I just put a K&N Filter and a E Series White brothers pipe on a 2001 Mojave. I didnt go for the jet kit, but the darn thing hesitates and boggs out a bit. What can I do to fix this?

 

I ran the supertrapp ids2 on my mojave. Try changing the main jet to a 138 or 140 and that should make it smoother.

 

rejet. don't spend a bunch on a jet kit, just go to the dealer and order the next two or three size main jets. I think that would be a 135,138 and 141. Put the 138 in for starters and try it. be sure and adjust the idle speed and mixture. see how it runs and check the plug color after riding awhile. go richer or leaner if needed. Most of the time a 138 works well with a pipe and filter.

You may want to check your plug before you start to make sure it is running lean now.

 

If I were you, I wouldn't rely on plug color. Go up a few sizes on the main jet, until it skips at full throttle, then back down one size at a time, until it stops skipping. That's how I Jetted my bikes, and never had any problems with it being lean. Also, you may have to change the piolt jet, depending if it is too lean or rich. Hope this helps!

 

Are you 100% sure it just started after you made these changes? The reason I ask is my Mojave does this when the valves need adjusted. I have adjusted mine about 4 times in 1-1/2 years and each time they were tight. Have you adjusted yours yet? It actually sounds like it is running rich compared to lean. I know this may sound stupid, but is there a chance you put something in the air intake when you pulled the old filter out to prevent dirt from getting in your carb and forgot about it?

 

Yeah it started fine. What do you mean "something in the air filter"? I did have to cut the support posts that held the factor filter in place, but I of course pulled these out. Do you mean like a cleaner or oil?

I wont say the hesitation is major, but enough to make you wonder what is wrong. It still screams.

 

I just meant that are you 100% sure it started the hesitation and bogging after you put the filter and pipe on and not before. Mine has these same symptoms when the valve clearance gets out of spec. In my case they always have gotten tight. The other thing was I just thought to ask and see if you maybe put a rag or something in behind the filter and then forgot to take it out. You wouldn't have rode very long though and it would have chocked out so never mind that. I didn't cut anything out when I put my K&N in, I just took the white plastic thing out of the air box and put the K&N in.

 

I just hopped back on the Mojave after a few days off. I let it warm up a while and the darn thing still sputters when I gun the gas. As far as the filter, I am certain nothing else is in there but I tried to put the K&N in and it would not go in all the way. Only about .3 CM was sticking out, but I am a bit of a perfectionist. I re-read the install instructions and it mentioned that the posted needed triming to ensure they dont poke holes in the new filter. A bit of info I havent shared, is that the E Series pipe comes with all 10 or 12 exhaust rings installed. I removed about 3 to 4 of the rings per the recommendation of two motorcycle shops. I did purchase the silencer core to quiet it down but I have yet to install it. I know the core will create a bit more back pressure. Do you think that will do the trick? Another note, this quad only has about 6 total hours on it and it ran great till I put the K&N and pipe on.

I really appreciate all the help fellas.

 

Like mojaveaddict and Kawi250 said-you still need to rejet. It's a really easy and cheap fix to your problem. You're letting more air thru your engine, now you need to let more gas in.

 

I agree too that you should go up in jet size. That is the whole purpose of getting the extra air in and out is to add some more gas to it. More air and fuel= more power. It is a cheap way to possably solve your problem. I would also try to find a way to contact white bros or K&N and tell them what mods you have done and describe your problem and see if they have any recomendations.