What's the deal?

[TimBrp]

Took my 02' xr650r up to Vermont this weekend for some nice riding. First off I have a 172main, 68s pilot, B53 needle in the 3rd clip with HRC tip and all other restrictions removed. We rode at 850feet/ASL too. The bike runs excellent all the time. Well we go out on Saturday morning to get them fired up, took a while, damn cold. Well the bike ran mint for most of the day, then we started on another trail and it was gurgling and sputtering down low but was fine when it hit the main jet. I stopped and the bike would not idle to save it's life. I tried messing with the idle and fuel screw to no avail. What's the deal, it ran fine all day and then just ran like crap. I got it home last night and it did the same thing so I know it's not an elevation change issue. I haven't had time to check yet but I'm guessing dirt in pilot jet, vents tubes blocked, bad gas??? Any help?

[AzMtnThumper]

I've seen a plugged pilot do what you're describing.

[TimBrp]

I'm hoping it's that simple. However, that scares me as to "what else made it through the carb"... ?

[qadsan]

It will likely be dirt or crud in the pilot or float needle seat, etc. I sure wish this bike had a different air box / air filter design.

[TimBrp]

Yah know, I second that. I grease the lip and airbox before I install. It is a wicked poor design on Honda's part. It isn't even convenient, I put one end in and the other comes out. Once you put on the cover you have no idea how it's sitting in there. Now if I find some grease in the carb... ? ... I'm guessing more than likely it's dirt in there or a small partical of these red shop rags I use. Damn things have been fallin apart. I'll repost if I don't get anywhere.. Thanks!

[Old_Man_Time]

I had the same thing happen to me one time. It was after I had installed the S68 pilot. It ran fine and then down low in a ravene it would not idle and started popping and dying like it was lean or flooding. I wasn't sure which was the problem. By the time I got back to camp it had quit acting up. I went home and pulled the carb out. When I checked the pilot I found a string of the glue the factory uses on the rubber bowl gasket wrapped around some of the pilot holes and inside the pilot also. Cleaned it all out and looked for any more strings of sealant, put it back together and have not had the problem since.

Now I run an Edelbrock so don't have to deal with these kinds of problems.

[TimBrp]

I'm getting an edelbrock. Hell this carb stuff sucks. My own fault no doubt. How are the edelbrocks with regards to elevation changes. I mean I was 50 miles short of Canada this weekend and it ran good. I think we went from 800 feet to sea level then up to 3000' and it was fine, until the sputtering. So does the needle need to be constantly changed or the "enrichner screw"??

[Portland_650R]

I've noticed leakage from time to time through the vent tubes, as though my float needle had stuck or something. You DID check to make sure the choke didn't get bumped part way on, yes" ?

[TimBrp]

Yes I checked the choke. Not the issue, however it could do it to..Thanks! I'll get to it tonight or tomorrow and post my findings or my next issue if any. ?

[tirebiter]

If the bike was running ok, and the next minute not, something came loose, your choke stuck, or the pilot's clogged.

The same thing happened to me, said screw this POS, and ordered a Eidelbrock. Before the the Quicksilver showed up on my door I found the prob- crap in the carb( plastic from the tank, someone at honda deemed it wasn't nessessary to put a filter over my petcock], got everything working up to snuff again.

Anyway, still installed the Eidelbrock, back to sorting out a whole new system of carburation. Still at it, time will tell if it's worth the hassle. So far, gas guzzler, with an altitude adjustment prob. I'm sure it'll all work in the end- just gettin tired of the burns on my hands.

Guess what I'm trying to say is find the reason why before you throw money at it.

[qadsan]

How are the edelbrocks with regards to elevation changes.

Mine work great with elevation changes and that's one of the reasons I've bought them for some of our bikes. We sometimes ride at sea level, but mostly at 2,500 to 3,500 feet. We occassionally take a trip to where we ride from 5,000 to 7,000+ ft and I was tired of taking carbs apart on a half dozen bikes and changing out jets because of the kids complaining about performance, etc. I can still tell there's a difference in performance when I change elevations that much, but its not nearly as bad and I can quickly turn the needle adjuster screw on top to enrichen or lean things out by a few clicks if I need to, but I usually just leave it alone. I still really like these carbs and would buy them again, but your current issue should be easily resolved if you don't mind taking the carb apart and cleaning it out.

[TimBrp]

I love to take it apart. Spending time with the pig is great. Something tirebiter said made sense too. I got a new Clarke tank and there was a ton of leftover plastic shavings in the tank from production. However I'm guessing it's dirt in the carb. I'll look into it, I just wanted some opinions. Qadsan, was there an issue before with the Clarke 4.3g tank or edelbrock clearance of the IMS? I forget... ?

[qadsan]

The only issues I'm aware of in regards to fitment with the Edelbrock is when its fitted with a FMF PowerBomb header. The bomb portion of the header contacts the carb, but that was with the older carbs that had the larger machined billet bowls. Edelbrocdk has since switched to a cast bowl that's smaller and it includes a drain screw that the billet bowls did not have. My 'guess' is the newer bowls will clear the bomb portion of the FMF power bomb, but it was more of an asthetic thing than performance because all you had to do with the older billet bowl carbs was can't them to the side a little bit and everything worked fine. One guy I talked to didn't like the looks of his carb canted a slight bit to the side so he indented the powerbomb portion of his FMF header, but that's the only Edelbrock fitment issue I've heard of.

The Edelbrock fits just fine with the Clarke tanks. I had Clarke 4.3's on two XR650R's and on my brother-in-laws XR650R and installed a few carbs for other folks who had Clarkes and there never was a problem. The Clarke tank however has fitment issues with stock California bikes unless you remove the PAIRs smog stuff, but that's just an issue with the California bikes. The older Clarke's fit the California bikes just fine, so something changed along the way.

In summary...No Worries ?

[tirebiter]

"was there an issue before with the Clarke 4.3g tank or edelbrock clearance of the IMS? I forget..."

TimBrp,

I also have a Clarke 4.3, and if you set the carb strait up, it hits the tank a little. Install the Eidelbrock & don't tighten down the intake/exhaust bands till the tank's on. Crank your noggin over, look up under the tank & rotate the carb till it doesn't contact the tank- it's only a couple of degrees. The next time you have to remove the carb, make a note of it's position. Recheck evey time you install the tank.

[XR650R_Bob]

I'm not sure what the settings are on mine because I haven't checked or changed the needle or jets since I bought it last September. I bought it in New Mexico and rode it on back roads at 8600 ft....plus and minus. I live in Dallas, Tx where the elevation is 500 down to 300 ft. I have no problems starting and it runs great. I don't plan to change anything until maybe July. I'm going to be in New Mexico again in May and for 2 weeks in June & July so I don't want to mess it up. I just haven't figured out why it runs so good at these drastically different elevations. ?

[TimBrp]

All set guys. Took the carb off, cleaned up all the jets put her back together and BanG!..she was running first kick. Thanks for the help, it was the pilot that was clogged. Mud, don't ask me "how" it got in there..but it did. Can't wait to ride her now... ?

[tirebiter]

Do you guy's in Mass. mix mud in your gas? If so share your tuning secrets with us west coasties! ?

[SaltyWalrus]

We've had the wettest April in recorded history in Mass. We mix mud in just about everything.

[TimBrp]

Yup, I did about 40 miles on last Saturday in V-mont of waste high mud. Fun as hell. Mud is to us as dust is to you.