KR250A race bike

[James P]

I spotted this neat much-modified KR250A at the Barry Sheene Festival of Speed earlier today:


Has the swing arm been turned upside down? Wheels are possibly from a Suzuki (forgot to check).


I've no idea what bike the fairing and seat unit come from - anyone know?


Large radiator. Ignition appears to be total-loss battery type with (very) small rotor. Water pump also appears to be non-standard. I'm no expert on the KR250A - there are probably a lot of other non-standard parts!




Hole for kickstart shaft plugged. RGV carbs?

I didn't notice some of the features while I was taking the photographs - only when I looked at them in detail later. If I had noticed earlier, I could have asked the bloke who was pushing the bike around . I did look at the list of competitors for the event (which also listed the bikes), but couldn't find this bike among them.

Regards,
James

[JanBros]

fairing/seat-unit looks awfull imho

[StrokerBoy]

Large radiator.

Certainly is !

It's possible that the standard swingarm has been inverted and then plated, or it might be off something else, looks well modified anyway. The whole thing has had a lot of work done in fact. Nice to see the anti-dive still in place, though it might be disconnected.

Many thanks for posting those pics, I love to see stuff like that. =D>

[smeg]

The KR250 was at the Barry Scheene to be run in and setup,

Got the jetting done, it pulls clean through the gears and engine temp is good (didn't go bang), it will visit the Dyno sortly to check the ignition is setup correctly but so far so good.

ok, guys your pretty close.


the swing arm is a KR 250 put in upside down and plated, the supports for the swing arm where welded and re drilled to get the angle right.
The rims are off a Suzuki across, the carbs are RGV (L model) slightly modified to fit.
Being that the original water pump is driven off the end of the crank shaft it would cavitate at 12,000 rpm, the oil galleries that were no longer needed and were sealed and a machined tooth drive was fitted to the end of the crank shaft and a external water pump was fitted and is driven by a toothed belt.
The radiator was custom made in china, basically it is has 4 times the capacity of the standard radiator, the water flow has also been reversed.
The bike runs a total loss Ignitech ignition.
As far as the engine goes the sleeves for the main bearings in the cases were replaced so that the main bearings do not spin (we heat the cases with a heat gun when splitting the cases), the reed valves have been removed so the engine is rotary disk. The transfer ports have been cleaned up and ported (nothing to radical)
the engine has over length rods.
The fairing is from a h***a RS250 I have to add about 150mm extra glass so it would fit.
The anti dive on the forks has been disconnected and is manually adjusted.
The seat is a rs250 seat I have since removed the pads and will replace them with some ting more appropriate (first temp failed)

I have since added some more decals and will post a few more pics once I'm happy with it.

[Top-shaggy]

Wow Smeg... Only your second post in TEN years
You are the master sir lurkalot..

But if that's true..
what a second post and special KR, hats off to you and please share some more pictures
I for one would love to know more about your bike

[StrokerBoy]

Thanks smeg, your bike is ace. More pics and details please, there can't be another KR that's been so well modified anywhere. =D>

[TwoStroke Institute]

The KR250 was at the Barry Scheene to be run in and setup,

Got the jetting done, it pulls clean through the gears and engine temp is good (didn't go bang), it will visit the Dyno sortly to check the ignition is setup correctly but so far so good.

ok, guys your pretty close.


the swing arm is a KR 250 put in upside down and plated, the supports for the swing arm where welded and re drilled to get the angle right.
The rims are off a Suzuki across, the carbs are RGV (L model) slightly modified to fit.
Being that the original water pump is driven off the end of the crank shaft it would cavitate at 12,000 rpm, the oil galleries that were no longer needed and were sealed and a machined tooth drive was fitted to the end of the crank shaft and a external water pump was fitted and is driven by a toothed belt.
The radiator was custom made in china, basically it is has 4 times the capacity of the standard radiator, the water flow has also been reversed.
The bike runs a total loss Ignitech ignition.
As far as the engine goes the sleeves for the main bearings in the cases were replaced so that the main bearings do not spin (we heat the cases with a heat gun when splitting the cases), the reed valves have been removed so the engine is rotary disk. The transfer ports have been cleaned up and ported (nothing to radical)
the engine has over length rods.
The fairing is from a h***a RS250 I have to add about 150mm extra glass so it would fit.
The anti dive on the forks has been disconnected and is manually adjusted.
The seat is a rs250 seat I have since removed the pads and will replace them with some ting more appropriate (first temp failed)

I have since added some more decals and will post a few more pics once I'm happy with it.

I had a look and a listen to the bike at the Barry, I don't think the ignition or the carburation is right.Are you running an EGT probe? The pipes could also be an issue. It never sounded sharp. Was great to see it out there and someone doing something different.

[Gerrit]

A pretty neat conversion! I'd love to know more about the rear suspension setup- any pics available?

It's a shame that this model was never exported to Europe officially, KHI really missed the bus by not doing so.

[smeg]

More pics of the KR250 race bike project, but first in answer to this post

"I had a look and a listen to the bike at the Barry, I don't think the ignition or the carburation is right.Are you running an EGT probe? The pipes could also be an issue. It never sounded sharp. Was great to see it out there and someone doing something different."

The jetting is pretty close, I do not run a probe. The bike does not start to pull until 7,000 then starts to pull hard around 9,000 and it jetted a little rich down low so it will not sound crisp in the pits. As I said in a previously the bike needs to go for a Dyno session to setup the ignition curve and a tweak of the jetting.

One think i did not mention before is that the primary drives have been custom made so that they engage both sprockets on the clutch drive.

I have also fitted a steering damper.

[smeg]

More pics cooling system, the system is now self bleeding.

[smeg]

Pic for the ignition system, Coils are under the front tank mount. The battery and the ECU are forward of the folks and under the Tacho, runs a total loss system.

[smeg]

More ignition pics

[smeg]

Steering damper just added

[StrokerBoy]

=D>

[podman]

Lovely, what a cracking piece of Kawasaki history kept up to date for the job in hand with some subtle mods..fair play Sir.