KDX 200 Grand Prix tuned.
- Thread starter BroLy
- Start date
Now that's MY kind of KDX :)
If it goes half as good as it looks it must be a monster.
If it goes half as good as it looks it must be a monster.
- Oct 13, 1999
- 2,807
- 0
fatty - I doubt the clutch uses that much hp, but the clutch, transmission and final drive all contribute frictional losses. Horsepower measured at the flywheel (crankshaft) will always be greater than hp measured at the rear wheel.
- Thread starter
- #8
Believe it guys, this bike was preparated by a very known Portuguese 125 GP Nacional preparator, the behavior of the engine doesn't have nothing about KDX 200 stock engine.
Now it looks like an GP 125 bike, but with more torque and power @ crankcase.
Jpm200, indeed, the engine uses now a longer connecting rod from KTM 200 00' model with the double of the stroke for getting a better top-end power and to get a connecting rod/crankcase attack angle of 76º like the MotoGP 2-stroke ones.
Woodsrider, believe me my friend, we now bought a CR 250 of 2002 (~60 hp) stock, with a final transmission of 14 - 48 who gives a real velocity of 129 km/h, and comparising the 2 bikes here in the little streets, the KDX 200 is equal to CR 250 in detonation, but when the CR 250 ends @ 130 km/h +/- the KDX goes only on 4th gear and goes away very fast..
Oh, I forgot to mention that the bike does real 186 km/h...
You can check it out on the end of this page, the table of the transmission and gear ratios and the formula to get the real velocity :)
http://www.racingsm.org/motorkdx.htm
Hf guys ;)
Now it looks like an GP 125 bike, but with more torque and power @ crankcase.
Jpm200, indeed, the engine uses now a longer connecting rod from KTM 200 00' model with the double of the stroke for getting a better top-end power and to get a connecting rod/crankcase attack angle of 76º like the MotoGP 2-stroke ones.
Woodsrider, believe me my friend, we now bought a CR 250 of 2002 (~60 hp) stock, with a final transmission of 14 - 48 who gives a real velocity of 129 km/h, and comparising the 2 bikes here in the little streets, the KDX 200 is equal to CR 250 in detonation, but when the CR 250 ends @ 130 km/h +/- the KDX goes only on 4th gear and goes away very fast..
Oh, I forgot to mention that the bike does real 186 km/h...
You can check it out on the end of this page, the table of the transmission and gear ratios and the formula to get the real velocity :)
http://www.racingsm.org/motorkdx.htm
Hf guys ;)
I noticed on your spec page a reference to piston speed of 22 m/s, which is over 4,300 fpm. I thought around 4,000 was getting close to the upper end of the design envelope, so that's pushing it to say the least.
I don't imagine you get much connecting rod life, eh?
I don't imagine you get much connecting rod life, eh?
- Thread starter
- #10
23jayhawk, in fact the piston speed is 22m/s, it means the engine is on the maximum performance without puting in risk the reliability.
About the clutch, we used special strengthened springs, we were afraid that the clutch wouldn't hang on such power, but this Kawasaki engine surprised us very much :)
Like the 3 KIPS valves, mechanical centrifugal ones, are very useful for this kind of top-end racing engines, because they give a very good low/mid torque.
About the connecting rod life, i must say that it's new like when we bought it 1 year ago lol :)
The only bad things I noticed on this KDX 200 model, are:
- high stroke (58mm) that doesn't permit too much rotation, because of piston linear speed.
- The "T's" of the guide, had been transformed to assure the reduction of the height of the front side.
- The gears aren't good for a velocity preparation, because the diference between 5th and 6th gear is always about 29 km/h, and if a person wants to prolongate the final transmission too much, if he doesn't have a very powerfull and precise top-end engine mod's, maybe he couldn't put the 6th gear lol
The air filter doesn't exist because we want the maximum volume air-fuel to get the maximum horsepower with 13,5:1 compression ratio with 98 octane gasoline. (the same process in the 2-stroke GP bikes)
About the clutch, we used special strengthened springs, we were afraid that the clutch wouldn't hang on such power, but this Kawasaki engine surprised us very much :)
Like the 3 KIPS valves, mechanical centrifugal ones, are very useful for this kind of top-end racing engines, because they give a very good low/mid torque.
About the connecting rod life, i must say that it's new like when we bought it 1 year ago lol :)
The only bad things I noticed on this KDX 200 model, are:
- high stroke (58mm) that doesn't permit too much rotation, because of piston linear speed.
- The "T's" of the guide, had been transformed to assure the reduction of the height of the front side.
- The gears aren't good for a velocity preparation, because the diference between 5th and 6th gear is always about 29 km/h, and if a person wants to prolongate the final transmission too much, if he doesn't have a very powerfull and precise top-end engine mod's, maybe he couldn't put the 6th gear lol
The air filter doesn't exist because we want the maximum volume air-fuel to get the maximum horsepower with 13,5:1 compression ratio with 98 octane gasoline. (the same process in the 2-stroke GP bikes)
jaguar
~SPONSOR~
Hi. questions:
Why use a steel cylinder liner instead of nikasil when everyone agrees that nikasil is better because it poses less friction and lasts forever (if not scratched)?
What is the ignition timing? What is the PMS in "PMS of the piston" stand for?
What was the squish band reduced to? (what measurement)
In exchange for some tuning advice I can translate your page to english.
Let me know. thanks
Why use a steel cylinder liner instead of nikasil when everyone agrees that nikasil is better because it poses less friction and lasts forever (if not scratched)?
What is the ignition timing? What is the PMS in "PMS of the piston" stand for?
What was the squish band reduced to? (what measurement)
In exchange for some tuning advice I can translate your page to english.
Let me know. thanks
Canadian Dave
Super Power AssClown
- Apr 28, 1999
- 1,202
- 0
Impressive stuff BroLy thanks :)
David
David
jaguar
~SPONSOR~
Here's the basic spec differences between stock and modified:
Std / Modified
--- ---------
120 / 136 *** degrees of intake port opening (some ports raised 4mm)
194 / 198 *** degrees of exhaust port opening
7.7 / 13.5 *** compression ratio at high rpm's
35 / 41 *** carb diameter in mm
yes / no *** air filter
std / lighter *** flywheel
std / modified *** exhaust pipe
36 / 52 ***horsepower (44% increase!)
19 / ? *** ignition timing BTDC
7500 / 9400 *** rpm at peak hp
9,500 / 11,400 *** max rpm
135 / 187 *** max speed in Km/hr
piston: std sized Wiseco
reed valves: 4 petal carbon fiber (which open/close faster due to lighter weight than fiberglass)
spark plug: NGK B10 EG
KIPS actuator was modified to actuate the valves 2500 rpm earlier (at 3500)
Carb is Mikuni TM 41mm w/o power jet
stronger clutch springs
motor oil: Motorex GP synthetic
Longer connecting rod (from KTM 200) to insrease the rod angle at half stroke from 74.5 to 76 degrees. (for less stress on piston walls and more direct downward force on the crank and less lateral force)
Iron cylinder sleeve used instead of original nikasil
Std / Modified
--- ---------
120 / 136 *** degrees of intake port opening (some ports raised 4mm)
194 / 198 *** degrees of exhaust port opening
7.7 / 13.5 *** compression ratio at high rpm's
35 / 41 *** carb diameter in mm
yes / no *** air filter
std / lighter *** flywheel
std / modified *** exhaust pipe
36 / 52 ***horsepower (44% increase!)
19 / ? *** ignition timing BTDC
7500 / 9400 *** rpm at peak hp
9,500 / 11,400 *** max rpm
135 / 187 *** max speed in Km/hr
piston: std sized Wiseco
reed valves: 4 petal carbon fiber (which open/close faster due to lighter weight than fiberglass)
spark plug: NGK B10 EG
KIPS actuator was modified to actuate the valves 2500 rpm earlier (at 3500)
Carb is Mikuni TM 41mm w/o power jet
stronger clutch springs
motor oil: Motorex GP synthetic
Longer connecting rod (from KTM 200) to insrease the rod angle at half stroke from 74.5 to 76 degrees. (for less stress on piston walls and more direct downward force on the crank and less lateral force)
Iron cylinder sleeve used instead of original nikasil
Last edited:
