KR-1S.co.uk Forum

Those are the plugs I would recommend and what I use in my race bike.

I can't comment on the temperature gauge, I got rid of mine ages ago, as they are useless IMO.

I use a Scitsu gauge for accuracy and it comes with it's own temp sender which screws into the head in place of the original sensor.

http://www.ebay.co.uk/itm/Scitsu-Temper ... 3cc998463d

blimey, that's a bargain for the price. I'd have thought they'd be £100+. For less than the price of std sender from dealer! I'd be tempted at that price!

Shock, rebuilt by Rev's. £145, including making a new piston shaft

That looks just like a KR-1S shock except mine if memory serves me right, had a rebound adjster on the lower part, which that doesn't seem to have.

Any ideas anyone?

Hi Phil,
Yep the Original B1 and B2 had problems with the ring pegs falling out regardless of mileage so that wiould be a design fault.
Later pistons that superseded these were better,but they still suffer from a problem with the ring pegs coming loose,normally its down to high mileage,hard use from cold so the rings start "pumping" against the peg as the ring moves in and out of the ports or using poor quality oil.
Thats why i say,change them at around 3000 (road miles) and run decent oil and warm it up before opening it up then you should be fine.
Even if you bought a bike thats had recent pistons,unless you know the guy is mechanically sympethetic then change them,gives you peace of mind and a clean slate to start with.
Even the mitaka pistons have the same probs as the OE ones.
For some reason they are 1KT/DT 125ypvs pistons that are sold for the KR,nothing wrong with that but they have a slightly lower distance from the wrist pin to the piston crown,lowering the compression and opening the squish band up(mine went from 0.7mm to 1.00mm),i doint know if they are all like that or wether i was just sold a dodgy batch.
If they are then its a case of make your own thinner base gaskets up to close the squish up (0.7mm is as close as i would go on unleaded).
plugs,yep ther ones you have mmentioned work well,but think about what Luders said,he uses them in his RACE bike,if there colder enough to remove heat in an engine that spends ALL its time between 8 and 11,000rpm then there TOO cold for road use.
I really dont know why the S came with 10,s as stock,i think it was just a way of Kawasaki covering themselves after building the Fastest 250,maybe thinking everyone would be out there trying to crack 135mph down the local by pass.
Like ive said i always use 9's for road use and 10's on the track whatever the bike whatever the tune,and when i used to ride on the road it was usually with enthusiasm
Let us know how it goes,shock looks good by the way.
ATB
Dave

Luders- adjuster is on the other side!

dave32- thanks for the info. Where's the best place to go for pistons? And what do you make the base gaskets out of?

I really like the idea of that Scitsu gauge Luders

philfingers wrote:Luders- adjuster is on the other side!

dave32- thanks for the info. Where's the best place to go for pistons? And what do you make the base gaskets out of?

I really like the idea of that Scitsu gauge Luders

lol, I was wondering if it was hiding on the other side. It's been a while since I've actually seen a KR-1S shock.

You can buy gasket paper to do your base gaskets, but if you do go for mitaka pistons, just double check the dimensions and squish, as they may have changed, but doubt it.

I usually get my stuff from James at BDK, mainly as I'm usually having something else done at the same time, but there are loads of suppliers of after market pistons.
Wossner also make pistons for the KR, but they will be more expensive that the Mitaka ones, just depends what you're after.

The KR starts loosing power as the engine gets up past the mid 60's in temperature.

On a hot day, keeping the engine cool is a nightmare. I think I've found a solution that doesn't involve an expensive custom rad, but I'm yet to test it, so I am not posting any details at the moment.

The Scitsu gauge tells you exactly the temperature in 2 degree increments, so I can see when it's fully warm before I thrash it and see when it's getting too hot.

I've had issues with a base gasket once in one race and the scitsu saved my engine. Basically I saw the temp go up rapidly and I just pulled off the track. If I hadn't had the temp gauge, the engine would have likely siezed, as I wouldn't have spotted the problem as fast with the standard gauge.

Hi Phil,
Yep you can get gasket material off ebay
http://www.ebay.co.uk/itm/THE-ULTIMATE- ... 35bc0481e4
I used this company recently to make gaskets for my RG5 and KR1,really good service,and next time you need a gasket you can just make your own.
Must admit every KR ive known has always ran in the lower 3rd of the stock gauge even when ridden through town on a hot day.
You can run a scitsu,its what i use on my TZ,there fairly cheap and well made,but the you will probably run into the hassle of having to mod the rad to take the sensor as there a capillary type not electric.
Pistons,i dug out some old Mitaka pistons to see if they have changed (they used to be made in Japan,now its taiwan),and NO the others measure up the same ,i.e shorter,i always wondered why the box had 1KT/dt125ypvs crossed out,just asssumed they were using up old boxes.
So does anyone know if Mitaka specifically made a KR piston?
Ive used a few suppliers for these (grampian,pj engineering) so im guessing not.
Are you building this bike for road or track? as there is a big difference in whats needed/matters .
ATB
DAve

Dave, just road use. But I want the bike to be right to use, it’s a collectible thing as I see it so I want it largely standard but it’s not going to be wrapped up in cotton wool, it will get used!
viewtopic.php?t=8261
good thread there on the differences between Mitake and Vertex pistons. Pity there are no up dates, as maybe tempted by the Vertex DT125 ones.
I’m sure the Scitsu gauge would fit in the std place, it’s a std thread, is there back light in them, or provision for one? About the only time I find the time to ride the bugger is in the dark!

The threads are slightly different, so you will need to tap the thread. I have the tap in my toolbox, I'll have a look when I get home and tell you the size.

There is no back light on them and not sure if you could retro fit one, but in my experience, pretty much anything is possible with a bit of ingenuity.

I can send you an old gauge if you want to look for yourself.

I was guessing they were threaded into a boss on the rad like the TZ but if there not then fair enough.
TBH though there is nothing wrong with the stock setup for road use,you are riding in constantly varying conditions and speeds unlike on the track where once up to temp it should stay there providing its not jetted too lean/rich.
So if it goes above 60 degrees it really is not going to matter and you cant do anything about it anyway.
Im not sure the powefade above 60 is really true,reason being both the h***a RS and Yamaha TZ manuals recommend 70 degrees as running temp,i was told by Dennis TRollope to keep the TZ at 60 someone else who runs one at high level said 50,my take on it is if you stick to one temp 50/60/70 and set the jetting for that then you will be fine,if you jetted for 50 and it goes up to 70 then you will have problems.

Yep i understand you want to do it right and it will be used not just parked up and polished,thats why i said road and race prep and use are night and day,they need to be,here's an example of some of the small adjustements i make between the 2 on the same engine.

Road
B9EGV
150 main jet
needle on 3rd
Airscrew 1 1/2 out
pre mix 40.1

Track
B10EGV
155 Mainjet
Needle on 4th
airscrew 1 turn out
pre mix at 30.1
These are base settings,i will change the main if the weather calls for it.
If i used this setting on the road it would run way too rich and maybe foul a plug,conversely the road settings would run too weak leading to powerfade through overheating and eventually a seized piston.
One spends all its life above 8000 the other has to put up with idling at traffic lights,getting stuck behind traffic,sitting at a constant 5000rpm on the motorway and high speed blasts,lottsa variation unlike the track in otherwords.
There isnt a magic setting that will suit everyone,one of the reasons its a bad idea to copy someone elses jetting,different riding styles call for different settings even on2 identical engines,this is just an example of what i use.
ATB

thanks Dave. I'm on stock settings, but i have dropped the needle one click to make it a bit leaner. I read somewhere on the forum that it was the things to do as stock they were a bit rich. I'm sure thats' what I did, so it's on the 3rd groove usually, now it's on the 2nd from top, so effectively leaner
May get a ticker with it tonight. Shock needs another 10mm of preload I reckon

Hey phil,
Erm,ive never heard that one before about stock needle setting being too rich,in my oppinion there's way too many variables for a statement like that to be "set in stone" fact.
Take this example,
one guy lives at sea level and spends his time on the KR just going for A road blasts,if he goes through a town/slow built up area its not for long and he doesnt care if it needs "clearing out" after he gets back up to speed.Stock settings are fine in the summer months(less oxygen) but come autumn when the temp drops he's borderline lean.
The other guy lives at fairly high altitude,and spends his time just bumbling along with the occasional foray into the powerband.(stock settings are far from ideal,he could get away with a smaller main and hotter plug).
As far as im aware,maunfactures do jet there bikes for sea level(more oxygen needs richer fuel/air setting) and tend to play it safe by being slightly on the rich side of ideal as they have no way of knowing where or how it will be used.
Also the oil will have an effect on combustion,some burn cleaner than others,some have octane stabilisers (adding oil reduces the fuel octane),some have lots of detergents to keep powervalves and combustion chamber carbon build up down to a minimum,really these are more aimed at low power low maintanance engines not something like the KR that puts out over 200hp/litre as standard,with these load bearing is more important and no adverse effects on combustion(pro 2/motul 800 belrayH1R and Putoline RS959 work well).
So take all the variables into account and you can see there is no right or wrong jetting,you've got to find what works best for your needs.
The golden rule is always start too rich and work down,start too lean and you wont know it til its too late
You dont need a dyno to accomplish this just a bit of patience and a feel for what a rich or lean mixture feels like.
In basic terms,overrich will make the engine cough and splutter before maybe clearing its self out,sometimes in the lower gears it wont you need to be in a higher gear so it gradually clears,also it wont rev out as far and will have crackly exhaust note,revs will also drop quickly and it probably wont idle.
Too lean,when the engine is run up on the stand it will probably feel very lively and snappy off the throttle,before its up to temp,when its put under load it will feel gutless,the exhaust note will be quieter and the more throttle you give it the worse it is,rolling off may make the bike accelerate,as the temp of the engine rises this gets worse,also the revs take a long time to drop after the throttle is shut off.
Bear in mind ALL settings overlap somewhat,there is no cut-off point from one to another so an too rich needle settings will effect the main and so on.
Plug chops are fine to an extent,but all there doing is showing you if the main jet is right,you could still seize an engine if the needle was set too lean,this wouldnt show up,what would happen is after a high speed blast you roll off then it seizes.
My advice,put the needle clip back,ride it around a bit if it seems to show signs of being rich THEN drop the needle(raise the clip),might save a few tears at bedtime
ATB

I take on board what you're saying. I have ridden it already about 100/150 miles and it feels rich, hence the reason to drop it a clip. I read a number of threads re the mixture screw and I think I settled for 1 1/4 turns out but maybe wrong. I should write it down! The carb settings were bone stock and it was unmessed with too.
I'd have pulled it apart tonight when I did the preload change only I'm away with the greybike forum tomorrow eve (Friskney, nr Skegness. Pub, band & beer if anyone wants to come) and only realised last night the NC was out of MOT 3 months ago! Only done 200-300 miles on it, so no ticket through the mail yet, so it's in need of an MOT tomorrow. So can and number plate change over
KR runs on Pro2, or what's left of a bottle I had, I run my chainsaw on it, good oil, cheap insurance! However I got 10ltrs of the Full Syn Race oil from Hein Gericke in the Jubilee sale so it will run on that once the Pro 2 is gone
Whats the difference between the B9 EGV and the BR9 EIX plugs. They're a similar price? My rubber plug caps came today too

Hi Phil,
yep well if it feels rich then by all means try dropping the needle clip,sometimes 1 position is too much though and you need something inbetween,if this is the case you need some small shims to sit under the clip.
Not much difference in performance between the IX and EGV,take you pick.
jUst something to think about,you may find the reason for the "rich" feel is the plugs being too cold,when you fit 9's it maybe fine on this setting.
Another thing you may want to do is drop the front sprocket down to a 14T,this gives much more zap in the higher gears,standard gearing is way too high in most situation IMO.
I have tried 13/41 and that will still pull 120mph,goes up the box like a MX
ATB