spark plug question

[Holty]

o.k., i just installed a white bros. pipe(left stock header) K&N filter and outerwear(no airbox lid) and jetted(i had my local shop do the jetting). the bike runs perfectly fine, but is very hard to start in the cold weather. on sunday morning it took me an hour to get it running. I thought I flooded it so i let it sit there and i decided to pull the plug to see what it looked like. It was very black and a tiny bit moist, but not real wet. after i cleaned up the plug a little bit, it fired right up! what does this mean? i don't know how to tell what is wrong with a motor by looking at the plugs. BTW, it is the stock plug. the bike has only like 10 hours on it. also, i don't feel safe running without a airbox lid. will i have to rejet if i put it back on? will it cause harm to the engine if there is not enough airflow(i believe is called running too rich)? thanks

[knighttime]

What jets did the shop replace and what size are they?

[Holty]

good question, but I don't know?

[knighttime]

call and find out

[Holty]

I just talked to my mechanic. He said he followed the stage 2 directions with the Dynojet jet kit. 170 main jet and new needle for under 3,000 feet. does this help?

[kc 300EX]

That sounds a little rich to me, but first thing i would do is buy a few new spark plugs, and some smaller main jets, and do plug checks on every main jet til the plug is brown like it should be

[redrider ex]

yes thats to rich i would drop back down to a 160 to 165.

[01ytrx400ex]

You definitely need to rejet leaner.

[Wheelie]

The 170 is way too rich, try a 155 or 158 main jet.

Why are these dealer putting a 170mj in a piped 400? They should know better. Running without the airbox lid is fine as long as you have an outerwear for your filter. If you decide to put it back on, you will have to step down 2 to 3 sizes on the main jet.

It wouldn't hurt to put a new plug in after you rejet it.:)