dg exhaust, plugs look ok?

[upandgone]

I recently put a dg exhaust on my 89 exciter. Lots of info on this site about putting on an aftermarket exhaust suggested that you needed to rejet your main on the carbs. Well ive only put 15 miles on it since new plugs were put in and the pipe was installed. From what the plugs are sayin according to the chart in the tech section, they are in the good range. Well my concience is getting to me about the rejetting suggestions and that i should have it done, but I would like an opinion of someone who is knowledgable about these engines as to if they look good. This is my first snowmobile and wouldnt like to blow the motor because of my own stubborness and stupidity.

Pic of plugs, one looks a little leaner than the other. Leaner one is darker on one side, almost a black.

 

[98700]

They dont look to bad. I would check piston wash also. Where old plugs used?

 

[upandgone]

those are brand new NGK BR9ES put in day of purchase, only 15 miles on the trip odometer when I pulled them today. (reset it when i loaded it in the truck when i bought it). The old ones were black with ash and gas. Piston wash? Whats the way to check that?

 

[fleet man]

Piston Wash: Look down into the cylinder (best you can) with the piston at BDC and see how much of the top of the piston is cleaned off by the fuel/air mixture. You should be able to see a few spots on the outter edge of the piston where the transfer ports enter the cylinder. Rule of thumb is the clean areas are to be about the size of your pinky fingernail. No smaller though. A "piston wash" search should reveal a ton of info.

Another thing is that the bottom one or two threads are also supposed to be oily and that indicates proper speark pluk heat range. Those plugs don't appear to be all that bad to me.

 

[daman]

Hard to read a new plug,,throw in some old one's....