[xr650r_sm]

Are cutting holes in the side panel and installing an aftermarket airfilter worth doing on the XR650R? I see some people do it but can you tell a difference in power when doing that? My bike is stock except for being uncorked and having the HRC exhaust tip installed.

Thanks

 

[XR-MANU]

http://www.4strokes.com/tech/honda/airbox/

Jetted right ,you don't lose at the lower revs but gain in mid and top. With a stock motor,don't go to wild .

 

[alexchannell]

http://www.4strokes.com/tech/honda/airbox/

Jetted right ,you don't lose at the lower revs but gain in mid and top. With a stock motor,don't go to wild .

I have yet to hear anyone not loosing low end. I tried and couldn't get the low end as strong either. Some speculation about air velocity too low at lower RPMs...I am not so sure though.

 

[carlsoti]

Maybe one of those "powernow" systems would help the situation.

 

[hondacrf150f1]

I did a venting job and i couldnt get the bike jetted right, the low end suffers a lot....

 

[XR-MANU]

With a stock motor,don't go to wild .

BTW: In '01, I did it on my (then) complete stock motor with stock exhaust (Euro model- no plugs), just a good aftermarket airfilter and a home made BFS + airboxmod (5 holes of 35mm). Ones jetted right,no low end lost ,gains mid to top. :bike:

 

[xr650r_sm]

BTW: In '01, I did it on my (then) complete stock motor with stock exhaust (Euro model- no plugs), just a good aftermarket airfilter and a home made BFS + airboxmod (5 holes of 35mm). Ones jetted right,no low end lost ,gains mid to top. :bike:

Do you remember what jet you started with before the mod and what you ended up with after it?

Thanks for all of the replies.

 

[XR-MANU]

Do you remember what jet you started with before the mod and what you ended up with after it?

It's a long time. :headscrat

I think : 68S, 175 main ,needle 1 clip ritcher,this with all the intake mods.
Sea level , + -15°C.

 

[xr650r_sm]

I added the vented side panel, UNI filter and went from a 172 main to a 178 main, I lost a ton of lowend, it wont wheelie for crap now off the throttle. Could being jetting one jet too rich make it run that much differently? It is so different I am tempted to put the 172 back in and see what happens.

 

[XR-MANU]

What pilot jet do you gave? The OEM 65S ?Go to a 68S with the airbox mod.

 

[TRIGUN]

I believe low end is controlled by the pilot, mid by the needle, and top end by the main jet. I think the pilot needs to be a 68S not just a regular 68. The S makes a difference. Here is a jetting guide to help point you in the right direction for the XR650R.:thumbup: It also explains about why the jet with the S is needed.

http://www.xr650r.us/jetting/

 

[xr650r_sm]

Yeah, I am going back to the 68S. I had that in then went to a 70S with the airbox mod. I went back to a 172 and left the 70S in for a long ride today, it was still really soft on the bottom. I think the 70S is way too fat. Not sure why I got so excited about a 70S!! Thanks for the replies.

 

[XR-MANU]

Try to lean the needle out with the 70S . I found out that it helps to bring the crisp feeling back with a richer pilot.
Try al so to duck tape a portion of the holes in the airbox (making it richer) and look what it brings you. You can put on/off the tape when you go test riding.
It's any easy way to "try and error" :thumbup:

 

[xr650r_sm]

I put the 68s pilot back in and the torque is back. The holes in the side panel dont rob the torque, it was overly rich pilot in my case. It ran weak as hell on the bottom with the 70s in there, it wouldnt wheelie in 2nd gear off the throttle before, now it will throttle wheelie in 3rd better than it did in 2nd before. I didnt know the pilot jet affected it that much. Now the top end feels a little weaker, I will try a 175 in place of the 172 I guess. I need to take a longer ride first though, it should surge at full throttle if the 172 is too small right? Thanks for all of the replies. EDIT: That pig pen jetting page is dead on what I have in there for my conditions(temp and elevation, side panel cut out)