Chamber Supports - what am I missing?

Discussion specific to the 1991 - 1994 KDX250 sold in the USA
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dingerjunkie
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Chamber Supports - what am I missing?

Post by dingerjunkie »

Hello All.

Getting ready to do a fit-check on the FMF Gold Series I picked up for the 250. All seems right, up to the point that I go to attach my new elastomer/anti-vibe mounts.

There is no problem with the rear mount...
Image

...but the front mount seems to be off. First, if I line up the shock mount with the "guide rails" on the frame cradle, the bolt point for the chamber is nowhere near fitting. If I grind off those rails, the elastomer piece still sits nearly an inch away from the cradle when bolted into the chamber.

Image

I confirmed that this is the right pipe for the model with FMF, and I've also double-checked the part number for the elastomer piece. The original bike, which came with a crushed FMF chamber, did not have a front shock mount in place.

Can anyone show me pics of your installation if you have an FMF on your 250-D series?
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Re: Chamber Supports - what am I missing?

Post by Dekon »

I find FMF pipes do not fit well. I have a FMF on my '89 200, and the mounts are off a bit. When I fit mine, I made sure the pipe was in the cylinder as best as could be, put the springs on it, and then attached it to the silencer. Then I cursed and cursed some more as I tried to put the rubber pipe mounts into place. The one under the pipe near the cylinder was a real PITA to get on.
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Re: Chamber Supports - what am I missing?

Post by 6 Riders »

Make sure that you don't have ANY bolts tightened down until they are all in place. I made this simple mistake while working on my son's bike....even a stock pipe will not bolt up if any one of the mounts are tightened down before they are all fitted. Just set the pipe into the silence and cylinder and then hand fit the two bolt to the frame, then you can tighten the bolts down evenly.
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Re: Chamber Supports - what am I missing?

Post by royadams »

Image[/URL] [/img]
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Re: Chamber Supports - what am I missing?

Post by royadams »

royadams wrote:Image[/URL] [/img]
I had no issues with the pipe fitting on mine. i would loosen it up and see if it move around bit.
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Chamber Supports - what am I missing?

Post by dingerjunkie »

Thanks for the pics, royadams.

What I'm noticing in your pic is that the shock mount is not in-line with the frame rail.

If you look at my shot, I've been trying to get that mount into the "guides" you see on the frame. On yours (though I couldn't zoom in really well), it looks like you connected to something other than the lower bolt point for the front engine mount (where mine almost lines up). Is there another piece there, or are you using a different elastomer mount than I'm trying to use?

I'll PM you offline with questions about the fork guards...very nice bike.
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Re: Chamber Supports - what am I missing?

Post by royadams »

Its all the factory mounts. Wish I could help you more, but I built a hybrid with that engine and do not have any better pics. Those fork guards came off of a 2000 kx 250. I believe I had to drill one new hole wear the side bolt goes.
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Re: Chamber Supports - what am I missing?

Post by royadams »

I see your problem now. The mount is missing on your frame.
Image[/URL] [/img].
This is the engine cradle off of my kdx250 i grafted in .
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Chamber Supports - what am I missing?

Post by dingerjunkie »

Aha! Okay. My bet is that the previous owner sheared that off when the previously-installed FMF pipe got crushed and pushed rearward.

So, this means stripping the paint from this area...again...and additional welding. DAMMIT!
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Chamber Supports - what am I missing?

Post by cornishwrecker220 »

Rather than weld a tab back on & ruin that lovely fresh paint would it not be easier to machine up a spacer & mount it via the lower engine mount bolt hole ( on the frame )...From the pic it doesn't look too far off & with a few small minor tweeks could work ??
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Chamber Supports - what am I missing?

Post by dingerjunkie »

There is a possibility. I could likely machine a piece that bolts into the outside of the motor mount point and runs between the two remaining tabs. This could then be drilled and tapped at the point of the original mounting position.

I'll see how ingenuitive/motivated I get.
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Re: Chamber Supports - what am I missing?

Post by KDXGarage »

If it helps any, the part you have at 12 o'clock seems to be at 9 o'clock on the diagram.

I thought you bought a 2nd frame??

Image

After some researching, look at 25 - 30 seconds in this video.
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Chamber Supports - what am I missing?

Post by dingerjunkie »

I did buy a second frame. The first one had destroyed seat tabs and torched-off rear fender support mounts. I didn't realize the second one was missing this front exhaust mount point/tab.

I can easily cut the tab off of the old frame and mount it to the new frame...just bummed about the prep/re-work to the frame after refinishing. Given that this will be a relatively low-pressure position, I may epoxy the old mount onto the remaining tabs on this frame to avoid disassembly/paint-strip/weld/repaint effort.
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Re: Chamber Supports - what am I missing?

Post by KDXGarage »

Bite the bullet....

you have come this far....


so close now...

:partyman:
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Re: Chamber Supports - what am I missing?

Post by KDXGarage »

What did you end up doing on the pipe mount?
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Re: Chamber Supports - what am I missing?

Post by dingerjunkie »

Given past exposure to how well bonding agents work (e.g.: DR350 swingam manufacture), I decided to clean up the existing tab points, file clean the unit off the other frame, high-strength epoxy and touch up paint locally. The garage is currently below freezing (-4 actual outside yesterday morning), so I'll wait until I can get an ambient temperature that will allow for proper curing. You'll see pics once complete.
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Re: Chamber Supports - what am I missing?

Post by KDXGarage »

OK, thanks for the report.

Stay warm! :grin:
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