[REVNECK]

I know this sounds pretty dumb....can plugs with lots of miles on them loose performance?? 3900 miles on them to be exact...

2005 600 HO
Cudney Kit
Reduced Gear
96 Studs

 

[06MXZXRenegade800]

If their misfiring yes, other than that the loss would be unnoticable.

Spark plugs are something you should change every once in a while bud, its called maintenance

 

[REVNECK]

Thanks,
no mis-firing, just a ton of miles. I suppose I will change them for the heck of it...

 

[UP Renegade]

When you change them, compare them to the new plugs. You will probably see that some of the surfaces have become slightly rounded.

3900 miles that is great. I can remember when I couldn't get 39 miles.

 

[Saguenay Bill1]

I just changed mine, only got 13,500 miles out of them. Never had a starting problem, getting 15 to 18 MPG. Oil is at 45:1 ratio.