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Is it Possible to Break an XR?

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I think I've done the impossible - break an XR. I was running the Ironman last weekend and doing okay, but on the second lap I hit the big hillclimb and halfway up, the gearbox started banging loudly like it was hung between gears (I was in second at the base of the hill). I made it to the top and stopped to check it out and the only gears I could get the bike to go into were neutral and fourth. I limped across a corn field to the truck in fourth. I got it home and cleaned it real good (lots of mud from the race) and now it will only go into neutral and first - nothing else. Theres no shift lever to case interference and the oil is clean and at the right level. Thel clutch plates, springs, and cable have about 12 races on them and don't appear to be the problem. I'm going to do some exploratory surgery, but thought I would check here to see if anyone has any ideas of what I should look for. There are no abnormal sounds coming from the gearbox or anything, it just won't go into all of the gears. Any help would be appreciated. Thanks in advance.

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My XR400 had a cracked head. The dealer told me "the cracked head was most likely a manufacturing defect because normally XR's don't break down." But "normally" isn't 100% reliability so yes, I suppose XR's can break. But one things for sure and that's the fact that your XR didn't leave you stranded. That's what I like about my XR. It can limp itself back to civilization.

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So the engine still seems to run ok, just won't shift and initially made alot of noise in the lower end.

I guess the first things I would look at would be the shift forks, shift plate and shift drum.

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That's what I like about my XR. It can limp itself back to civilization.

Last year my bike had a malfunction 20 miles from the truck. I was able to ride back to the truck, and when I got home and tore it apart there was a 1" x 1 1/2" piece missing from the piston skirt. That's what I call piece of mind.

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I have just pulled the head off my recently purchased 86 XR250R and can see 2 small cracks from the spark plug to the valve seats. I have been looking around for a replacement head but no success so far. This is the single carb RFVC model which I was told wasn't usually a problem with that year. Anyone have any knowledge with this? Can the head be repaired successfully? What is the material composition of these heads for welding purposes?

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To the OP; I think you blew the gear box. I've had this failure and the next step is to pull the right hand side case and start looking for broken shifting parts and/or debris, also check the oil filter. Most likely is a problem with the shifting mechanism but broken gears can happen. If you find debris you will need to split the cases to clean things up and inspect all of the gears and shifting parts for damage. Get a Honda shop manual.

I think the combustion chamber and valve seats are iron; the aluminum is cast around the combustion chamber piece. A TIG welder might be able to patch it but I doubt the fix will last. Cracks in the blocks and heads of heavy duty engines are often repaired with dowel pins; I've done this on diesel engines with good success. If the crack goes into the valve seat you will need a new valve seat. Any head rebuild shop can install a new valve seat but the crack repair is more difficult. Suggest you shop around a few head rebuild shops.

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I think I've done the impossible - break an XR. I was running the Ironman last weekend and doing okay, but on the second lap I hit the big hillclimb and halfway up, the gearbox started banging loudly like it was hung between gears (I was in second at the base of the hill). I made it to the top and stopped to check it out and the only gears I could get the bike to go into were neutral and fourth. I limped across a corn field to the truck in fourth. I got it home and cleaned it real good (lots of mud from the race) and now it will only go into neutral and first - nothing else. Theres no shift lever to case interference and the oil is clean and at the right level. Thel clutch plates, springs, and cable have about 12 races on them and don't appear to be the problem. I'm going to do some exploratory surgery, but thought I would check here to see if anyone has any ideas of what I should look for. There are no abnormal sounds coming from the gearbox or anything, it just won't go into all of the gears. Any help would be appreciated. Thanks in advance.

What year XR? I seem to remember there being a problem with second gear on the pre-'98 XR4s. Also, do you use your clutch to shift, or just stomp it into gear? If the latter, then that may help explain such a freakish occurance.

JayC

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Chuck- I think you're right. I removed the right side cover and I'm finding many parts of what I think used to be 2nd gear. Time to split the cases I guess.

Jay- I always use the clutch, but I'm wondering if I might have accidentally hit the shift lever midway up the hill. I wear a size 13 boot and it's happened before. I guess I need to adjust the lever differently, I dunno. So should I order a 98 or newer 2nd gear or is it not a direct replacement?

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Man,

You're just the guy I want to talk to! My cousin placed 5th in the Senior B Class the same day. I haven't raced GNCC's for 12 years (on a CR250) and was thinking about doing a couple next year just for the heck of it. I have owned every XR...250, 280, 400 and 650R (present). Of all of them, I really feel I'm the fastest on the 250's...unless things really open up. YOU know how the GNCC's are though. LOTS of really snotty stuff. Heck, even Powerline Park had some tough spots...and it was a dry day!

Right now, I have a 2003 CRF450R and a 2007 XR650R. I was thinking about selling one of them to get a 250 again, but I wonder if they give up too much power to the other bikes. Obviously, I'm not expecting a podium finish. The 650 is quite a bit to handle in sloppy tight stuff and the CRF seems to run the best when it's on a motocross track. It doesn't seem to like the technical stuff. I'm sure that the right rider could make either of them work. I can't help but wonder how the XR250 would do. Oh, I would be in the Super Senior C class and I weigh about 165.

Thanks

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broke an XR ? That is like all the other things you read on the internet. I will not believe it until I see it with my very own eyes.

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Yes, Run the wrong oil and get the engine hot and the head , cam and followers will go south in a hurry.

Dwight

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Man,

You're just the guy I want to talk to! My cousin placed 5th in the Senior B Class the same day. I haven't raced GNCC's for 12 years (on a CR250) and was thinking about doing a couple next year just for the heck of it. I have owned every XR...250, 280, 400 and 650R (present). Of all of them, I really feel I'm the fastest on the 250's...unless things really open up. YOU know how the GNCC's are though. LOTS of really snotty stuff. Heck, even Powerline Park had some tough spots...and it was a dry day!

Right now, I have a 2003 CRF450R and a 2007 XR650R. I was thinking about selling one of them to get a 250 again, but I wonder if they give up too much power to the other bikes. Obviously, I'm not expecting a podium finish. The 650 is quite a bit to handle in sloppy tight stuff and the CRF seems to run the best when it's on a motocross track. It doesn't seem to like the technical stuff. I'm sure that the right rider could make either of them work. I can't help but wonder how the XR250 would do. Oh, I would be in the Super Senior C class and I weigh about 165.

Thanks

I'm not exactly the voice of experience, as the Ironman was the first GNCC I've ever tried. I've done some local HS, but that was a whole difference game. I was holding my own (in 1st year racer class) and until it broke, the bike was definitely not the limiting factor in the equation. I'm a big boy - I've got about 100 lbs on you so the 400 and I get along ok. It has the grunt to haul my big butt around and I have the strength to muscle it around in the tight stuff. The Ironman had a field section that was nearly a mile of zigzags through a corn field and I passed as many people there as I did in the woods. That is with the exception of the 20 guys I passed at the foot of the pro hill climb - they were just sitting there in awe at the size of the hill and me and the bix XR went around them and right up the first lap. It's my opinion that in any class lower than the A class, it's mostly about the rider and has little to do with the bike. I doubt that I would be appreciably faster on the hottest new bike.

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Just an update to the original post:

It was indeed a busted 2nd gear that ended my day. I've got the cases split and the damage assessed and parts are on the way. The job has gone pretty smoothly so far, so we'll see how it all goes back together when the parts get here. The shop manual has been invaluable. I can't imagine doing something like splitting the cases without having it. :worthy:

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A couple of weeks later and a couple hundred bucks later and the old XR is alive again. Finished it up last night and took an easy 4-5 mile ride and everything seems good. :thumbsup: I was amazed at the overall excellent condition of the internals of this 12 year old bike. Everything I checked was within spec limits listed in the manual and I don't think the engine had ever been opened up before. I'm racing it this Sunday, so that will be the real test. If you ever find yourself needing to split the cases, don't sweat it. It's really not that big of a deal if you have a clean work area and you label everything.

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You can break an XR by rolling it off a 600-foot cliff or by accidentally parking it in a car compactor. Otherwise you are out of luck. :^)

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