To pipe or not to pipe

[MARC]

will be as brief with this one as possible. Considering a rev pipe for my 01 200. Have read here that the stock pipe uses double wall constrction to reduce noise. I suspect it is also for another reason. The kdx is meant to be ridden at a variety of speeds, not just flat out high rpm racing, and because of this, the double wall pipe construction most likely is also done to help the bike from "falling off the pipe" too easy by retaining the expansion chamber heat better. If not familiar with this term, it basicly means, when you slow the motor down, the pipe cools slightly, if it cools too much the motor will tend to miss or sputter slightly for a few seconds when you get back on the gas untill the expansion chamber heat comes back up. My only experience with this problem however has been with putting aftermarket pipes on snowmobiles operating in much colder temps and not bikes, so I dont know what to expect here. The situation can be quite annoying, and Im not interested in wrapping the pipe to get rid of the problem. My question is, has anyone noticed after putting the new single wall construction aftermarket pipe on that the motor tends to be more finicky, and tends to miss or sputter for a few seconds after you have slowed down and then get back on it, or has it not been a problem?

 

[Cactus Jim]

Marc.... The KDX is one of the few bikes on the planet that comes with a double wall pipe. Although I don't ride in really cold weather, with the bike jetted right, I've never noticed any sputtering at all, or any problems from "pipe cooling". To the contrary, with the Pro Circuit pipe and the Boyesen Power reeds, I've noticed a substantial increase in power throughout the range, with most of it mid to upper. Since you have a 200, if you want power at lower RPMs, you could go with the FMF "Woods" pipe. It all depends on what type of riding you do. I really think the reason for the double wall construction is strength. The stock pipe is very strong!!

 

[Tantrum]

What he said.

Also, the FMF Gnarly, aka KG-35, is made of 18 guage steel. It is thicker than most other aftermarket pipes. If you managed to dent the boat anchor that is your existing stock pipe, you will need a thicker pipe. Or get a pipe guard.

BTW, you will shave a couple pounds off the bike be getting rid of that exhaust system as well as haul ass on the trails. :)

B.

 

[Mac]

If your spending the cash for a new pipe then spend some more and get a pipe guard. It will not only protect your new investment but will help retain some heat. It will also help protect you leg from burns in case you lay the bike over.

 

[jeffw]

Marc,
You will not believe the low end you get from a KG-35. My bike now feels like my friends GAS GAS 300 down low, no kidding. I can grunt through almost any nasty spot now where with the stock pipe I'd have to clutch it back into the power and then had wheel spin problems, with the associated lack of control. You'll probably want a pipe guard, The FRP guard is fiberglass which is an insulater, of course, and will keep the pipe temp up. The stock pipe weighs at least 10 pounds and the FMF pipes weigh half that.

 

[canyncarvr]

..the motor tends to be more finicky

This is true of any engine that is put into a 'higher state' of tune. Loading up in low rpm/low demand situations isn't uncommon to a tweaked (basically modified) kdx. The benefits of the tweaking far outweigh the downside of being 'finicky'.

re: FmF pipes in general

Forget the woods/gnarly/burly/desert stuff. FmF makes two pipes for the later 200/220s, a kg-30 (rev) and a kg-35(torque). Those model numbers are stamped on the mounting flange of the pipe. They are both 18ga. (BTW a K30/35..no 'g' is 19ga. You might find that in an older, used pipe).

Oh...the fact that some catalogs call the kg30 for the 220 a 'torque' pipe notwithstanding, the model numbers are as listed.;)

 

[MARC]

appreciate the input so far. The practice of double walling pipes or putting heat sheilds on, has been a trick used for a number of years by the sled builders on their high perf. models to reatain the heat so they run more consistently and dont fall off the pipe, so naturally when I see it done on the pipe for the kdx I assume the folks at Kawi have also learned something here and are doing it for the same reason. From what I gather so far, running in the considerably warmer temps you are likely to see when on a bike, putting on an aftermarket pipe has not posed any major problems, but anyone else willing to throw in their 2 cents worth is welcome to reply.... Thanks

 

[vandean]

Will a Kg-35 really add that much more low end power?
I personally need to spend the money fixing my front end problems first however adding a little more to this tractor still sounds attractive!

 

[Sage]

Silly rabbit, pipes are for kids (who want their KDX's to run!!!)

 

[canyncarvr]

marc:
I doubt any kdx rider with a pipe guard has given any thought to heat retention, or has put it there with anything sleds have to worry much about.

In a word, flying ROCKS. Well..and falling down....on ROCKS.

It kinda stinks to have $170 or so in a new shiney pipe only to put a big DING in it. Talk about something that's going to hurt 2-stroke performance!!! A pipe with a pressure wave pattern that's hose'eh'vued due to 'reshaping'.:(

 

[G. Gearloose]

Originally posted by MARC
so naturally when I see it done on the pipe for the kdx I assume the folks at Kawi have also learned something here and are doing it for the same reason. <snip>

Kawi still hasn't learned how to jet, nor grease the bearings and bushings in their products, I don't think they put THAT kind of science into their pipe.

 

[MARC]

o.k. nuff said about pipes, sounds like aftermarket results worth the jing. Now I've got some dumb questions about tranny oil. go to: what's the deal with the tranny oil?