KR-1S.co.uk Forum

Well it looks like I've got some 35mm carb holders being made so I should be able to fit them soon, I'll have to pull my finger out and get the airbox made first but apart from that she's ready for the dyno.

great piccy there elf! just wondered what discs you have on there? look pretty trick. also what other mods has it undergone? looks like a nice example been used as its desingners intended! what class do you run it in? cheers mgtkr1

they're PFM front discs and a wavey RGV rear

As for the list of mods, Well here goes, She's not upto the spec of MJ's KR but she's getting there:

ZXR400H SP model front end with ohlins internals
Radial Front Brake master cylinder
Ohlins rear shock
Ohlins steering damper
Stan Stenphen SS400 tuned engine with V-force 3 reeds, flowed cases, rebuilt crank (all new seals and bearings), and head machined to run on pure Avgas, with premixed oil.
Ram Air system fitted
Rearsets 80mm further back and 40mm higher
RGV 17" rear wheel
Raised rear suspension (shorter linkages)
Braided hoses
KR1R type Close Ratio Gear Box
Race Loom running total loss
Large capacity Radiator with small overflow tank
wets and inters on wheels (zxr400 front and RGV rear)
Scuisi Water temperature gauge
Hugger
new "keyless" fuel cap
KR1R fuel Tap
Standard exhausts with TZ endcans

New for this season are:
Dymag 17" x 5" rear wheel
Advanced ignition
KR1R 35mm carbs (holders are being machined ATM)
New large capacity air box with the carbs mounted inside it. (Being made ATM)
Slightly different tune on the cylinders from last year.
Nikkon expansions, wrapped, with TZ endcans.

She's running in the F250/F400 class with Derby Phoenix and being held back by a crap pilot She's back on the dyno again next Friday (without the new carbs or airbox though) so I'll post a dyno sheet up here afterwards (providing she makes over 55bhp ).

fooookin ell! some serious spec thjere m8, are the 1r carbs still out there somewhere avalible. i was gonna ave a go at ss400 this year but it all come round bit to quick need to get race licence sorted as ive never racedf before but my mate/boss did well on an rgv in the late 90s and he has an rrsp at BDK atm, was gonna go with him but wimped out till next year till i get a bike 2gether that will give me a bit more of a chance, still be at the back tho as i will be shite at least till i know me way round. building me own motor with the help of the very helpful website mj43 put together as a starting point then will see what happens. also get handling sorted and plenty of tyres! are there any other carbs that may suit if the kr1r ones prove to be unobtainible? p.s giving myself another year will allow me to be a bit more organised as the decision came to sudden to start march.

You dont need to get to high a spec bike to be competative at the back. The lads at the front have years of experience and they'll thrash you requardless of how high spec your bike is. I'm an engineer by trade so I've enjoyed making and designing the parts as much as I have pottering around at the back of the pack . I designed the whole CR gearbox after getting the ratio's of MJ site. Then got it all machined and heat treated. As far as we know only MJ's and my bike have the full KR1R spec CR boxes in this country.

The 35 mm carbs are readily availble from anywhere. They are just PWK35 jetted to suit. The big problem is that the airbox and inlet rubbers are no longer available from Kwak. Hence the new mounts that I'm having the lads machine for me at work. Also I find it a PITA changing jetting and the incentive for the new airbox is that it'll be alot easier to do once the carbs are fitted inside it.
BTW the rules state that you must fit carbs that were availalbe on that model so for the KR its either the standard 28mm PWK's or the KR1R 35mm PWK. You can't fit anything else.

Just get out there and race the bike you'll love it

cheers for the advice there elf, deffo gonna ave a go next year will probably get a lot of fun out of seein how the bike goes as much as anything else! just wanna build a nice bike thats track based but also conforms to the rules so some 1r carbs will be on the list at some point. will also get some rubbers made eventually. wont go racing as a mega serious thing but just go along as an excuse to run the bike learn something along the way i suppose. the air box mod sounds a good idea as jetting is a chore like ya said. is your ignition a modded stock item or did you have one made? also are the heads Mj had/having been done in batches or one off? re c/r boxes stan stevens used to sell the 2nd / 3rd i think as the gap was a bit big for the ss400 spec motors im not sure of exact details can anyone confirm? this was back in the 90s. cheers mgtkr1

Go out and have some fun, thats what racing is alll about at this level.

My ignition is a modded stock item ATM. I have found a decent proggramable module but I haven't got it yet and we were just playing with the standard stuff and advancing the ignition and seeing what difference it makes to the power.

MJ heads are a one off set he's had madeand will be experimenting with this season.

A few people I have seen have a semi close ratio boxes with 5 and 6th I think changed (could be wrong). Anyway all the gears are now NLA from Kawk so you can't get them any more. I must ammit to liking the CR box alot better than the standard.

BTW. I have a fully programable ignition on route . The 35mm carbs are fitted and working. Will have a play at Cadwell this weekend to shake them down and make sure it all works. Also just finished doing a new set of rearsets as well.

My main sponsor for this year is having to reduce his support considable so it looks like I won't be doing that many races unless I can get something else sorted soon,