I uaslly put a new plug in at the start of the year. But my quad(Modds listed below) started to stutter and bog until it just quit when running water holes about 6" to 1 foot deep. I changed plugs and bad its good again. Ive done this every time out this year and only get 2 or 3 days on a plug. I've tried NGK BR8ES, B8ES, resistor, nonresistor, solid tip, gapped at .028 and it doesnt seem to change. How often do you guys change plugs with your race motors, is it the water holes? Running out of answers any help would be great.

 

I'd say it's something other than the plug, like jetting or improper oil mixture. I run alky through mine and then purge it out with an extremely rich mixture of race gas and I run months on the same plug!

 

I run 40:1 mixture Redline Synthetic oil and 25% Sunoco Race gas. Its a little rich but how does that contribute to plug problems?

After all that typing only 1 reply, come on guys.

 

You didn't say what the plug looks like after you take it out Scrammy. But it sounds like you are fouling your plugs. Were you running the same oil before the mods. If not, try a different oil. It sounds like a oil or jetting problem. I don't have the race mod so I'm sorry I can't be more help.

 

I have a ported 400, not a race motor but I can tell you I used to ride at a place with a shallow creek. I noticed when I would ride in the creek sometimes and the water would only be 6 to 8 inches deep my motor would cut out. It wasn't that I was soaking my plug wire or anything because I would be riding very slowly thru the creek when this usually happened.
The only thing getting wet that had any wiring going to it was the front hubs but I don't see how that could cause mis-fires. I don't ride there any longer or anywhere with water now and my plugs last me an entire year. I don't know what to tell you. I always swore the shallow water was causing mis-fires somehow but I would have no clue how that could be.

 

could be beacuse u ride at low rpms

 

i would check for a electrical wire wear-out,that can cauze an
drop of cicuit then igition is shut off,i don't known,what is the pilot jet in this carb?