first impressions: kdx240

bills442

Member
May 4, 2001
42
0
Greetings fellow dirt riders and kdx riders.

Well, here in rainy, grey Ohio we had a freakish 55 degree day in the middle of January this Sunday. Of course my riding partner and I loaded up the rusty 86 chevy ( Oh, thats another great feature of Ohio -- your vehicles are destroyed by salt ) for a day of riding at Wellsville, OH.

I sent my cylinder out to Eric Gorr to have a L.A. Sleeve 240 kit installed, and a "more low-mid" porting job. Previously my bike was a stock 200 with FMF k-30 REV pipe and turbine core silencer.

Eric was very fast on the turnaround of the cylinder. Only "things" I noticed were: the cylinder head water jacket was installed backwards, there was a few gasket fragments left on the head that I had to scrape off, and the final one I have not looked into yet -- but it appears that the ignition side of my KIPS valve is experiencing lot of blowby as there is a black stain on the cylinder around it. I'm wondering if maybe Eric forgot to ut a gasket on it?, but I havn't checked yet. I am happy with the work, speed and price Eric performed overall.

While I am sure the bike needs jetted after these significant modifications, here are my impressions after break-in anyway:

The bike makes an incredible amount of low end power now. It starts easily and has good throttle response. There is a very mild surge in the midrange. It feels to make almost xr400 like bottom end. The bike just signs off and hits a brick wall before the mid range is even over though. In my opinion the power gained does down low clearly does not make up for the *complete* loss of any top end. Many threads I have read suggest that it is the k-30 that is causing this "brick wall" sign off behavior. This may be so. Unfortunately I don't have the REV pipe anymore to do a comparison. I may buy another one though. Right now, if I wanted to do a quick moto I would feel very intimidated to try it now, because the bike seem so slow. The bike is a SUPERIOR hare scrambles machine now, and that is why I did these mods. I don't need the top end, I just sort of missed it.
 

bills442

Member
May 4, 2001
42
0
correction

Indeed it is. I neglected to mention that I am now running the K-35, and I miss named it in my latter paragraph. What I meant to say was that many threads I have read suggest that the k-35 causes the abrupt sign-off.
 

dhoward

LIFETIME SPONSOR
Feb 7, 2000
452
2
I've not noticed an "abrupt sign off" on my stock 200 w/KG-35. Perhaps a little more jetting work? Did Eric give you any ideas on jetting? KIPS timing ok?
 

bills442

Member
May 4, 2001
42
0
I havn't talked with Eric about jetting changes yet. I need a good shop manual to adjust my KIPS timing I reckon. I just re-assembled everything in exactly the same spots as when it came apart - hoping that would be sufficient.

It sounds like that may just be the performance characteristics of that pipe.
 

dirt bike dave

Sponsoring Member
May 3, 2000
5,348
3
My old '84 with a 240 ran exactly like you decsribe your bike. Once I got it jetted right it had a ton of low end power - I mean WAY down low, right off idle, pull 2nd gear up a cliff like an open bike - that kind of lowend.

But it fell flat on its face when the revs increased. I'm sure the stock 200cc made more peak power and revved a LOT higher than my old 240. Plus the 240 sucked down a lot more fuel.

I hope you can get yours running how you want it to, but it may require porting the cylinder for more top end.
 
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