KDXRIDER.NET

I need new pipe o-rings for my 91 250, with an fmf fatty pipe. FMF wants ten bucks for them with springs , for a kx 250/500. Pretty sure they will work. Should i go with that, or use a high temp. silicone instead.

sillycone works pretty damn good, if you let it set up long 'nuff

With FRP's torque ring the rings don't do much good on mine

What kind of silicone do you use wibby?

Well went outside to see if I could find the tube but it's 22* out there and I said hell with it!!!!

But I've used two types of high temp, one is just dark orange in color and the other has copper in it, I believe both work fine

Thanks. Dont want ya to freeze in that outfit!

Yeah, Rick, I kinda felt bad for Wibs . . . running out into the cold of night with those freshly waxed hamhocks, appendages flopping wildly out of those skimpy crotchless chaps <shudder!> . . .

So I went and looked at what I've used - Permatex "Ultra Black" hi-temp rtv silicone gasket maker - wait there's more . . . formador de junta de silicon rtv alta temperatura . . . geez my eyes must be going bad . . . .

I use your basic one-each black silicone. But it says 'hi temp' on it!

The pipe rings on the KDX have never seemed to do diddle. Maybe on a new pipe that FIT they would to something, but even then, I doubt it.

All it takes is one 'ding' to a pipe...and it doesn't fit like it used to.


Contrary-wise, I put some pipes on a Banshee awhile back. Ordered new o-rings for the install. Even though I lubricated the pipes before I put them on, I still had to smack the things a few good ones to get the o-rings over the cylinder collar. In that case, the pipes fit OUTside the cylinder flange (lots if not most other bikes are like that now).

On the KDX? The pipe wallers around in the exhaust considerably.

Oh..and the o-rings off the pipes I took OFF the Yamaha? They had a pretty much flat edge to them..they had BEEN squished. I haven't noticed that so much on the KDX rings.

The rings at least keep the pipe from banging around in the cylinder, so I DO use them, but as far as sealing the exhaust?

Black goo!!

A reiterate..make sure it is cured before you start the thing up. If you put on your pipe and go out riding...it will just blow out. Like Wibby said.

22º!!?? It's 18º up here!!!

That's cold for us Orygun folks on the West of the Cascades!

Jeb: OK for the name of the stuff...but what COLOR is it??

Thanks guys. The rings are there, but sloppy. Hell, they might be broke. Havent pulled the pipe off yet. Ill probably take the old rings to work, and try to match them up. Remount the pipe, and then goop the poop out of it! Hey, I rhyme. Think that'l work?

Goop it before ya mount it

cool 10-4

I usually put a nice even coat on both the head and the pipe, no need too goop the poop out of it

ok. But thats just not as funny. Should i put a little on the outside when im done?

my wife just checked on me to see why I was laughing so hard . . . then she witnessed all of the poop-gooping & mountin' going on and now I'm tryin' to calm her down!

RE: OK for the name of the stuff but what is it?
hi-temp silicone-based gasket maker, black rtv. The tube does say "made for the professional" (whatever in the world THAT'S supposed to do for me!)

Thanks jeb. Tell your wife im sorry.

Gotcha Wibby. Thanks

Yeah...the brand I use happens to be Permatex. I'd just prefer black over orange or whatever other color.

DO clean the junction up. If the headpipe/cylinder is coated with oil, baked and UNbaked on crud, I don't suppose the silicon would stick too good.

I generally give both the pipe and the cylinder a good swabbin' down with lacquer thinner. I suppose any crud cutter would work.

Don't worry about putting any on the outside. Put a decent bead around the pipe about the first o-ring. Decent? 1/4" thick. When you place the pipe in the cylinder it will make its own bead on the outside.

IF you have done any pipe tweaking for a better fit, obviously that part is already done, right? Once you put the pipe in the cylinder you don't want to be moving it back and forth to position hangers and such. Have a pretty good idea where you're going before you go there (hanger alignment), have your spring tool ready to put one of the springs on to hold the pipe in place.

Speaking of which...a MotionPro pipe spring tool sure is handy!!

^ Yep, I'm using the same exact stuff . . .

I will say I do this about once every 6 months pull the pipe clean it and use the permatex coper high temp with the old orings, nice even thin coat on the pipe and flange to were none is squished out or in. let it cure for 24hrs before riding. works like a charm.