Hi All,

As some of you may know, I have been having some trouble with my Mach Z. *For those of you who don't know, basically I have been fouling a lot of plugs (mainly in the center cylinder), and there was a bit of a skip when going over bumps and sharp corners.

Anyway, I took it to the shop and they were able to fix the skipping problem 100% (although I haven't ridden it yet to see). *They said it was caused by a bunch of bare wires underneath the motor (see my post "What do you think is wrong" for more info on this). *

The problem is that it didn't solve the spark plug fouling problem. *It appeared to at first, but they took it out later on yesterday and blew two plugs in the center cylinder. *Anyway, the shop owner talked to another guy that had a Mach and he said that he runs BR8ES plugs in the center cylinder. *He also talked to a mechanic from Al's Snowmobile Parts Warehouse (some of you may recognize that place), and that guy also said to run an "8" in the center cylinder.

So he put a new BR8ES plug in the center and they took it for a ride. *They put on 60 miles with that plug and it never fouled.

I have heard a lot of people say not to change the heat range of the plug that you are using....what do you think about this case? *

Also, I should point out that the temperature yesterday was in the mid 40's. *Maybe that had something to do with it also.

Thanks for the help.

-Josh

Its the mild temps. *It leaves moist air in the combustion chamber causing the plugs to short. *Also all the carb adjustments are out of wack. *

It happened to me in my 600 twin 500 twin 700 twin and my Mach this year. *But it cooled of last week and it didnt happen once. *

Try going to bosch copper plugs also called SUPER BOSCH. *They seem to resist this problem better then NGK and SPLITFIRE. *You can try a hotter plug but i dont think thats your problem. *

Make sure your coolent isnt down because that will cause this type of problem. *Or even a bad plug wire.

Thanks Man....All of the plug wires were changed. *I will check on the coolant as well.

Do you think running the "8" in there will hurt anything? *

Thanks again.

-Josh

Running 8s wont do anything because its a liquid cooled machine. *You have a mach Z so you have the temp gauge so just watch that. *But i would be a little cautious about making full throttle lake crossings. *

But like I said stick with the 9s. *You can try the 8s but i dont think thats your problem. *I had 10s in mine and they lasted as long as the 9s.

Try the super bosch plugs. *I got them because i was fed up with the ngks fouling and they have been solid for 2 weeks. *

Your not alone. *Many people are having this problem this year. *Its because of the warmth. *My friends SRX is constantly having problems also so he is also trying the boschs. *Good luck. *Ask me anything if you need to.

piranhaZ28: Try Bosch W2CS silver sports gapped at .018, I just finished my third year on same plugs and still no foul outs. I had fouling with NGK at all tempatures and conditions so I called Bombardier race department and they recommended the Bosch and it did the trick. Dino. http://www.snowmobileworld.com/forums/iB_html/non-cgi/emoticons/biggrin.gif

Dino,
Is that a direct replacement for the br9. *Same temp and all?

Thanks Guys.

Dino, I will try that Bosch plug that you mentioned. *That is if I don't dive the sled off of a cliff first *http://www.snowmobileworld.com/forums/iB_html/non-cgi/emoticons/wink.gif

I appreciate the help.

-Josh

Yup bosch plugs are the way to go in this type of conditions.

I still am very pleased with spitfire platinum for what they did with the MXZ 500 but they didnt help with fouling in the warm weather. *Thats because its not really fouling its shorting. *

Its like that bad trick people play on me dont do it because im not sure if its good or bad for the sled but they spayed wd40 on my plugs and they didnt fire until i changed them and put a little gas down the cylinder to wash out the wd40. *

But the bosch plug is doing great so far. *THey are lasting and holding up great. *I think im going to recommend them from now on.

Machzzzz1 what are you talking about??
Mild temp leaves moist air in combustion chamber??
Plug's are shorted not fouled??