When I start the 400 up it spit sputters and back fires, with a little blackish smock out the pipe. If I take out the air filter you can smell alot of gas on it. Any ideas would be great. Thank !!!

 

for some odd reason (and i have no clue why) but your carb my be running slighlty backwards and putting a gas and oil mixture into you filter and out your exhaust. that may be the black smoke, the gas igniting the oil and the oil is causing the black smoke. A VERRY far fetched geuss but you never know?

 

HOW CLEAN IS YOUR FILTER? THE SPUTTER PROBABLY COULD BE CURED BY UPPING THE PILOT JET 1 SIZE. 400'S ARE JUST COLD BLOODED

 

try something really simple. Change out your spark plug. 400s, for some reason, tend to foul out spark plugs after some time. Check out your filter also. I wouldn't go changing jet sizes right yet. There has got to be a problem somewhere.

 

Sounds like it is running rich. My guess on the filter is that it hasn't been cleaned in awhile. If you live where its cold and make short runs a lot they tend to not burn off the excess as easy. My guess on the oil is that it may be to full or you have blown some seals, which I guess could be the cause of some of the other problems.

I have a question for you... Does it run ok when warm, or does it still smoke? Also is the front part of your pipe really hot or red in color when idling?

 

OK for starters thanks for all the replys. 1)Oil level good.2)I thought of the plug changed it.3) used PJ1 filter cleaner spray and sprayed it with the foam to trap the dirt.
The smoke does seem to clear up after ridng it (if you can keep it from stalling). The pipe does not get red at all. The bike ran awsome when I put it away one day and I went to take it out about 3 days later and it started acting up. So any more help would be great . Thanks again for your help........

 

Well now I am wondering if we have a gas issue, maybe to low of octane or maybe just got a bad batch and it has clogged it up a little.. I would be temped to dump some "boost" into the tank and see if that helps it out. If you are going to try it make sure its the good stuff, not a ton of additives in it. Second thing I would try, pull the carb off and go thru it and just clean stuff up and put her back together..

Good luck and hope that helps you..

 

Ok once again thanks for all the help ! I am going to drop the quad off to Honda and let them take a look at it. When I get it back I will post what was wrong with it, in case someone else runs into this trouble. Thanks again !!