97 KX 250 needs torque

[richep]

I ride my 97 kx 250 in some real nasty slow speed stuff and it never seems to have enough low speed power. I have the heaviest flywheel weight, Knarly pipe, running 12t front sprocket which limits my top speed to nothing and I am in search of the next add on. I always liked the kdx motors but I won't part with the kx because I love how it handles. Jetting is almost perfect for season, so I'm thinking reeds next. Which reeds give most torque? This bike is a rocket on top end. Ant other ideas? Thanks.

[hi_im_sean]

you need a hybrid

[97 Polaris Ultra SPX]

^^^

Yea, get a kx 125 roller and put a kdx 200 motor in it.

[richep]

Just don't have the time or funds for a project like that.

[jzook]

I've never tried them but I've heard that aftermarket low tension reeds improve throttle response.

You can also get a thicker reed block spacer which is also supposed to increase low end power.

http://www.motobargain.com/pk4/store.pl?view_product=381

[CR480R]

More compression... More timing...

[Jeekinz]

That's weird because those bikes are nothing but torque. What rear sprocket are your runing? When was the last time you did a top end and serviced the powervalve?

[MJP68]

im confused, the 97 KX250 was bike of the year based on its low to mid power. i used stock gearing at the dunes with a paddle and never wanted more low end.

like jeekinz said how fresh is the top end??

[seehogs]

Find a Radvalve and raise compression a little.

[richep]

Top end was fresh when I bought it last summer. Has tons of compression. I think this bike was raced MX for a while and though it was treated and maintained well, I wonder if it was modified to have more top end. In 5 gear cruising along, if I roll the throttle it takes off like no other 2 stroke I've ridden. I raced my buddies KX450F and can smoke him through 5 gear, after that he blows by me. Maybe i'l change the reeds. Also, it came with 13/48 gearing. I'm running 12/48 now.

[beamishnz]

I run 13/50 and find that perfect and regularly use 1st & 2nd on the tight stuff - Mainly 2nd. 12/48 makes 2nd gear too high for the tight stuff so end up using mainly 1st which is too twitchy and if you try 2nd you are reving too low. Just mey experience.

I run v force reeds, Gnarly pipe, Shorty and 10oz FWW and all these things help.

[makKX250]

+2 for the powervalve. If it is stuck open the low end will suffer. Can you pull the cover and see if it is operating?

[MJP68]

i have to agree with the power valve theory, sounds like it may be stuck open.

[richep]

Hate to dig up an old thread but I have my bike all apart for a repaint and figured I would look into the power valve and see if it was working. When I took off the side cover I noticed the pin on the arm coming from the bottom end was not in the slot as it supposed to be. This was keeping the powervalve from closing. Can't wait to get it back together and try it. You guys were right.

[Jeekinz]

Hate to dig up an old thread but I have my bike all apart for a repaint and figured I would look into the power valve and see if it was working. When I took off the side cover I noticed the pin on the arm coming from the bottom end was not in the slot as it supposed to be. This was keeping the powervalve from closing. Can't wait to get it back together and try it. You guys were right.

That means someone not familliar with Kawie's put the top end together. You can sneak it in by loosening the base nuts and repositioning. If you have the money, I would just put a new top end and gasket kit on her, service the powervalve at the same time. Then you're done with it.

The person you bought it from may have tried to compensate for that, so check the jets and ignition timing. It's probobly why he sold the bike. lol

[Polar_Bus]

I ride my 97 kx 250 in some real nasty slow speed stuff and it never seems to have enough low speed power. I have the heaviest flywheel weight, Knarly pipe, running 12t front sprocket which limits my top speed to nothing and I am in search of the next add on. I always liked the kdx motors but I won't part with the kx because I love how it handles. Jetting is almost perfect for season, so I'm thinking reeds next. Which reeds give most torque? This bike is a rocket on top end. Ant other ideas? Thanks.

You have major mechanical issues with your KX250.

I raced a brand new '97 KX250, and that engine was the pinnacle of brutal KX hp (bike was voted bike of the year by Dirt Bike mag. by virtue of shear HP alone). The fastest 250cc in '97 PERIOD... How about instead of all the zoot hp mods, doing a fresh top end rebuild?

[richep]

If you read two replies up, you'll see I found the problem. The top end was done last summer before I bought it and that was when the powervalve arm was no lined up right. How do the 97's power stack up to the later 250 2strokes?

[treelimb]

did you know that a 1997 kx 250 has almost but not quite twice the hp of a 1997 KDX 200? that ain't nothing man.I'll keep my low hp KDX 200 and hit treelimbs w/the best of 'em. hp has never meant a thing unless you are looking for speed,low end,mid range,hill climbing,drag racing 4 strokes,drag racing other 2 smokes,racing mx,racing enduros,racing hare scrambles,not racing at all but just riding around looking for sh-- to jump(that's what I do),and all that. so in other words,if you don't do any of the prior mentioned stuff,what good is hp?

[sclifton]

Treelimb is rite buy a KDX if you want to ride the nasty tite stuff. I love mine it will go anywhere with out cluthing it all over. Sounds like you know alot more about bikes than I do but have you thought about using a torque ring?

[treelimb]

hey clifty.don't get me wrong because i would love the huge hp. I would not know how to deal with it. The guys w/all that hp do and i guess they miss it.It BOGGLES my mind simply because of how my half as powerful(maybe not half due to my mods) still scares the hell out of me on ocassion and could not envision the hp of a modded kx250.

I like their need for more bike though.People claim I ride like an idiot and too fast.can't imagine having a bike w/even more output.I'd like to experience it once or twice though.