KX Riders
Maintenance & Technical => KX250 / KX125 => Topic started by: dirk_411 on February 11, 2014, 02:34:26 PM
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Like the title says. I read a bunch of feedback on thumper talk. For the 1998 kx250 a lot of guys said the stock pipe. Any suggestions? Fmf. Pc. Dep stock? Low end to mid. Mostly ride woods
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not up on my 125-250 class. but based on ones I have ridden. woods gnarly
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from my own experience i can say that the 98 stock-pipe is a real good alrounder, for motocross , trails and woods. dep is also a great alround-pipe. feels stronger in the mid as the stock pipe and i loved it to have on my 97 kx250 . i can not speak for the fmf woods gnarly because they are not available in europe
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I used Pro Circuit for years and years on my 250s, and was always extremely happy with the increase they gave...
I haven't seen anyone use DEP around here in years...not even on the 4Ts...
but if you want off idle stump pulling low end, go with the FMF Gnarly...
http://www.fmfracing.com/Products/MX/57
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Great responses. I will take that into consideration. And as always this is for my tecate 4 with the "1851" jug 98-99 kx250. Motor im having built is going to be 310cc 5mm stroker. Anyone else feel free to chime in.
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Totally jealous! I've always wanted a tecate 4. Had a 85 t3 way back in the day. That is the reason most of my bikes are Kawasaki :P Post some pics so I have something to drool over lol
I've always ran PC pipe. Gnarly woods you lose your top end for the added lows.
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Totally jealous! I've always wanted a tecate 4. Had a 85 t3 way back in the day. That is the reason most of my bikes are Kawasaki :P Post some pics so I have something to drool over lol
I've always ran PC pipe. Gnarly woods you lose your top end for the added lows.
I never liked the gnarly woods for the same reason. Great bottom but it falls on its face in the mid to top.
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I dont have a clue how to post pics. I use a 92 top end now. I have a couple K5 hinson baskets modified to work. Right now im having a new front end being built with elka stage 5's and the yfz lonestar billet spindles that use the ltr450 geometry. Run precision stabilizer and bar mounts. Rear end being built now to, dominator axle hardkor rear hubs, everything else is lonestar billet with custom dual piston caliper and new style rotor and sprocket guards also custom made.
Shoot me an email and I will send a couple pics for ya to post up
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Send pics to:
oem-cycle@comcast.net
Send me your pics with your kxriders user name and the name of the thread you want them posted in (Best low end-mid pipe for 98 kx250) and I will post them for you.
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Here you go..
(http://www.oem-cycle.com/forum/download/file.php?id=1637)
(http://www.oem-cycle.com/forum/download/file.php?id=1638)
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(http://www.oem-cycle.com/forum/download/file.php?id=1639)
(http://www.oem-cycle.com/forum/download/file.php?id=1635)
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(http://www.oem-cycle.com/forum/download/file.php?id=1636)
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Those are some pretty quads. I am super jealous now. Cases anodized or is that blue chrome or some fancy paint? What pipe is on there now?
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Great responses. I will take that into consideration. And as always this is for my tecate 4 with the "1851" jug 98-99 kx250. Motor im having built is going to be 310cc 5mm stroker. Anyone else feel free to chime in.
Dirk,
What bore/stroke will you be running? Plus 5mm on the Tecate (75mm) or plus 5 on the KX250 (77mm)? I would be hesitant to buy a "Torque" pipe, if you are going to run a 72-74mm bore on the 1851 cylinder you lose a lot of much needed port time area. I have a 1851 with the 74mm & it added a lot of bottom end, but gave up a lot up top & with that setup I liked the FMF fatty over all of the other pipes, as it allowed the bike to have some over rev, and still had the great bottom, versus running flat.
With your stroker setup you will be able to get some of your time area back, and I think you will be impressed with the amount of torque it will have in itself.
Another question, you say you are currently running a "92" cylinder? What stroke is your current setup? The tecate stroke (if memory serves) was 70mm & the "92" cylinder was setup with a 72mm stroke.
DoldGuy
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Im building a big bore 04 KX250,290cc. In 250 form I ran a Enduro Engineering pipe which worked well across the board. Its a pretty rare pipe, seems like they only made them briefly. Ive also used a Gnarly, good low and mid but signed off a bit early. The stock pipe worked well also. What pipe would you recommend with the 290? I have a never used Pro Circuit Works pipe and have been thinking that it would work well. They seem to be a mid to top oriented pipe. Im not new here Im the Flyin Hawaiian. Ive been having trouble getting on the site so I made a new acct. up.
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Doldguy, 5mm on the tecate crank. I dont originally build these motors. I dont have the the skill per say or the proper resources. I can rebuild them myself.
That being said. The motor your looking at has the kx crank grafted into it to match the jug. The pipe is dyno made for that motor. ILR performance out in Wa. The reason I am doing a new motor all stem from the desire to have a cool head. Phat head. So after reading I decided to commit to the "1851" jug. Bought 5 of them all with PV's and 3 additional sets of new power valves. That ultimately was the reason I wanted to convert to a kx250 jug. The tecate power valves were brittle and not available.
Sounds like this motor is going to have some low end grunt by design from what you say. Perfect. I wonder if I should go for a mid-top pipe?. I run a pvl and the pulse induction system that's in the K5 threads.
Im really looking forward to the new motor. I may not have it for this summer, unsure yet. Here's a run down on whats going into it.
T4 lower end 6 speed
1851 jug, 310cc, port and polish, phat head running 50/50 blend of vp110 and 91 pump fuel
Tranny is under cut by fast by gast, NOS input and output shafts
Complete tranny and anything steel pertaining to shifting, power valve, counter balance, kick start and even the back gear off the clutch basket is gone to CV products for micro polish
Pvl ignition
K5 hinson clutch basket
Pulse induction fuel intake
Im anticipating a fun bike. My quad in the picks waxes that other T4 and im 80lbs heavier body wise than my buddy
Not to mention that ltr450 geometry with them 17" elka stage 5's. Will be 50". No problem for trail riding here. Going to be golden
That front end in the pics is the +3 set up using 08 yfz450 take offs and outfited with 16" dual rate fox's. I kept my hardkor front hubs, gafler rotors for these new lsr spindles. Original T4 shocks were 14" and s**tty single piston calipers to boot. Upgraded to custom +2 steering stem that is oversized and integrated the 250r 4 bolt frame clamp, kfx450r walsh lower bearing, precision pro model steering stabilizer and precision shock n vibe bar mounts that hold renthal fat bars. Dynamite, threw in the fasst co brass bar inserts and reduced feedback ro the hands dramatically. Bring on the stumps and rocks. The new spindles shorten up my tie rods by 1 3/4" per side. I think that will even improve feed back.
I just hyjacked my own post. Anyways fun to see a couple of yahs interested. Id have a tough time naming 10 people that are as deep into there kawasaki tecate 4 as me. Id bet the farm on it
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Those are some pretty quads. I am super jealous now. Cases anodized or is that blue chrome or some fancy paint? What pipe is on there now?
Thanks goat. Me and my best friend really enjoy these old 2 smokers. We were both born in 81. They are so rare. And furthermore we are in canada. Ive bought everyone ive ever seen (5) up here. Payed a lot of money to couriers to cart me up parts from the USA over the years. Only thing i use from the original T4's are oem palstics, frames and lower ends. Everything else is hybrid. I was 16 when I bought the first one. Blue paint. Fairly fresh there. Eluded to pipe in last post.
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Im building a big bore 04 KX250,290cc. In 250 form I ran a Enduro Engineering pipe which worked well across the board. Its a pretty rare pipe, seems like they only made them briefly. Ive also used a Gnarly, good low and mid but signed off a bit early. The stock pipe worked well also. What pipe would you recommend with the 290? I have a never used Pro Circuit Works pipe and have been thinking that it would work well. They seem to be a mid to top oriented pipe. Im not new here Im the Flyin Hawaiian. Ive been having trouble getting on the site so I made a new acct. up.
Hey flyin Hawaiian. I was told to ask you about my power valves governor spring. Im running the 98-99 jug. I was wondering if I should try to swap my stock T4's spring for the 98-99 spring? Any thoughts?
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Since you're running the kx top end I would imagine upgrading the spring would make it a bit snappier. Especially since the t4 spring is probably from the factory when it was new :P
I'm now looking for a T4 to buy lol thanks for that :P I may even leave the 250 in it since I have the quadracer with a kx500 in it already.
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Im not sure of the diameter of the T4 spring versus the 98/99 spring. I have some powervalve governor shims that I used in my 90 KX250 and they wouldnt fit my 04 gov. I cant remember if it was the diameter of the shaft or the spring itself. Im thinking that the spring from the 90/91 KX and your T4 might be comparable in size since the engines changed in 92 and went on to 04.
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Im building a big bore 04 KX250,290cc. In 250 form I ran a Enduro Engineering pipe which worked well across the board. Its a pretty rare pipe, seems like they only made them briefly. Ive also used a Gnarly, good low and mid but signed off a bit early. The stock pipe worked well also. What pipe would you recommend with the 290? I have a never used Pro Circuit Works pipe and have been thinking that it would work well. They seem to be a mid to top oriented pipe. Im not new here Im the Flyin Hawaiian. Ive been having trouble getting on the site so I made a new acct. up.
welcome back flyin hawaiian ... :-) which piston size do you use for the 290 big bore?...
i have an 96 engine bored up to 353,8 ccm.thats the absolute maximum ,you can get out of the 250 engine ... 74 stroke and 78 bore(modified piston from suzuki rm370) ..at the moment big trouble with the handmade headgasket and have to find a better solution... so i use in the moment a 03 stock cylinder with 66,4 bore on it = 270 ccm ... real great bottom -mid and little bit less top end . i plan to go to 72 bore with an old worn 95 cylinder that i have laying around. i had a 2000 gasgas ec300 and i loved this added torque that the engine made...
for the 360 engine we needed a special pipe... no kx250 pipe was working well enough ... we tried next a modified ktm sx360/380-pipe .. better,but not the best result ... at least "van hasselt" in belgium made a pipe for us. with this pipe it felt very strong from bottom to top and in direct comparing 1,5 hp more than a stock ktm sx380 on the rear wheel. ;O)
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Im not sure of the diameter of the T4 spring versus the 98/99 spring. I have some powervalve governor shims that I used in my 90 KX250 and they wouldnt fit my 04 gov. I cant remember if it was the diameter of the shaft or the spring itself. Im thinking that the spring from the 90/91 KX and your T4 might be comparable in size since the engines changed in 92 and went on to 04.
I ordered an 98-99 and an 04 governor spring. We'll see if either fit
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Let us know of your findings. I love tinkering with these engines. I shimmed the gov spring on my 07 KX250 with good results. The 07 has little in the low end with a monster hit in the midrange. Retarding the timing slightly and along with the shim helped noticeably smooth the delivery. Seemed to add a bit bottom also. Next step is having the head modded for more compression and add some more bottom. May try a APT Smart Carb too.
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Im not sure of the diameter of the T4 spring versus the 98/99 spring. I have some powervalve governor shims that I used in my 90 KX250 and they wouldnt fit my 04 gov. I cant remember if it was the diameter of the shaft or the spring itself. Im thinking that the spring from the 90/91 KX and your T4 might be comparable in size since the engines changed in 92 and went on to 04.
I ordered an 98-99 and an 04 governor spring. We'll see if either fit
ok you two have caught my interest enough to try some different setups on my 250 as well.
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ok you two have caught my interest enough to try some different setups on my 250 as well.
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EDITED. March 13/14
I stand corrected. I for some reason had it in my head that the oem power valve mechanism balls were stainless steel. They are NOT stainless. Void my reference to stainless
I found a read by eric gorr. I am not an eric gorr fan because of the one and only time I spoke to him. However I like to root through his literature, largely impart because it's everywhere on the net. So check out this brief read regarding the power valve governor mechanism. It really sheds light on the possibility of combinations. I have tons of tecate 4 PV gov. mechanism spares. If anyone wants to exchange spares and do a little R&D let me know. I would have endless combinations of KX parts to try. Im kind of thinking if im running the "1851" jug I should start first with those parts. After all im am essentially running the KX jugs for there improved performance over the T4 jug, and parts availability. It could be entire mechanism swap or parts and pieces. I understood the centrifugal operating principle but never pondered changing springs, ramps and SS balls. Very interesting none the less. Im thinking of playing with combinations on my current motor and then build this into my new motor. I like the fact I sent the gov mechanisms shaft, ramp and cup for micro polish
The exhaust valves are opened and closed by a centrifugal governor mechanism. The governor is mounted under the right side cover and is gear-driven by the crankshaft. As the engine rpm increases, the governor spins, thereby increasing the angular momentum of the four steel balls encased in the governor. The steel balls fit into an angled ramp-and-cup arrangement. A spring is used to provide tension on the steel balls. When the momentum of the steel balls overcomes the spring’s tension, and the balls force their way up the angled ramp. A spool attached to the ramp, enabling it to change its linear position with changes in rpm, and the spool is attached to a linkage system that operates the exhaust valves in the cylinder. Factory race teams have different combinations of springs, ramps, and balls to tune the exhaust valve operation and enhance the powerband.
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good write up, more info on the governor than I was aware of...I'm looking forward to experimenting on mine, but it won't be for a couple months, til the weather gets better/warmer...we have nearly 20" of snow on the ground right now and it's a balmy 14F :-(.
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Same here man.
The Tecate 4 governor spring is used and is measured removed from the mechanism.
Height 24.05mm
Width 25.30mm
Washers/bearings measured around 27.97mm
Stainless steel balls I believe are 5/16"
Would I be correct in saying the weight of balls and the rate of the spring effectively determine when the power valves operate? If you went to heavier SS balls and a softer spring basically your PV's would operate at a lesser RPM? OR lighter SS balls and heavier spring rate they would operate at a higher RPM? Am I correct?
If anyone can throw the kx250 and the kx500 measurements at me that would be great. Include year and model
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I think you're theory is spot on...it could be tricky finding SS balls that are the same diameter(for clearance in the governor reasons) that are heavier/denser...but as you stated, spring rate will play a major role in that also.
Very interesting.
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After taking a look I noticed that the majority of kx250's used 3/8" SS balls. There were a few kx250's in the late 80's to mid 90's that used the same 5/16" as my tecate 4. I guess the next thing would be to know the weight difference between the 2 SS balls and the spring rate between my T4 and the various model kx250's. I think im going to start with the 98-99 kx250 governor mechanism and see what can exchange
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Good info. Now I want to play around with my 500 and kdx governor. I'm in the same boat as Fox with a ton of snow on the ground and really cold temps.
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Me too. 4 feet of snow and -20ºc. Any R&D im doing will be online and in my basement, till april or so
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Good info. Now I want to play around with my 500 and kdx governor. I'm in the same boat as Fox with a ton of snow on the ground and really cold temps.
glad to see I'm not the only one in the frozen tundra :-D...
Me too. 4 feet of snow and -20ºc. Any R&D im doing will be online and in my basement, till april or so
4 feet!!...d**n, I thought I had a lot at 20ish inches...although we're expecting another 4"-6" tomorrow :x
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Same here man.
The Tecate 4 governor spring is used and is measured removed from the mechanism.
Height 24.05mm
Width 25.30mm
Washers/bearings measured around 27.97mm
Stainless steel balls I believe are 5/16"
Would I be correct in saying the weight of balls and the rate of the spring effectively determine when the power valves operate? If you went to heavier SS balls and a softer spring basically your PV's would operate at a lesser RPM? OR lighter SS balls and heavier spring rate they would operate at a higher RPM? Am I correct?
If anyone can throw the kx250 and the kx500 measurements at me that would be great. Include year and model
I just scoured through my 250 Kawie manual hoping to find some specs on the governor parts...but nothing at all...just pics...and the same with my 500 manual, nothing but pics.
Not sure if a Clymer would give any specs...otherwise I'll have to wait and see if anyone else has any extras floating around to get measurements. :|
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I doubt you will find any specs via manuals. I Just bought a 99 gov mechanism $20 total shipped into Canada. I should know whats happening in the next week and a half
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if I get the chance before Friday, I'll swing over to my Kawie dealer and see if he can order an entire new governor...even if it has to be done all in parts/pieces.
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If you wanna pay shipping I can send the complete tecate 4 set up. Appears to be similar to the late 80's to mid 90's kx250's. 5/16" SS balls. Im really interested to see if the tecate 4's cup and ramp pieces are a direct swap to the kx ones. I see the tecate 3's or atleast a few model years use the 3/8" ball too
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let me see if I can get over to my dealer 1st, because after Friday, I'm gonna be laid up for 3-4 weeks from "big" surgery on re-occurring hernia...pretty much the whole front of me is getting sliced open, and getting a big piece of mesh laid into place, after they yank all the muscle back into place :x ....needless to say, I'm not gonna be able to do much of anything, besides take pain pills and drink :|
but after I've recovered, I'll definitely cover the shipping if you wanna send me the parts for comparison.
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I'm gonna be laid up for 3-4 weeks from "big" surgery on re-occurring hernia...pretty much the whole front of me is getting sliced open, and getting a big piece of mesh laid into place, after they yank all the muscle back into place :x
Cool!
Have a nurse snap a few pics and post them for us :-D
And, hope everything gets back to normal soon..
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Thanks...
I'm not looking forward to it at all...my doc warned me that going this route is going to be very painful, but there would only be a 5% chance of it re-occurring again...versus an 80% chance of it re-occurring again if he just fixed the immediate problem area....so it was kind of a no brainer which way to go...I'll be in the hospital either side of 3 days.
I'll take a pic of the scar once I can remove the bandages, which will probably be pretty long...but I don't do well with blood and guts...especially when it's my own :-(
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I doubt you will find any specs via manuals. I Just bought a 99 gov mechanism $20 total shipped into Canada. I should know whats happening in the next week and a half
now that you mention it, there are no part #s for any pieces of the governor in the manuals or on line...so, I'm wondering if it's even possible for us to buy new...I'll definitely swing over to my Kawie dealer tomorrow and find out.
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Go to buykawasaki.com and view parts diagrams. They have got part numbers for everything. Just a matter of what's available. The bearings and washers will be available. It will be stuff like the shaft, cup and ramp that probally wont be available for a lot of older machines. But you nevef know it could be current yet
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Just looked in my clymer manual. It has a parts diagram but i couldn't find part numbers anywhere. I'll call around and see where I can find springs other than the kawi dealer. Speed shops should have an assortment of springs, washers, bushings ect.
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ok, I found everything. The COMPLETE governor piece by piece goes for $192...that's through Rocky Mountain...I should be able to get it closer to $150 with my discount at my Kawie dealer.
That's for my 2000 L2 250.
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Should really check out ebay
You could buy 10 for that price. In reality you actually could buy probally 5 different set ups from specific models and be covered with most parts to use in tests. It doesnt appear as though there is dozens of combinations. When you start looking at the mechanisms that use either 5/16" or 3/8" SS balls and cross reference those parts (cup, shaft, ramp and balls) it shows a lot of models and makes of kawasaki power sports use the same parts, more so the 3/8". Thats why I say if you did a little research you could likely narrow it down to about 5 different mechanisms and have yourself covered. I think for myself its going to be quick and painless. If the parts swap out then its a matter of me upgrading to the 3/8" hardware and matching spring. That in it's self should be noticeable. Im not sure if going larger than 3/8 SS balls is even possible without enlarging the ramp. The other thing is what other metal balls could you use to increase or decrease weight? I like stainless because of its anti corrosion properties. I read if your spring rate is to stiff you nullify the PV's
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I hear ya...I just wanted an idea of what it would cost new....I'm not gonna do anything until after my hospital visit, then I may decide to buy one complete new set-up and pick up a few off e-bay as well.
Can you get BBs in different sizes?...I wonder if they would have the density/weight...or if they're made out of metal strong enough.
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I was thinking about going to my driveline shop and buying a couple bearings to cut apart and see what the balls weigh. BBs are a good idea as well. I have seen some in ceramic at some point but not sure what they would weigh compared to ss. Copper coated ones would probably be ok but I think those are too small in diameter. Airsoft might last for a minute but seem to be too light.
We just got another 8ish inches of snow last night. Time to bust out the kdx/quadracer with paddles n skis :P
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I was thinking about going to my driveline shop and buying a couple bearings to cut apart and see what the balls weigh. BBs are a good idea as well. I have seen some in ceramic at some point but not sure what they would weigh compared to ss. Copper coated ones would probably be ok but I think those are too small in diameter. Airsoft might last for a minute but seem to be too light.
We just got another 8ish inches of snow last night. Time to bust out the kdx/quadracer with paddles n skis :P
All good ideas/thoughts...I never thought of the ceramics, they'd probably be quite a bit on the light side compared to ss.
Just starting to flurry here.
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motopunk, 72 on the piston.
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Goat. Interesting idea. Post your findings. I took apart a spare mechanism and the ramp is built for the 5/16" balls only. So if a full swap is not available then I suppose I could remove material off the ramp and accommodate a larger ball. That would be 2nd worse case. Worse being cant make any moves
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motopunk, 72 on the piston.
ok. same size, that i also want to go .. could the stock head gasket being modified?
on my 360 engine, we had to made an o-ring for the outside and a copper ring on the inside.. there is very less space to the studs like you could see it in the pic. left is the 360 with 78mm bore, right is 03 250 cylinder...
(http://img.webme.com/pic/d/der-motopunk/foto0009.jpg)
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Cometic makes a head gasket for the BB so no modifying of head gaskets. I should have it back in about 2 weeks and Ill post up the part # for it.
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Cometic makes a head gasket for the BB so no modifying of head gaskets. I should have it back in about 2 weeks and Ill post up the part # for it.
great info... that would help me a lot, when i realize it..
just found this...is it the kit,that you talked from??
http://www.shopengineparts.com/parts.aspx?eid=1146&cid=48&type=model&vtype=Dirt&make=Kawasaki&model=KX250+.010%22+SS+Head+-+%2894-00%29
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I recieved my 99 governor mechanism. It is larger than my T4's mechanism. Not a direct swap. The spring appears to be a direct swap thats about it. Im wondering if id be further ahead to see if I can fine a more dense material than SS and juwt replace my oem 5/16" balls?
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I just ordered 4 tungsten carbide 5/16" balls grade 25. Almost $16 apiece. They are more than twice the weight and have great wear characteristics.
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Wow that's expensive. I'm curious to know how they work. I didn't realize tungsten was that much heavier.
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When I get them I will weigh kawasaki's 5/16" & 3/8" for baseline numbers and then see where exactly the tungsten fits in. I will have to try them with my stock spring then try the 98-99 kx250 spring and see from there
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I got my 5/16" tungsten carbide balls. I weighed all 3. I didnt any precise way of weighing these. I used my wifes digital kitchen scale.
5/16" stainless steel- 2 grams
5/16" tungsten carbide- 4 grams
3/8" stainless steel- 4 grams
So for me on my tecate 4 with the "1851" jug I think its a no brainer. Im going to run the tungsten carbide balls and oppose it with the kx250 governor spring. I've essentially better simulated the the kx250 power valve characteristics which I feel better compliment the kx250 mod on my quad.
Now im going to see which kawasaki power sport machines use the 5/16" set up and maybe look into ramp and cup swaps. Stay tuned
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There you have it...
The weight of tungsten carbide is from 1-1/2 to 2 times the weight of carbon steel...
Nice job 8-)
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cool...thanks for sharing dirk.
can I ask where you ordered the tungsten balls from?
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www.precisionballs.com 1-800-322-5832
In Cali I believe. If you have technical questions talk to Eugene.
He told me tungsten carbide was really the only other option because of it's wear properties
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awesome...thanks for sharing that!!
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I stand corrected. I for some reason had it in my head that the oem power valve mechanism balls were stainless steel. They are NOT stainless. Void my reference to stainless
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I stand corrected. I for some reason had it in my head that the oem power valve mechanism balls were stainless steel. They are NOT stainless. Void my reference to stainless
ahh....have you been able to determine what they are?
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I hate to bring this one back from the dead, but the last couple pages are directly dealing with what I'm working with....
Does anyone know the result of running a '99 power valve governor with a '00 engine? The later model appears to have a slightly larger diameter. I ask because I bought a replacement inner clutch cover for my '00. I thought they were all the same, but my '00 governor is a bit too large to fit inside the inner clutch cover. Trying to decide if I should get the correct inner clutch cover or if I can just swap over to the '99 governor (cheaper).
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Trying to decide if I should get the correct inner clutch cover or if I can just swap over to the '99 governor (cheaper).
Besides, your 99 governor already shipped :lol: