KR-1S.co.uk Forum

Heres a sneak peek of what I will be doing in the near future with the bike:







New carbs have TPS and electronic powerjets, carb is a PWK36 which is basically an underbored PWK 38.

Will mean me making new carb intake rubbers so will use generic mikuni 38mm inlet stubs bolted to a plate.

Will be running separate coils to each cylinder and 2 pick ups with one lobe on the flywheel.

Maccas

They look tasty ! - will be very interested to see how you get on with the electronic powerjets

would it be possible or even advantageous, to replace the existing rotor and stator coils with something from (for exampe) a KX250 and add an extra pickup 180Degrees apart?

scooble wrote:would it be possible or even advantageous, to replace the existing rotor and stator coils with something from (for exampe) a KX250 and add an extra pickup 180Degrees apart?

It would indeed.

Hi Scooble,

I plan to fit another pick up 180 degrees around from the original pick up and grind one of the lobes off the standard KR flywheel.

I am sure it could be done another way using the flywheel/stator from another bike but I think it will be much easier to use the original flywheel/stator and simply add another pick up.

I will then be able to get both cylinders running exactly the same real advance negating the effect of crank twist due to the primary drive being driven off the right hand end of the crankshaft. The crank twist effect usually causes the right hand cylinder to run more advance than the left hand cylinder with the standard set up.

Maccas

By gum what lovely weather we are having!

Fitted the new ignition the other day, still running the pwk35's for now but i've altered the jetting a bit.

Just using one channel on the zeel for now but when i get round to it i will run 2 coils, 2 pick ups and one lobe on the flywheel.

Carb settings:
162 mains
DEL needle clip number 4 from top
48 pilot
Pilot air screw 3 turns out
Slide number 6.

I am rich from 0 throttle to about 1/4 so will try 45 pilot and wind the air screw back in a bit as i think its beyond its useful range at 3 turns out.

Did the front fork seals yesterday and its a different bike now, suspension is so much better. The old oil was so black and horrible lol.

Did 120 miles on it yesterday and its ace! Goes like stink from 8k to 10.5k then slows down after that, revs to 11k which is fine by me.

Mains will be too rich but the upper midrange is mint now so leaving it as is.

Love it, the sound when the kips open is something else. Proper chuffed with how its turned out.

Hopefully taking it to cadwell at the end of the month.

Maccas

maccas wrote: Proper chuffed with how its turned out.

You should be maccas, it's a good looking bike you've put a lot of effort into it, and it sounds like it goes as good as it looks.

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did you ever refit the reed stuffers...
just wondering if that might contribute to your rev range - inlets tend to reduce in section (nozzle) on the way in and expand on the way out.
...your unstuffed reed cage might be a dramatic change in area that could somewhow create a disruptive wave on the carb side

however, on the exhaust side (H0NDA RSxxx) it has been proven detrimental to match the pipe diameter to the exhaust flange - whereas a step here is beneficial (against what might be assumed to flow better)
... my analogy here is you need a pair of lips (aperture) to blow a trumpet - the wave is generated at the mouth piece - would connecting a trumpet to an air supply (without a mouthpiece) make the same tones.

Did you alter your squish and/or compression? (that can narrow the revability)

Pablo,

Cheers mate

Danny,

No i haven't fitted them yet, i'm going to buy a set of v force reeds soon so didn't bother but yeah i'm sure there would be an improvement.

The head has been worked at some point in the past, squish is 1mm with a volume of about 11cc if i remember correctly

Maccas

What do other peoples bikes rev to on the tacho?

Maccas

About 12k - there is a video somewhere of the KR at Anglesey - you can see what it goes to there.

I run main jets between 152 and 158 depending on the weather. If you are on 162 I suspect you might be a tadge rich which will limit overrev. There again that will be safe for the road. A stock KR-1R is meant to run 145 which is way to small?

Your bike isn't far off the spec of mine. I did find that raising the KIPS and main port 1mm brought the Lomas pipes on song. On stock porting they loose a bit right at the top but still give the mid range. Raising the exhaust didn't loose any midrange and added some at the top - allows it to rev out.

Mine will only go as far as 11k before power drops right off.

Couldn't tell you what my lump is because it came out of Matty's race bike, I couldn't even tell you whats in its carbs.

As soon as I break it, I will let you know

Actually I haven't been of much help there really maccas have I, sorry

Danny,

I haven't touched the exhaust duct but from when i fitted the lomas pipes i think that the exhaust flange hole is the same diameter as the exhaust duct so i won't have a step. That is something i will look into. Cheers for the pm with the link to the reeds

Mj,

My barrels are kr1 with a stage 3 tune of some sort bit this tune was done a long long time ago as the bike hadnt been taxed since 99. The main exhaust looks to have been raised slightly and so do the transfers but not by alot. The kips are still quite small so i think it might be this which is holding the revs back. There is a big mismatch between the kips duct and the powervalve on the cylinder side where i didn't have a decent enough tool to match the kr1 kips tunnels into the kr1s valves.

Jetting wise with 155 mains i was still jetted safe as i plug chopped and it revved on till 11250 but the midrange is much fatter now with 162's and i've only lost 250 revs.

This is where the electronic powerjets on the new carbs will come in allowing me to keep the fat midrange and gain some overrev by leaning off the jetting after peak.

I have some 1s barrels that have been strengthened by bdk at the back and they look to have had some porting done too, after a replate they will be going on.

Howie,

Do you know if you are running 1 barrels and pipes and ignition?

Maccas

Hi maccas,

Not sure about my barrels, I'll have to whip one of the resonator covers off & have a peek.

Definately 1s pipes & kr1 ignition.

Taking the bike to james at krazy-katt mid april to set it up on the dyno. Watch this space.

Dan (maccas)