Have you looked at the air intake on these bikes?? I'm talking about the top end of the snorkle (below the left rear side of the gas tank). THE INTAKE IS MAYBE THE SIZE OF A QUARTER!! What's the deal here? Is Honda trying to detune the bikes by restricting air flow??

What made me look into this is I put an FMF MegaMax II pipe on the Recon and noticed a big improvement in performance (of course I did a rejet). Then I added a K&N filter figuring I would get another boost in performance-WELL NOTHING CHANGED AT ALL! (I didn't drill the airbox lid, because I want to keep the box watertight on this bike.) Besides turning the mixture screw out a little, no jetting changes were needed. SOMETHING WASN'T RIGHT!! Obviously the K&N was capable of much higher flow rates, but was being restricted somewhere else in the intake system. So I looked at the snorkle. The pipe is quite large and looks like it would flow fine. But the intake at top is about the size of a quarter. I cut the end of the intake off to open it up, and sure enough the bike is so lean it hardly runs. I have to do a big time rejet now!! What's going on here?? Anybody know??

 

Hey man good point. I did the exact same thing , you know put the FMF on plus a rejet. Then I also added the K & N and I heard so much about them and how much power they give to your bike. But when I put mine on I was not impressed at all. I never knew the air intake was that small. I kept my lid on to keep the bike water tight and figured it couldn't be the intake so I just shrugged it off and thought it was poor K & N quality. Thanks to your post I took out the intake and cut out the head. I just got back in from riding and I must say I am VERY SORRY for ever having those bad thoughts about K & N. Now I know the shame is Honda.

RRR

 

I looked my 400EX air intake, and it was the same way! It was bigger than a quarter, but it was not as big as it could have been. The snorkel also went further into the air box than it had to and had an indent for the air filter. I looked at it and I thought it was to try to deflect dirt, dust, and mud away from the filter, but it stopped short of the filter end. I had problems with water getting into the air box in high speed water crossings. I decided the best way to fix this was a few carefully placed drain holes. There are low spots in the intake tube but no hole, I know of a lot of other machines that have a way for the water to get out if it finds its way into the air intake, why not mine? I agree, shame on Honda, how am I supposed to hang with a Raptor like this! Honda must have decided to let the owners finish the work on the intake tubes. I know I did a little work on mine.

 

so will I need to rejet my recon after I do the work on this air intake?

 

Pyro,

You probably won't have to. When My Recon was stock I rode with the airbox lid off and I had no need to rejet. So working on the intake won't give you as much airflow as taking the lid off. But if you have a K & N Filter than you will probably have to do a rejet.

 

I noticed that too when I was putting the Supertrapp & Uni on my Recon nearly two years ago. I had to go to a 110 main after I cut the end off the tube but now it runs great! When my Son is ready for a little more power from his 250EX I'll do the same to it too.

 

CAUTION-See my newer post "Second Thoughts on...". This mod may be to much if you have a pipe and a K&N both!!!