of the idle mixture jets a tad.