XR650L Exhaust Studs aka "Can'o'worms!

37 replies to this topic
  • August West

Posted December 04, 2007 - 06:10 PM


Thought I'd spruce up my 1993 XR650L by putting an FCR-41 carb and an FMF Powerbomb and Q2 can...Went to work on taking off the stock header and thought I'd soak the rusted nuts and studs with PB and take a few days to slowly work off the nuts and/or the studs.

Well I managed to get one stud to come out with the nut frozen onto it:applause: , one nut off:applause: , and the other two studs snapped off:banghead: :busted: , leaving about 1/2 inch exposed.:lol:

So then I sprayed more PB and put two nuts on the stud that allowed the its nut to come off and tried to back out the stud:busted: ...I snapped that stud too:foul: .

Then I called my local Honda repair guy and he said I should have cut the nuts off with a Dremel, leaving the studs intact:prof: ...brilliant! I somehow had the idea that it would be a good idea to replace the studs, seeing how rusted they were.:thumbsup:

I've since drilled out two of the studs and tried an EZ-out, which snapped inside one of the studs:censored: ... none of my drill bits would even scratch the shorn-off EZ-out. Luckily, I could Dremel-cut the stud back to the cylinder housing at which time the EZ-out fell out:applause: ...none of the studs would respond to the EZ-out:mad: .

This still leaves the one stud which I can't get to because it's too close to the centerline of the bike and the frame downtube is in the way of my drill:crazy: .

Okay, the long and short of this meanderance is that I will probably have to take the motor out of the frame:cry: and take it up to Eureka to have some engineering outfit laser the studs out.

What was supposed to be a fun-filled Saturday fitting my new FMF powerbomb and Q2 and Keihin FCR-41 has quickly turned into a week of frustration and who knows what the laser guys are going to charge me for cleaning out the stud holes.:ride:

I'm not the type that gets silly frustrated...I consider all the above as lessons learned.

Can't wait to get it all running again so I can go riding!:busted:

  • frankiewhipit

Posted December 04, 2007 - 07:04 PM


Having turned wrenches for 26 of my 41 years on earth, I have learned to always use the torch on any exhaust hardware. At least you can ride it when it's back together, it's 24 degrees here in NY.

  • August West

Posted December 04, 2007 - 09:02 PM


Oh,yeah, I forgot to mention that I used a torch throughout my whole ordeal mentioned above. Torched the aluminum only, torched the stud only, torched everything at once!

  • Maroast

Posted December 04, 2007 - 09:12 PM


Yikes!!! Sorry that I have nothing to contribute but my deepest condolences....

Its a total killer when you take on an "easy" project that will take 4hrs at the most....then it spirals down into a despair filled sh*t-fest.... good luck...and the next time you jump on your bike and crack that throttle (which will now be linked-up to a pumper :thumbsup: ) you will have forgotten all of this mess!! :busted:

  • XRsteve

Posted December 04, 2007 - 09:25 PM


Wow, I hope I never need to take mine out. I did on my XR400, and used a little anti-seize when it went back together.

  • XR650L_Dave

Posted December 05, 2007 - 08:39 AM


Yer supposed to use the blue-wrench on the nuts- tough with the engine in place, but they come right off that way if you get 'em red.


  • Kawabuggy

Posted December 05, 2007 - 09:19 AM


You DON'T have to pull your engine out of the frame to remove the head.

Take the head off and take it to any local, competent, motorcycle repair shop or machinist, and they can fix it fairly easily.

When you get it back, be sure to use anti-seize on the nuts when you put them on. After you get them tightened properly, clean the extra anti-seize off the threads of the stud with carb cleaner. Clean them really well. Once they are clean and dry, either spray paint them with high temperature paint, or brush on some high temp. ceramic paint to the exposed threads. If you can keep the threads from rusting, you can stop this problem in the future. As part of my regular maintenance, I always check/clean/lube any exposed bolt threads to avoid these types of hassles in the future. If I am in a hurry, I will simply smear axle grease on them until I have time to do it properly. After a ride, the dirt and grease wash right off.

Good luck with your project. I hope you are able to ride again soon with the upgrades in place.

  • martinfan30

Posted December 06, 2007 - 01:55 PM


kawabuggy has some good advise...

follow that and you'll be good!

what fcr you have? if you need any jetting help, let me know. i have the fcr from sudco, slant, no choke. 158/52, emr needle middle clip, 2 turns out on an extended fuel screw(a must!!!).

  • cleonard

Posted December 06, 2007 - 02:58 PM


+1 on what Kawabuggy said. When you have the engine apart check everything that you can. Get the valves looked at and do your best to see how the piston and bore are. If it needs fixing now would be a good time.

  • August West

Posted December 06, 2007 - 07:11 PM


Okay, a progress report...

I spent three hours carefully dissassembling my bike and removed the engine:applause: ...the engine was lighter than I thought it would be and was easily hefted into the back of my truck. The whole process was really rewarding as I've never done anything as intensive as this project on my bike.

I then drove it up to Eureka to a fellow named Andy Gordon, who's got what seems like a top notched machine shop in the garage of his house and showed me this gadget that he'll mount on the one free stud hole that I'd managed to get loose. $50 per hole...so 3 stud holes and another hole where the block-off plate goes...somehow that one had got sheared as well...I'lll consider it $200 well spent as the guy's a class act, a Vietnam vet who'd done his tour on an aircraft carrier, which he said they've since sunken off the Florida coast for reef-building.

Of special interest regarding the stud bolt holes...they exit to outside airspace! I was so worried about drilling through my bolts and into the cylinder walls. Once I had the engine up and on a table, it was easy to see how the stud bolt holes were designed...hats off to Honda:worthy: !

I've ordered new stud bolts, nuts, and new exhaust pipe gaskets which I won't get til next week.

I've thought about if I should get into the engine or not and with the advice of my local Honda repair guy, I'm leaning towards leaving it alone as the engine runs great as it stands right now...anyone care to persuade me to put a cam in? I don't think I want to deal with the heat issues with higher compression pistons. I think I'll be pleased enough with the FCR-41 and the FMF Powerbomb and Q2 upgrade, 14 years into the life of my bike!

By the way Martinfan30, I'd ordered the XR650L kit from Sudco for $516, which is the carb, two push-pull throttle cables, and some other pieces. I'm under the impression that it is the slant body FCR-41, as opposed to the FCR-41MX. I'd been reading your posts and others on this subject and then called Sudco. They hooked me up with the kit plus a 45 pilot jet as I'd followed Burned's posts and saw what he suggested (170 main emr needle 3 clip 45 pilot 100 pilot air 2 turns fuel screw)... thanks for your offer of jetting help!

I'd also ordered a flexible screw from XRonlys...anybody know if that's the one?

I will do what Kawabuggy says...anti-seize the stud bolts and nuts, clean-up the excess anti-seize, and then paint to slow down rust process. Great advice:prof: !

So far I've been enjoying this whole process bonding with my machine. Thank you all for the help!:thumbsup:

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  • martinfan30

Posted December 06, 2007 - 11:17 PM


same carb kit as i got to. my longer fuel screw is from research and developement(R&D). same cables too.

not to second guess eddie, but i tried the 45 pilot also.... no good for cold start. had a very hard time getting it going in the morn(with no choke on it).

go with the 52 pilot. you may even end up with the 55(im at 4300 ft). you'll see what i mean! one good pump at 32 deg. f, and it starts and idles perfectly. with the 45.....:thumbsup:

also the 170 main, thats a joke on the 650L. it will barely run. did that too!

i finally settled on the 158 main. 160 might be best at sea level.

2 turns out. good luck and let us know how it goes!

  • August West

Posted December 07, 2007 - 10:23 AM


I checked my FCR-41 last night to see what jets Sudco set it up with (I told them I live in Northern California, they didn't seem to care what elevation I was at:confused: :

Main jet 170
Main air 200
Slow jet 50
SAS was 10/12ths out
EMR needle middle clip

I live at 310 feet but ride mostly from 500 feet up to 3000 feet in the passes around here. I'm thinking to order up some different jets. If Martinfan30 is using a 158 for the main at 4300 feet, it would seem that I'd be better off somewhere between 158 and 170, huh?

The XRonly FCR fuel screw fits the pilot screw but I needed to pull the handle off so I could fit it through the float bowl access hole. Seems like the flexible fuel screw is too easy to turn, possibly moving while riding...anybody experience this? Seems like there should be more resistance...

Supposed to be sunny this weekend...guess I'm going to have to ride my 1200GS while the 650L's all laid up:ride: !
Y'all have a great weekend!

  • martinfan30

Posted December 07, 2007 - 10:53 AM


if you think about it, most guys at or near sea level with daves mods run 158/55. i ran the same jetting on my cv carb(djet kit) as i do with my fcr.

you may try160/55 as a good starting point also.

  • Motosprtman

Posted December 07, 2007 - 11:17 AM


Man I feel for you, that is one nasty time with some more than stubborn studs. Although I am coming into this thread late - I just wanted ot add some information that has worked well for me in the past on stuck stuff, Try using Kroil - really seeps in and although not a sure thing is the best solvent / break free / pentrating liquid I have found.

  • exaresix

Posted December 07, 2007 - 04:33 PM


Do not open the carb when you get it from Sudco! Send it back and tell them you want the same carb WITH A CHOKE. You can also buy the front and rear bells separately for the carb that has a choke. The kit you bought does not have a choke on the carb, and with a 45 pilot jet (a good size) you will be miserable trying to get it started. You should also buy from sudco the idle adjuster cable that bolts to the carb body. The wiggly pig tail knob that comes with the carb is always flopping around in the wrong place and will eventually touch something hot and get melted. Yes, I know some people zip-tie it in place, but that is a real cheesy solution.

  • martinfan30

Posted December 08, 2007 - 11:46 AM


I know we have gone over this before, but i dont have ANY starting issues by using a 52 pilot and no choke. its 25 deg. outside right now and the pig hasnt been started in a week.

after a few squirts and 3 hits on the starter she runs and idles.

  • August West

Posted December 10, 2007 - 09:21 AM


Okay, so I've ordered some jets from Carb Parts Warehouse...

Main Jets: 158, 160, 165
Slow Jets: 52, 55

$9 plus $9 2nd Day Air equals $18.

I got the 165 to bridge the gap between what Sudco recommends and what martinfan30 recommends.

I get the engine back Wednesday, install Thursday, ride Friday???:banghead:

  • martinfan30

Posted December 10, 2007 - 09:55 AM


let us know what u settle on.

  • Brtp4

Posted December 10, 2007 - 11:31 AM


August, jetting is a process of trial and error, then verification. Often the advice I have gotten in the past has sent me in the wrong direction, so please be careful.

First of all, jet sizes on a different carb, such as the CV, have absolutely no relevance to the FCR. None. Zero. So forget jet sizes that have anything to do with the stock CV.

Second, the best way to do jetting for a novice - which is 98% of the riders out there - is to start with a baseline and then make changes in single increments. Jumping up or down more than 1 or 2 sizes is analagous to skipping the trial and error process, which means it is a guess.

Third, the pilot air jet has a direct relationship on the pilot circuit, and thus the pilot jet you will need.

Here is a quote from Burned:

One last Q: Seems several XRLs are at 50 or 52 pilot, I am at 45. Should I try the 48?[/I]

you see the bigger pilto jets on the other bikes because they run the pilot air jet bigger/farther out.the pilot jet and pilot air jet are a direct realtionship.

neither.there is no difference between a 45/100 combo vs a 52/125.its the same ratio of fuel to air.

It is common to treat the jetting process like choosing tire sizes, where size jumps have small consequences.

Even when you find a setup that seems to work well, old-school thought is to go up/down one additional time just to see if it works better. Nowadays though, four strokes are easier to jet plus dynos and air/fuel testers are common.

I agree with Martinfan 30 on the main. I have a 160 and it seems a little rich. Seemed OK at first but over time I think it is too big, especially because a lot of my riding goes up from my base alt (3400'). My GUESS is to start at a 160 or 162 max.

Regarding the choke, having it would not hurt but I can tell you that my bike starts as good as any motorcycle I have ever owned with a choke, because of the pump. It might be better to have one, but for me it has not been a problem. Exarsix is dead-on though about the idle adjustment setup being lame, and I am gonna call Sudco to order the system he describes.

Finally, regarding the motor....I don't want to contest what anyone else likes for their setup, but please consider your riding to make this choice. If you are riding at least 50% off road I think the XRL has other deficiencies more serious than the motor. In fact, once you improve the throttle response the power delivery of the bike is one of its best attributes, the rotating mass is super heavy, ignition advance is tame, mild cam, so the bike puts out power at a very, very low RPM, and rarely stalls. Perfect for a tall, heavy bike, with really wide gear ratios, and cheap suspension, on snotty terrain.

If you ride a lot of street or fireroads, it is a completely different story, more power would make the bike a lot more fun.


  • martinfan30

Posted December 10, 2007 - 11:43 AM


thats great advise on jetting. he is setting up an fcr. it also is kinda funny how my old cv carb used the same jet numbers as i do now on my fcr. the reason (as you may know) i recomend the 52 pilot like on mine is because of the non choke model i have. a 45 was very hard starting, 50 better but still cranked a while before starting. 52-perfect starting, not to rich down low either.

you are also right concerning other shortcomings other than the engine. the suspension can benefit greatly from some work, and the stock tires are terrible.

but if you are a HP whore such as myself, the engine comes first!Lol:thumbsup:

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