[Dudley1995]

Hey guys I’m new on here ... I have a 2002 Honda 400ex I’m workin on for my buddy... it has k&n air filter and a excellerater exhaust by DG performance... it idled fine but as soon as you got into it it would cut out .. unless you turned the choke bout half on then it would run pretty good .. I need a starting point for the carb .. jet size and needle position?

 

[JohnnySolo]

Welcome to the forums! When was last time this carb was cleaned and had a rebuild kit put into it. Seems like your jets could need replacing.

 

[SlammedRanger]

Full pipe or just a slip-on? Air box lid on or off? And what elevation are you at? Welcome to the forums!

 

[alloutdoors]

I think a good carburetor cleaning is needed and strongly recommend a OEM rebuild kit. I would check the petcock, and all valves within the carburetor, i.e., needle, float, etc.

 

[Ksweenz092]

If anyone could help me I would highly appreciate it. I have a 2000 300ex and having similar issues. Starts right up fine, will idle, but the second I snap the throttle from idle to wot real fast it bogs out at first or will even die if I don't let off wot quickly. Seems like when I'm riding with a load on it, when I take off it's boggish unless I play with the throttle. I cleaned the carb. But noticed it has a 118 main jet. Could having a 118 jet and full fmf megamax exhaust be the culprit? Also has k&n with two 1.5 inch holes in lid.

 

[Ksweenz092]

Also forgot to mention it runs rich. Smokes slightly blueish oily smelling and plug was black crusty and dry. I'm assuming maybe new rings or valve seals? But could this also be an effect of my bike running like I previously explained?

 

[SlammedRanger]

Also forgot to mention it runs rich. Smokes slightly blueish oily smelling and plug was black crusty and dry. I'm assuming maybe new rings or valve seals? But could this also be an effect of my bike running like I previously explained?

Yes if its smoking blue that is oil burning. Does it do it worse when riding and revving it? Or only at start up then go away? If you are burning oil from bad rings you are losing compression. And will never get it to run perfect until its not. Your jetting to me sounds real lean for a full pipe, filter, and holes in airbox. I wanna say 118 is stock or very close to stock. I would be figuring about 4 to 5 steps higher on main jet for your mods. There isnt any chance it has a dyno jet kit right? Because a 118 dj is on a different scale then a oem keihin jet.

 

[Dudley1995]

Yes the quad I’m workin on has a k&n filter on it .. with the air box lid on it .. I live at 640 ft elevation... and the exhaust it has on is a called a xcellerater by dg performance.. not sure if it was jus a slip on.. but I took the carb apart n cleaned it .. seemed like it was pretty clean.. all except the overflow in bowl of the carb was jammed but I got that fixed

 

[Dudley1995]

I have a video of it running .. but I don’t kno how to post it .. also it idles decent wen I flip the choke on a little bit

 

[SlammedRanger]

42 pilot jet. 160-165 main jet. Should make it run alot better. Put the mixture screw at 2 1/4 or 2 1/2. I would also drop needle one clip down from top. My .02

 

[JohnnySolo]

I have a video of it running .. but I don’t kno how to post it .. also it idles decent wen I flip the choke on a little bit

Post it on YouTube then copy and paste it's link here

 

[Dudley1995]

http://www.youtube.com/watch?v=rABO1b6VEZ8



Thers the link of it running ...it jus stutters really bad until I turned the choke on a lil n then it runs decent

 

[Dudley1995]

I’m not sure what kinda jets it’s got in it either cause they don’t say anythin on em

 

[JohnnySolo]

Unless I missed it I don't think you said you bought and used a rebuild kit. Need to get you one and replace the parts. Be sure on idle screw and fuel adjustment screw you count how many turns out you have to do. To do this before taking it out, screw it in and count how many hole turns it is and write it down. When you replace all that, clean everything and spray entire carb out with compressed air. Should be ready after that. Let us know what happens

 

[SlammedRanger]

If the jets dont say anything on the side sometimes the number will be etched into the tip near the nozzle. If there is actually no numbers they are mega genaric jets and god only knows what size they actually are. Get you some oem keihin jets for the carb from jetsRus or somewhere like it and start with my suggested sizes. I would jump to the carb being dirty until you have the right size jets in it. Your discription sounds spot on for lean jetting.

 

[Dudley1995]

Ok thanks guys ... I have a rebuild kit on the way but I cleaned the carb ... and everything looked free n clear .. another thing I noticed on the bike .. when u hit the throttle .. about 1/2 to 3/4 throttle the throttle wants to kinda bounce ...or like vibrate

 

[Ksweenz092]

Yes it gets worse with revving and riding although I haven't had a chance to rude it far enough or long enough to determine whether the smoke goes away or not but I've let it idle till warm and red it and still smokes. Not sure on how to tell if the jets are dyna or oem. Just says 118. I ordered an fmf power up jet kit, will hopefully be here tomorrow. I will switch the jets and reclean and see what happens. Do you think rings should be added to my shopping list as well?

 

[SlammedRanger]

Yes it gets worse with revving and riding although I haven't had a chance to rude it far enough or long enough to determine whether the smoke goes away or not but I've let it idle till warm and red it and still smokes. Not sure on how to tell if the jets are dyna or oem. Just says 118. I ordered an fmf power up jet kit, will hopefully be here tomorrow. I will switch the jets and reclean and see what happens. Do you think rings should be added to my shopping list as well?

Hard to say if its rings or what it is. You will need to do a compression test to confirm it. Do a dry test. Then put some oil in the spark plug hole and do it again. If the number spikes way up you need to pull the topend and see if its in need of a bore. You do this by mic'ing the cylinder. And inspecting for any scratches. You will need a piston and rings in what ever size the cylinder has to be bored and honed to. This is a job for an engine machine shop.

 

[JohnnySolo]

Yes it gets worse with revving and riding although I haven't had a chance to rude it far enough or long enough to determine whether the smoke goes away or not but I've let it idle till warm and red it and still smokes. Not sure on how to tell if the jets are dyna or oem. Just says 118. I ordered an fmf power up jet kit, will hopefully be here tomorrow. I will switch the jets and reclean and see what happens. Do you think rings should be added to my shopping list as well?

Hard to say if its rings or what it is. You will need to do a compression test to confirm it. Do a dry test. Then put some oil in the spark plug hole and do it again. If the number spikes way up you need to pull the topend and see if its in need of a bore. You do this by mic'ing the cylinder. And inspecting for any scratches. You will need a piston and rings in what ever size the cylinder has to be bored and honed to. This is a job for an engine machine shop.

What's the oil for?

 

[SlammedRanger]

It serves as a temporary seal for the rings.