spit spit

[rooster_20]

I took my 400 out for a ride and I think i flooded it or just straight fouled a plug well i had another one layin around so i poped it in and started it up easy. Here is the problem now its got a spit and sputter when its at idle what is the deal is it just not warm or is my spark plug sucky I took the wire brush on the grinder wheel too it. Any help please?

[F-16Guy]

Too rich. Rejet it using the instructions for the Dyno Jet Stage 1 jetting. I don't know who came up with their jetting charts, but they're way off for the 400ex. For stage 2 you'd need some serious internal engine mods. Install a new plug and rejet to "stage 1" specs.

[rooster_20]

I dont think that is it cause Ive had the stage 2 in for a whole year and dropped down to a 155 main so I think its ok but I will take the spark plug out and check it tomorrow I think I just need a new plug.

[ilpadrino113]

If the plug you had "laying around" wasn't new than ya get a new one. I would never put a plug in my bike i wasn't sure it was rand new, plugs are cheap enough and you only need one of em.

[rooster_20]

Im gonna get one but could it be my fuel mix screw?

[krt400ex]

Originally posted by rooster_20
Im gonna get one but could it be my fuel mix screw?


good guess... ya it is mort likely rich. cuz the same thing happened on the 300(actually i richened it on purpoes and this happened), and i just leaned it out and that fixed it.

[rooster_20]

alright thanks friends
:blah: