Fuel Foul on 2

[Captcasey]

It is a 2000 Ultra. It has spark and 110 lbs of compression. Yet number 2 cylinder will fuel foul almost immedialty or within 20 seconds. Is it the carbs or is something goofy happening with the ignition? All ideas appreciated.

[FastUltra]

Re: Fuel Foul on 2

Are you premixing in the tank? Check to see if the oil pump calbe has broke or come off.

[Technical Support]

Re: Fuel Foul on 2

What plugs are you using?

[Captcasey]

Re: Fuel Foul on 2

I am currently premixing at 50 to 1 since I just had the engine out. I have the oil pump at wide open. By the way the manual says to keep 6mm clearance between the cam and the stop on the oil pump. Suggestions?... Also I am running the BR9eS.

[Technical Support]

Re: Fuel Foul on 2

What do you mean you 'have the oil pump at wide open'?? There is only ONE properly way to align it - read the tech article for procedures.

[Captcasey]

Re: Fuel Foul on 2

Just as it sounds. Wide open. As if the pump were in the wide open position. Which I understand it to be the oil pump cam against the stop when the throttle is wide open at the 12 oclock position on the pump. The owners manual states that there should be 6mm or .023 clearance between that stop and the cam at wide open throttle. Since the lines have recently been evacuated of oil I thought it wise to tie the oil pump in the wide open position while premixing. My question is why is number 2 cylinder fouling and the others are never fouling. It appears to be fuel. Could it be itermitant spark? Did the plug not fire as a result of an ignition problem and became fouled? Or is that carbuerator on 2 running as if the slide is stuck open allowing the high speed jet a constant flow overwhelming the plug. I am asking if anyone has seen anything like this?

[FastUltra]

Re: Fuel Foul on 2

Yep thats why. The premix is fine for just a tank. You should really only have to hold the pump wide open for only a minute or two. That will clear any air in the lines. Its really more important to bleed the pump through the bleeder screw then worry about the lines. That is why you are fouling the plug. Change the plugs let the pump work by itself and you should be fine.


The reason number 2 is fouling more is because it gets more oil then 1 and 3.

1 and 3 get a half line to their carbs, and then the oil from the front and rear ballancer gears splash over into the crankcases. So if you take the motor out, sometimes it takes an hour or so of running to reballance the level of oil in the ballancers. But don't worry about that.

[Captcasey]

Re: Fuel Foul on 2

Thanks again Paul. I would have assumed 2 got the same oil as 1 and 3 but there you go.. By the way I noticed NGK makes a plug (not the iridium) that has a groove in the electrode. What is you plug of choice?

[FastUltra]

Re: Fuel Foul on 2

on a stock 1200 engine the best bet is the BR9ES