XR500 Slipping in first

[Worzel]

Yesterday I took my XR500 out for a ride after putting it back together. I got the bike as a box of bits, but the motor was complete so I did not muck around with it, other than new oil, plug etc.

At first it seemed to go fine no slipping, but as time progressed it seemed to slip under load in first. It does not feel like the clutch as the bike does not rev with no movement, it seems more like a miss or something jumping a cog, but it has a new chain and the front and rear cogs seem to be ok. All other gears seem to be fine and it will lift the front in second.

I stopped riding and let the bike cool down for a couple of hours and then took it for another blast up the hill and the problem was still there.

Any ideas of where I should start to look?

[pwrpapa]

you may have a broken tooth letting it ratchet. if the drum was bad it would jump out of gear under hard exceleration.

[Worzel]

Just to clarify, is that a broken tooth on first gear or clutch or?? I am going to pull the covers off today and see if I can see anything.

[pwrpapa]

If it only does it in first gear than it would be the gear or a bad dog ear on the gear. looks like you have to split it apart.

[Horri]

Welcome Kiwi..If you happen to find the problem post back.MY 82 XL500R does the same thing.I can't be bothered pulling it down to the box to find the cause.May do when I replace the blown base gasket..Till then I just live with it and throw it into second quick smart.

[gialinn]

this a fairly common problem with these XR/XL 500. I had the same issue. SPlit the cases and replaced both gears that engage for first. The dog ears were quite worn. It would slip in and out of gear or just come out entirely. It fixed the problem for about 1 season, now it does it again. I should have replaced with new gears (i bought used) and replaced the shift fork.

[Worzel]

Ok, sorry to say but all answers posted so far are wrong. Just to clarify, it is not slipping out of gear. It is as if a cog is jumping, which after inspecting the gears they are not.

I have found it to be the balancer chain, which looks like it has never been adjusted. The chain is so warn, that it has chewed the hardening or roller off the joining pins of the chain, most of the rollers on the chain are pitted or chewed by the cog.

All of the teeth on the gears seem to be ok, a little pitting on the faces of them, but all the edges are still nice and sharp, other than the slipping the gearbox felt good, easily changing gears and finding neutral wether hot or cold.

Hope this helps others with the same problem.

Also the cases were easier to split than I first thought.

Ciao

[Davet916]

Are the dogs not engaging fully? I know they are rounded a bit to ease slipping in but if they aren't in all the way wouldn't it be the shifter forks, that move them back and forth, being worn? Maybe there are shims causing them to not seat all the way in.

If it were mine, I'd split the cases and shift up and down while comparing how far first engages to the other gears. I've found if I spend enough time doing that, I will see what the real problem is. Those gears and dogs are beefy stuff and should last. Once you see the real problem, a solution arrives shortly. It's like the saying, 'measure twice, cut once.'

Only here it's look and look and look and look until you find yourself saying, "Oh, I see!"

Dave

[Horri]

The Balancer Chain you reckon.Have you put it back together and run it to actually confirm this theory.Seems strange to me that if it was the Balancer it would only do it in 1st.How does it manage the return to it's good position and run normally in all the other gears if the balancers all chewed up.My bike was reco'd by supposed profesionals and it's done it ever since I got it back from them,Surely they wouldn't have missed something like that.And Yes the bike doesn't jump out of gear it just sort of lurches as though its not engaging correctly as you apply the power to the drive train.

[gialinn]

I second that. The balancer chain would not cause it to slip and if it was that loose you would get alot noise and metal shavings. Let us know what you come up with when you get it running. BTW the balancer chain is before you split the cases. Did you find that issue and decide to keep going? Also in response to whoever asked about the forks. Yes, they become worn and will not fully engage the gear, accelerating wear. After view some in good condition I remember the condition of mine and realized they were fairly worn.

[fitzy]

I always put it down to the cush drive rear hub!!! as mine does it to. not always though, and only in first. It feels like the chain jumps a cog on the sprockets. I have just pulled my balance chains out and as soon as it cools down I will tell you how it goes. 41deg Celcius here today. longest hottest dry spell in history where I live:crazy: ?

[pwrpapa]

I always put it down to the cush drive rear hub!!! as mine does it to. not always though, and only in first. It feels like the chain jumps a cog on the sprockets. I have just pulled my balance chains out and as soon as it cools down I will tell you how it goes. 41deg Celcius here today. longest hottest dry spell in history where I live:crazy: ?

I would definitely check the rear hub, that's some good advice.

[Horri]

The Cush Drive rear hub..Pray tell how that could possibly be the cause.The entire hub would need to pop out for the problem to occur.Its held in with the Axle/Nut and the Swingarm...No way in hell is it anything to do with that.

[pwrpapa]

The Cush Drive rear hub..Pray tell how that could possibly be the cause.The entire hub would need to pop out for the problem to occur.Its held in with the Axle/Nut and the Swingarm...No way in hell is it anything to do with that.

It's worth a look. The ears could be broke letting it slip. I Dunno........

[Worzel]

Horri, No I have not put it back together to confirm it, but it is the only thing that it could be, the chain is very loose and has begun to disintegrate, yes there were shavings and chunks in the bottom of the motor.

When I got the bike in parts, I knew that it had been running, but was not aware of what condition it was in, the motor was together, so I thought I would not muck around with it unless I had to.

I did not split the cases initially, but through my own fault I managed to break the follower cam for the decompression lever, so when I found I was about a week away from getting one of those, I thought that I would split the cases and see what other damage there was, which is when I found out it was the balance chain.

I know that you can see the chain by removing the side cover, and when I found it loose, I tentioned it, which is when I broke the cam.

Remember that the gearbox is driven by the tensioner chain with the crank just sitting on it, the chain does not wrap around the cog on the crank, so with it being so loose and also the slipper being warn, when accelerating in first it puts a lot of pressure on that chain and therefor slips.

I will have the parts next week, and let you know what happens. Regardless of wether it is the cause of the problem or not, the chain and slipper have to be replaced. So I have my fingers crossed as everything else, gears, dog etc all look to be in good condition.

[gialinn]

With chunks, I would look to making sure the cam chain can be tightened correctly as well. If you have it split, I would still recomment replcing the gears for 1st that mesh with dog ears. Yeah, it's expesive and a pain, but do you really want to tear it down later?