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Fork locked up, and RM250 interchangeability question

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I knew the forks on my 87 RM250 were going to need a rebuild soon because I was collecting some dirt around the seals, but yesterday was a surprise.

We've been riding a super technical trail, and I was about a mile or so from the end when my front suspension totally locked up. They were stuck at about 2/3 compressed, and had no movement at all. I rode slowly the rest of the way out. I pulled them off the bike when I got it home, and one side is OK but the other is siezed.

My biggest question is what to do? What are the chances of these being salvageable? I'm guessing it's probably the bushings, and if so the chrome rod is probably trashed?

Should I just start looking for a good used set? Anyone know if any inverted forks will bolt up?

Thanks.

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How about a set of 89 RM conventional forks for $50.00 plus shipping? Includes triple clamps.

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Thanks, maybe. What kind of condition are they in? I thought 89 was the first year of USD's on RM's?

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89 was the last year of conventionals and are 46mm. If you go inverted you will need the clamps, wheel, axle, spacers and probably the caliper. I think your wheel, axle, caliper & spacers will fit the 89 forks. They are in decent shape...don't appear to be leaking. I've had them for about 3 years. Was going to use them for parts but never messed with them.

Make me an offer and they will probably be yours! Shipping will be in the area of $25.00.

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89 was the last year of conventionals until 98, when they were re-introduced for one year.

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89 was the last year of conventionals until 98, when they were re-introduced for one year.

Wrong.... Suzuki put conventionals on Rm250 in 96-98

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So I worked on it last night. I put a bar clamp over the length of it to keep the cap from flying off as I backed it off, unscrewed the cap and released the preload with minimal fanfare. Once that was loose, I dumped the oil and flushed a couple times with solvent. A couple light hits with the lead hammer, and it was free.

Here's my new problem: the Clymer manual says you can change the seals without having to remove the cartridge from the base. All you need to do is remove the retaining ring from the dust seal, and use the inner tube as a slide hammer to knock the bushing, seal, and dust seal out the top of the outer tube. I tried this for a while, and nothing seemed to be budging at all.

Is it true you don't have to remove the bottom cartridge to change the seals on these forks? I talked with a local shop and ran a few searches, all of which disagreed with the manual. All said you do have to remove the bottom cartridge.

Thanks all.

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You did remove the spring and the cap from the rod, right? Just heat the area around the outside of where the seal goes in and then "slide-hammer" them apart. If properly heated it will come apart very easily.

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The 1989 125 used 46mm conventionals. The 250 had inverted.

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Yeah, I removed the cap. I did heat it with my heat gun, but did not take the blowtorch to it. Can you describe "proper" heating?

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Uhhh? About 30 secs of map gas worked on these today...then just knocked them right apart. Just keeping going around the outer tube.

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Uhhh? About 30 secs of map gas worked on these today...then just knocked them right apart. Just keeping going around the outer tube.

OK, that's a lot more aggressive than I got. It looks like the forks are anodized or clearcoated, which is why I was hesitant to use more than the heat gun. I assume if it survives MAPP gas, a propane torch won't mess it up.

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my indication for the correct heat is a 'touch test'

if it starts burning my fingers when touching the tube, it's already too hot :thumbsup:

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