anyone else have an XL/XR?
#1
anyone else have an XL/XR?
I ride a CBR600F4i in the summer but in the off-season (Nov-March) I am riding my street legal XL250R (1986). It is the RFVC engine with twin carbs and it is a b*tch to adjust properly (running a bit lean at the moment, i think).
Does anyone else have an RFVC honda thumper? Do you know a good forum (like this one) but for my XL? Any experience jetting an RFVC 250?
Thanks
Does anyone else have an RFVC honda thumper? Do you know a good forum (like this one) but for my XL? Any experience jetting an RFVC 250?
Thanks
#2
Yeah My roommate has one, he's got the same problem with his right now actually. Can't help you though, those old XL's are real finicky. You have an F4i? why don't you just ride that? :P
Just playing. found a decent page for you with some things to try. http://www.dansmc.com/carbs.htm the stuff you want in near the bottom.
Just playing. found a decent page for you with some things to try. http://www.dansmc.com/carbs.htm the stuff you want in near the bottom.
Last edited by WildBill; 02-03-2010 at 01:46 AM.
#3
I have a fairly well modified '95 XR600R and I do most of the work on my father's '84 XL600R, so 'm familiar with the RFVC engine in both single and twin carburetor varieties.
The '83-87 twin carb setups only look intimidating; they are actually not that difficult to get sorted out(they are more difficult to wrestle out of the frame, IMO). The primary carb has an idle screw, pilot jet, and main jet, but the secondary(kickstart side) carb only has a main jet. The idle screw obviously adjusts the mixture at idle, the pilot jet is for low/midrange, and the mains cover the upper end of throttle opening.
Where is it running lean? What color is the plug? What makes you think it's lean? If the bike has been sitting or in storage, the first order of business is to pull the carbs and clean the heck out of them.
http://thumpertalk.com/ is a huge site with information on just about everything, including model-specific fora dedicated to XRs like the RFVC 250. I spend a lot of time in the XR600/650 forum.
The '83-87 twin carb setups only look intimidating; they are actually not that difficult to get sorted out(they are more difficult to wrestle out of the frame, IMO). The primary carb has an idle screw, pilot jet, and main jet, but the secondary(kickstart side) carb only has a main jet. The idle screw obviously adjusts the mixture at idle, the pilot jet is for low/midrange, and the mains cover the upper end of throttle opening.
Where is it running lean? What color is the plug? What makes you think it's lean? If the bike has been sitting or in storage, the first order of business is to pull the carbs and clean the heck out of them.
http://thumpertalk.com/ is a huge site with information on just about everything, including model-specific fora dedicated to XRs like the RFVC 250. I spend a lot of time in the XR600/650 forum.
#5
Thanks guys, I have looked at ThumpTalk (annoyingly doesn't have a search), there is lots of good info there.
The bike had to be torn down AGAIN because the damn head bolts stripped the threads out of the cylinder section.... it is in the shop to get a heli-coil now. The carbs have been cleaned (a few times) but now they seem to be working well.
I also got a new head for it recently (as I found it cheap online) and the one in the bike had a messed up valve. The new head is XR though (not xl) and looks to have been planed down. I also got the bigger (xr) intake snorkel thingy with the new head. I don't know what the new head will do to my fueling issues but...
before the above happened it was running rich on idle and lean (i think) on the main jet. I think this is the case because of the following:
- significant popping/backfires when decelerating.
- bike doesn't like having the choke on to start (starts way easiest with no choke even on cold mornings).
- very rich looking piston.
I ride from sea level to 1500ft above (max). I forget what size my jets are... my roommate (who is helping me with this) might remember. is asking what size main jet I should have a stupid question? should I simply get a slightly bigger main? (obviously I can adjust the idle mixture screw).
Thanks for the help!
The bike had to be torn down AGAIN because the damn head bolts stripped the threads out of the cylinder section.... it is in the shop to get a heli-coil now. The carbs have been cleaned (a few times) but now they seem to be working well.
I also got a new head for it recently (as I found it cheap online) and the one in the bike had a messed up valve. The new head is XR though (not xl) and looks to have been planed down. I also got the bigger (xr) intake snorkel thingy with the new head. I don't know what the new head will do to my fueling issues but...
before the above happened it was running rich on idle and lean (i think) on the main jet. I think this is the case because of the following:
- significant popping/backfires when decelerating.
- bike doesn't like having the choke on to start (starts way easiest with no choke even on cold mornings).
- very rich looking piston.
I ride from sea level to 1500ft above (max). I forget what size my jets are... my roommate (who is helping me with this) might remember. is asking what size main jet I should have a stupid question? should I simply get a slightly bigger main? (obviously I can adjust the idle mixture screw).
Thanks for the help!