oh dear never mind carry on

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KR-1R
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Jetting spreadsheet

Post by KR-1R »

.
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spreadsheet
^^^ may not be relevant for 28's but you can experiment with it and see clip position alone affecting mainly 30% to 65% WOT region.

it does depend on the combination scenario ... but your 1 mainjet size difference combined with radical clip position could be as bad as 10% leaner at 100% WOT than stock settings.

the above spreadsheet also includes altitude variation for all things KEIHIN.
if you password crack it you can adjust the sizes of the graphs etc :wink:
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Post by JanBros »

Fred, don't (never) change 2 things at once. Setting up carb's begins with finding the right main, and for that you need to run it WOT. find a long straight, run WOT and there you can do plug-chops. I would do that with the needle in a more rich position.

once you have found the best main, start changing the needle to find the best throttle response at half throttle.
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Post by mj43 »

I get the main right then use the clip position to adjust pick up out of corners.
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Post by JanBros »

isn't that the same :?: :D
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Post by dave32 »

The clip position has more of an effect than changing the needle (for the next leanest/richest).
on the TZ we change the Needle Jet depending on conditions,the needle never gets altered (its left in the mid clip).
On my RS 125,the needle gets changed (say a 66 to a 65 if you want to richen it up),the needle only works properly in the 4th or 5th clip (on the RS keihin),go any leaner and it has an effect on other parts (all to do with the taper).
ive never come across a KR that would need a leaner needle position than 2nd down and that was a stock B2 that got ridden like a granny by its owner.
I really dont recommend doing any high gear WOT runs until you know its not running on the limit,better off doing some 3rd gear acceleration,checking its not too lean THEN try the higher gears if its safe.
At WOT in say 5th or 6th it wouldnt take more than a few secs of running to melt the piston if its on the weak side ( as you have found out
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Post by fred »

when i went up to 145 on same clip position 2nd from bottom it wouldnt pull or awt like having choke on,throughout satday i lowerd needle so i could run it in a bit and it pulls cleanly ,now its bedded in and ile start again getting main right and note any changes i make
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Post by fred »

on 150rd middle clip,loads better more power ,choke has effect up to 9 10 grand ,but not above ten ,sounds a bit like a machine gun but clears ,will ritchen needle and swap some unused jets for some 147.5 ,but will check plugs when out on a run tommoro,cheers everybody
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Post by dave32 »

Sometimes ive found you need a "between the clip " position,one is too rich the next is too lean,i will have look see what size the ones i have are but im pretty sure there off an RC car.
So 150 it revved out okay?
If so its pretty close.
Another way you know the main is too big is when on the down changes you blip the throttle and it doesnt respond (with the clutch depressed),it LAGS behind your wrist movement and has a deep exhaust note.
Is it spluttering after its been "Cleared out" and you open it up again or just after pottering round/warming up?
If it feels all zappy and crisp before a blast or on the paddock stand it will always be too lean on the needle when placed under load.
be careful Fred,the weeks not up yet :lol:(pistons on shelves)
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Post by 500bernie »

Hi Dave,
Did you mean to say that you put a small washer between the slide body and the clip, to give you an intermediate position?
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Post by dave32 »

Hi Bernie, :D
Yes thats correct,there shims,will have a measure up later today but i still cant remember what there off of (model car wise).
No worries :D
Fred i just re read your post and im a bit baffled (sorry :lol: ),
You have Good power with 150RD's but you going to go Leaner?
The ONLY way to be sure it is TOO rich is to keep increasing the main jet size until it exhibits poor perfomance,THEN work down.
ATB
Dave :D
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Post by fred »

i know what you mean ,ive done 156 miles on the 150rd jets and when warm only four strokes in 1st 2nd this is on power accelarating from standstill above 9 grand ,all higher gears and speeds,revs are sound on these jets ,on load its sound ,roll the throttle off and not powering and it fourstokes ,so i think main is good it revs out to 12 and above ,let me put the standard pilots in (i think ive got 42`s or 45`s in that probably shrouded other things not being right) ime not going to touch needle till ive done that .
one thing ive learned is when the dyno showed up a ignition problem (a corroded pin in the ignition switch block connector) i did`nt say right now thats fixed lets start the jetting testing again from the top ,now i know ,cutting a spark intermitently does feel completely different from running rich WOT ,but it did send a novice like me on the wrong track ,i realy appreciate everyones advise
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Post by fred »

runs fine throughout on standard 40 pilots now ,second from top clip( will try middle again tommoro now ive put pilots back to 40 ) have a goodone :D
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Post by fred »

got round to changing the clip back to middle and checked the plugs (ginger biscuit color and it felt a bit strangled) put a 152.5 in and did 15 miles and seemy to be a lot happier everywhere and not so much fourstroking of the power like with the 42 pilots ,so going back standard on the pilots has leaned things down overall slightly ,
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Post by dave32 »

I still run stock pilots with the modded airbox and no air filter so i doubt you need to change from them.
your probably find the too rich pilot was confusing things with (off closed throttle response and accelerating in the lower gears after idling.
One thing ive noticed even on a stock KR1 is that in 1st and 2nd after normal riding it will always splutter when it gets to around 9000rpm or so.
Not something that occurs on the track (say coming out of mallory hairpin),i think its just the nature of the beast. :D
Whenever ive tried leaning an engine off so it wont do this (airscrew/needle position) it runs too lean the rest of the time.
Also some oils load the plugs up more than others when on a closed throttle but they tend to be the ones that give best underload performace and NO powerfade.
If your running the Motul 800 Roadrace it doesnt like low rpm use,the Off road is better for this,all depends what you want and how you ride. :D
One other mod i made was to shave 1mm off the airslide entrance as i was experiencing poor throtte response on the downchange (when the mixture was spot on under load),but this isnt something i would recommend unless you have some spare slides and nothing else sorts it.
ATB
Dave :D
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Post by fred »

i dropped needle t 2nd from top and it is the motocross motul 800 that`s all they had, went to get some more and ther waiting on a delivery so 710 at the mo ,i knew when ben told me that his bikes on standard pilots that i knew i had something off ,shese a rate happy thing now and i have`nt changed t sprockets back from 14 44,me misses has got a job now so hopefully i will be able to afford a visit to poeton before the summers out
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