Woohoo. New guy with carb questions

[bike: 2001 XR650L; location: Dallas, TX;  elevation: 558 feet]


what's up guys, 


I'm a former (fuel injected) Ducati owner  and recently wanted to get back into motorcycling after a short break (a child, a move, etc. etc.)


I just acquired a 2001 XR650L last week and I'm having a little trouble with it.  The previous owner delivered it to my house, he rode it, I rode it, it ran ok but was "popping" a little when off the throttle.   PO explained, "it does that until it warms up, no worries. that's how the carbed Hondas run."  I've never owned a carbed motorcycle. 


I'm dumb. I said, "oh, okay..."   I decided to do some basic service, since half the fine service records that were provided don't go with this bike - and a receipt for a rebuild the PO told me about (new crank shaft and 10.5:1 Wiseco piston).


The bike had an oiled foam filter in the stock airbox, de-snorkeled, and the foam was coming apart.  I replaced the foam filter with a stock, new, Honda paper filter. 


I decided to check the valves, too.  Three of them were tight - like maybe not closing all the way, that tight. Everything is back in spec now. 


I replaced the spark plug with the standard one (the "8" one) called out in the owner's manual. 


I took the supertrapp off and put the stock muffler back on - much quieter, didn't change the popping.


I drained a little fuel out of the carb and it was pinkish orange and smelled not like anything I am familiar with (I know gasoline, avgas, diesel, Jet-a) so I drained it out.  I refilled the tank with fresh 93 octane. PO later told me it was "race gas, the good stuff".


Now, the bike starts great - but only if on FULL choke. It pops a bit at idle, but doesn't seem to pop while on the throttle. I rode it down the street a bit.  I can't seem to take the choke off without it dying. 


It all points, to me, to a carb issue.  I spoke to the PO and he said it has the "hondaline power up kit in it".  


So, do any of you have a link to a "baseline" setting for this carb?  I'd love to pull it apart, rebuild it with some combo of known good jets, etc, and see if I can get it to Idle.  


Thanks in advance for helping a new guy who should have known better...  damn, I should have known better. 


honda doesn`t make a "power up kit" for these bikes :lol:


pull the carb,,hopefully he never screwed with it...if the main is a 150 and puikot a 50 then its stock..some bikes had a little larger main and pilot...


a 52 pilot or 55 and a 155 main burn the best,,anything bigger usually just carbons vthe engine up,,2 1/4  to 2  1/2 turns on the fuel screw is usually good too..



Check out "daves mods" in the faq section at the top of the forum. It is the stendard formula to wake up a stock xrl carb. As for your specific issue, it sounds like a partially blocked pilot jet. Most of those fancy "race fuels" have ethanol or methanol in them both of which can cause all sorts of problems if left to sit for any significant amount of time. If i were a betting man, i would wager that you will find a mess of nasty ethanol junk in the carb bowl.

My advice is to pull the carb bowl off for a good cleaning, pull the jets and emulsion tube, clean them thoroughly with carb cleaner, compressed air and a torch tip cleaner and record the jet sizes. Then put it back together and see how it runs. If you are happy, all is good. If not, procede with pulling the carb and performing daves mods.

Thank you both for the replies.  I'll pull the carb out and clean it up. 


How interesting to hear that there is no "Power up kit..."   jeez.


SO my plan, based on the feedback above, is to clean the carb and replace the gaskets. While I'm in there I'll check out the jets and see what I have and go from there. 

I rebuilt the carb tonight.  


The "needle jet holder" was caked full of grime and green gas sludge, none of the holes were clear, none.  It had a 150 main and "50S" pilot jet in it - they had been removed several times as they were boogered up a bit at the screwdriver slot. 


The Moose rebuild kit included a "152" main and "50" (no "s") pilot jet.  It also included a new needle and needle jet, I assume these are matched to each other as the profile of the new needle was much different than the old).  I cleaned all of the old parts that I did not have replacements for and installed the new parts that I did have. 


The carb looks AMAZING.  Now, I'll install it and see if it runs any better. 

Hey, also:  I was missing the "jet baffle", #14 in the service manual drawing on page 5-6.  Do I need this? 

The jet baffle (slosh baffle) doesn't seem to be critical.


If it bucks or hesitates over rough terrain that might be caused by it missing, but more than a few folks have reportedly had theirs go missing without ill effects.

Imperialists, I did it. (My phone auto corrects thumpertalkers to imperialists. I feel like it is a unique greeting and I like it). I rebuilt the carb last night and set it on the counter. Sometime during the night. Scrounged up a 5/32 drill bit, took the carb back apart, and did the Dave's mods.

This evening I reinstalled the carb, and tank, etc. I flipped the fuel valve on and let it percolate for a moment to refill the various cavities and passageways.

It started up great with full choke. I was able to move it to half choke almost immediately, and after a minute or two the choke came off.

I set the pilot screw and idle speed per the manual. It runs great.

I'm pretty excited to get an inspection And get out there and ride!


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