PDA

View Full Version : What does a plug like this tell you?


BrianWrightR6
10-20-2002, 10:28 PM
I took my plug out today after I had my carb off for the choke removal and it looked a little black, what does this tell you carb gurus and what should I do to resolve it. I have a full E-series with a K&N filter (but nothing done to the air box) and nothing done to the carb, I do have a jet kit on the way (K&N Stage 1). Should this clear the back firing and this up?
beerock
10-20-2002, 10:30 PM
its rich...... try taking the airbox lid off.......
what about the k&n filter?

whens the last time you cleaned it?

it should be pinkish/purple lookin. if it isnt its dirty...... clean it!!!
BrianWrightR6
10-20-2002, 10:56 PM
The filter is still pink and was cleaned not long ago. I was thinking something maybe like this would help. Just what is the material that was used here and what type of metal is that around it that you can cut to hold the filter?

http://home.elp.rr.com/hipo/atv/images/1_filter.jpg
YZROOSTINYA
10-21-2002, 04:30 AM
its aluminum, and its just a peice of cut filter. probally a uni pre filter cause the holes are so large
bmf400ex
10-21-2002, 08:04 AM
that plug looks carbon fouled, not oil fouled, can u still take a picture from the plug standing up instead of laying down?
NTPRacing#19
10-21-2002, 08:08 AM
yup sounds like its a little rich, lean it out and replace the plug and run i for a while and see what you get later
BrianWrightR6
10-21-2002, 11:53 AM
By leaning it out should I modify the airbox lid? What about going up to a 155 main? Will this help?
knighttime
10-21-2002, 12:19 PM
Originally posted by BrianWrightR6
I took my plug out today after I had my carb off for the choke removal and it looked a little black, what does this tell you carb gurus and what should I do to resolve it. I have a full E-series with a K&N filter (but nothing done to the air box) and nothing done to the carb, I do have a jet kit on the way (K&N Stage 1). Should this clear the back firing and this up?

Sounds and looks to me like u r runnin LEAN. All 400's come lean per the official service manual. Since u added the full e-series and k&n, u have increased the airflow through the engine but have done nothing to incease the gas intake, THEREFORE u r runnin the mofo really lean which is causin the backfirin. Up your pilot jet to a 42 and make sure u increase your main jet as well.

good luck
Sparks425Ex
10-21-2002, 01:45 PM
Originally posted by knighttime


Sounds and looks to me like u r runnin LEAN. All 400's come lean per the official service manual. Since u added the full e-series and k&n, u have increased the airflow through the engine but have done nothing to incease the gas intake, THEREFORE u r runnin the mofo really lean which is causin the backfirin. Up your pilot jet to a 42 and make sure u increase your main jet as well.

good luck


I agree 100%. Well said KnightTime
phatswinn
10-21-2002, 03:49 PM
it tells me its too long for the motor... unless 400s are different, the only thing that should hav black is the inside with the ceramic
josh
10-21-2002, 05:26 PM
um, put a new plug in there and run the k&n jet setup and ride the bike for about 1/2 hour, while riding find a straight away, put it in 5th gear and run it at wot for a min or so, after that pull the plug, take a pic and post it and someone should be able to help a little
BrianWrightR6
10-21-2002, 05:35 PM
Thanks I will do that. I should have the kit by Wednesday or Thursday.
Steven
10-21-2002, 05:39 PM
Josh is right on, get a new plug and run that baby WOT for a good reading. Kill the engine, and pull the plug for an accurate WOT reading.

Steve
BrianWrightR6
10-21-2002, 06:08 PM
Hey steven where did you get your Stage II K&N kit?
10-21-2002, 06:14 PM
hay man i was just looken at my plug today it was blacker than that but thats k i called my shop and they sai if it is runnen well but the plug is black u are ok but when u start to have problems with starting and backfireing than that isbad. so if it runs well keeep it in. but my problem is way worse. my plug doesnt stay in tight it alwase vibrates out can sombody please help me i dont know what to do . also i dont have the change rench for the plug and that is the only thing tht will fin in the head what should i do?
R-Crazy
10-21-2002, 06:22 PM
well, the instruction manuel says to put the plug in finger tight, then take your wrench and turn it 1/4 to 1/8 of a turn to snug it up. That is what i did and it if fine.

dave
10-21-2002, 06:26 PM
that is what it is now just FINGER tight but the size that fots my plug the best is a 18mm and the 18mm wont fit in the cilinder but the 17mm will and i dont have my took kit. so what should i do????
BrianWrightR6
10-21-2002, 06:36 PM
I have seen 2 other 400's blow the plugs right out of the top and ruin the thread, I would put them in a little more that hand tight at least snug it to where it is pretty tight. If your plug is vibrating out then it may to be late, you may have to look into heli-coiling it.
10-21-2002, 06:41 PM
hahah hi am deff not running it finger tight that is just dumb but untill i can tighten it i cant go out. but last year i was riding it and i reard a big poof and my plug blew out of the cylinder but all the threds are intact i checked they are all fine i think i just didnt tighten it enough