'fingers KR1-S C2 tinkering with a mostly stock bike
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- Heavy Smoker
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Between 1 and 1/2 out works ok for most,just a case of giving it a go and seeing if its better,bit of a bugger you cant get at both airscrews easily though.
Here's another thought for ya,
SAy you had a mainjet that was too rich,when you shut off and want to just provide a small amount of drive so your back on the pilot/airscrew and maybe slide cutout,if this feels too rich (tends to be a delay in response) it could be the main not the others.
Reason being is youve supplied to much fuel withy the main,when you go back on part throttle(the hardest part of combustion) the fuels still there.
HTH
Here's another thought for ya,
SAy you had a mainjet that was too rich,when you shut off and want to just provide a small amount of drive so your back on the pilot/airscrew and maybe slide cutout,if this feels too rich (tends to be a delay in response) it could be the main not the others.
Reason being is youve supplied to much fuel withy the main,when you go back on part throttle(the hardest part of combustion) the fuels still there.
HTH
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- Heavy Smoker
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re PM, no worries, thought I'd ask!
I'm probably going to have it run up on the dyno, will give me a better idea of exactly how it is, had the NC30 and the YB on there last w/e end.
The NC was on the rich side, with stock settings, other than an ART can. YB was nice all the way through, good carburation, stock thunderace motor with Two Brothers can
Lambda sensor had gone tits up on the YB run, hence the AFR
http://www.youtube.com/watch?v=TUUrj-D5 ... e=youtu.be
I'm probably going to have it run up on the dyno, will give me a better idea of exactly how it is, had the NC30 and the YB on there last w/e end.
The NC was on the rich side, with stock settings, other than an ART can. YB was nice all the way through, good carburation, stock thunderace motor with Two Brothers can
Lambda sensor had gone tits up on the YB run, hence the AFR
http://www.youtube.com/watch?v=TUUrj-D5 ... e=youtu.be
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- Heavy Smoker
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- Joined: Sun Oct 24, 2010 10:15 pm
I dont know,i mean it will show you the HP but it wont show you if the jettings right all the way through the range.
I think EGT sensors are the way to go for a racebike,Air fuel readings sometimes need to be richer than the theoretical ideal on 2strokes to give good power.
Also we live in a country where the weather can change quickly so if you jet for max power reading on the dyno,it might be too weak on a colder day.
Personally its far better to just ride it as you do and try making adjustments,lets face it wacking the throttle to the stop at 6000rpm on the dyno is not the same as how you ride it.
I think EGT sensors are the way to go for a racebike,Air fuel readings sometimes need to be richer than the theoretical ideal on 2strokes to give good power.
Also we live in a country where the weather can change quickly so if you jet for max power reading on the dyno,it might be too weak on a colder day.
Personally its far better to just ride it as you do and try making adjustments,lets face it wacking the throttle to the stop at 6000rpm on the dyno is not the same as how you ride it.
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- Heavy Smoker
- Posts: 207
- Joined: Tue Apr 12, 2011 11:14 am
- Location: Worcestershire
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- Heavy Smoker
- Posts: 207
- Joined: Tue Apr 12, 2011 11:14 am
- Location: Worcestershire
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- Heavy Smoker
- Posts: 207
- Joined: Tue Apr 12, 2011 11:14 am
- Location: Worcestershire
doh, again!
Would 10mm preload on and it's way too much, needs 5mm I reckon.
Also the air filter is goosed. falling apart. Suggestions for a new one?
is this sufficient? http://www.ebay.co.uk/itm/New-Air-Filte ... 2eb9f8d7ad
Would 10mm preload on and it's way too much, needs 5mm I reckon.
Also the air filter is goosed. falling apart. Suggestions for a new one?
is this sufficient? http://www.ebay.co.uk/itm/New-Air-Filte ... 2eb9f8d7ad
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- Heavy Smoker
- Posts: 207
- Joined: Tue Apr 12, 2011 11:14 am
- Location: Worcestershire
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- Heavy Smoker
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- Joined: Sun Oct 24, 2010 10:15 pm
How come your using a different spring?
stock spring works fine if your between 8 and 12 stone.
Do you still have the stock spring to try?
You want around 5 to 10mm static sag for the road (0mm on track),and between 25 to 35mm sag when your sitting on the bike.
Compression damping wont effect spring preload and vice versa.
stock spring works fine if your between 8 and 12 stone.
Do you still have the stock spring to try?
You want around 5 to 10mm static sag for the road (0mm on track),and between 25 to 35mm sag when your sitting on the bike.
Compression damping wont effect spring preload and vice versa.
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- Heavy Smoker
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Sorry for the delay.
Well I knocked the preload off by 6mm so I'm at 158mm spring length. Feels fine. So I tried Dave's suggestion of 1.5turns out on the air screw and the thing was idling about 3k! non the less rode it down the road (couldn't mess around with tickover screw, was nearly midnight!) and feels better on the road.
I fitted the new air filter last night and the B9 EGVs turned up today, so will fit them later if I get chance.
The bike felt better on the 1.5 turns out tho. Be interesting to see if the new plugs affect the driveability of the motor
oh and spring info came from here, viewtopic.php?t=120 my stock one was saggy and old. £24 has made a difference
Well I knocked the preload off by 6mm so I'm at 158mm spring length. Feels fine. So I tried Dave's suggestion of 1.5turns out on the air screw and the thing was idling about 3k! non the less rode it down the road (couldn't mess around with tickover screw, was nearly midnight!) and feels better on the road.
I fitted the new air filter last night and the B9 EGVs turned up today, so will fit them later if I get chance.
The bike felt better on the 1.5 turns out tho. Be interesting to see if the new plugs affect the driveability of the motor
oh and spring info came from here, viewtopic.php?t=120 my stock one was saggy and old. £24 has made a difference
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- Heavy Smoker
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No worries phil,
So how much sag have you got when your sat on the bike?thats whats important.
im a bit worried now,i cant recall what your airscrew was on before but im guessing it was in further (a richer setting)?
As if winding the screw out has raised the idle rpm by that much it indicates either>>
There is an airleak in the intake manifold/reedblock rubber area,hence the need for a really rich airscrew setting to bring the revs down or...
the idle screws ar adjusted too high and someone has got confused and set the aircrew really rich to get the revs down.
i would bet its more likely to be the latter,its rare for the rubbers to crack ALL the way through,they just split on the surface generally.
The proper way to set the idle is,
1.Remove airbox (i know its a bastard thing! ).
2.set the slack at the throttle housing end to around 5mm (give or take)
3.Wind both adjusters on the carb sides out so they are not having any effect on the slide.
4.Looking at the slides from the rear and holding the throttle move them very slightly,what your looking for is one slide opening BEFORE the other,adjust til they are exact and working in unison by moving the cable adjusters at the carb tops in or out (make sure you still have slack at the throttle end while doing this,if not adjust)
5.So your happy,everythings working in harmony and they both reach full throttle at the same time,grab yourself a cup of tea and/or a fag now and relax
6.Setting the idle speed is now on the agenda,you cant guess it,it needs setting while the engines running ,your aiming for around 1000 to 1200rpm,any higher and they bang into gear.
You can make a start by winding the idle stop screws in until they move the carb slides around 1mm or so,fit the tank etc and fire it up,run it up on choke when cold and it should idle high (1500 to 2000rpm) for a about 30secs or so,then it should start loading the plugs up (recognised by the revs starting to drop),knock the choke off and vary the revs between 3 to 4000rpm for a minute or so,give the throttle a couple of blips up to say 5000 rpm and let the revs drop,you should now have some heat in the engine and can set the idle.
7.with the right side panel off and maybe the leave the tank slightly loose you should be able to get your hand to the left carb idle screw,wind it in or out along with the right to get a similar amount of back pressure from the tailpipes and the desired RPM.
a low pressure at the tailpipe or a pipe that takes longer to get heat in is generally caused by that cylinder not working due to the slides being out of synch,get this right and it will make for a much smoother more responsive engine.
To recap,a rich low speed setting will sound like like the engines burbling,choking itself and the revs will gradually drop til it stalls.
A lean idle setting will sound very smooth,quiet and when you blip the throttle the revs drop very slowly,also it will get worse as the engine gets heat in it (it may feel fine when cold).
You may have to rcihen or lean the airsrew a bit from the standard setting but not much,if you end up needing more than 2 turns out or further in than 3/4 out something else is not right.
ON the plugs again,check the gap is 0.5mm,there sometimes set too wide.0.7mm is fine for the standard ES type plugs not for fine wire types.
Oh and if your feeling like a bit more fettling you can slot the ignition pick and set the air gap to 0.25mm,tends to help with response.
HTH
So how much sag have you got when your sat on the bike?thats whats important.
im a bit worried now,i cant recall what your airscrew was on before but im guessing it was in further (a richer setting)?
As if winding the screw out has raised the idle rpm by that much it indicates either>>
There is an airleak in the intake manifold/reedblock rubber area,hence the need for a really rich airscrew setting to bring the revs down or...
the idle screws ar adjusted too high and someone has got confused and set the aircrew really rich to get the revs down.
i would bet its more likely to be the latter,its rare for the rubbers to crack ALL the way through,they just split on the surface generally.
The proper way to set the idle is,
1.Remove airbox (i know its a bastard thing! ).
2.set the slack at the throttle housing end to around 5mm (give or take)
3.Wind both adjusters on the carb sides out so they are not having any effect on the slide.
4.Looking at the slides from the rear and holding the throttle move them very slightly,what your looking for is one slide opening BEFORE the other,adjust til they are exact and working in unison by moving the cable adjusters at the carb tops in or out (make sure you still have slack at the throttle end while doing this,if not adjust)
5.So your happy,everythings working in harmony and they both reach full throttle at the same time,grab yourself a cup of tea and/or a fag now and relax
6.Setting the idle speed is now on the agenda,you cant guess it,it needs setting while the engines running ,your aiming for around 1000 to 1200rpm,any higher and they bang into gear.
You can make a start by winding the idle stop screws in until they move the carb slides around 1mm or so,fit the tank etc and fire it up,run it up on choke when cold and it should idle high (1500 to 2000rpm) for a about 30secs or so,then it should start loading the plugs up (recognised by the revs starting to drop),knock the choke off and vary the revs between 3 to 4000rpm for a minute or so,give the throttle a couple of blips up to say 5000 rpm and let the revs drop,you should now have some heat in the engine and can set the idle.
7.with the right side panel off and maybe the leave the tank slightly loose you should be able to get your hand to the left carb idle screw,wind it in or out along with the right to get a similar amount of back pressure from the tailpipes and the desired RPM.
a low pressure at the tailpipe or a pipe that takes longer to get heat in is generally caused by that cylinder not working due to the slides being out of synch,get this right and it will make for a much smoother more responsive engine.
To recap,a rich low speed setting will sound like like the engines burbling,choking itself and the revs will gradually drop til it stalls.
A lean idle setting will sound very smooth,quiet and when you blip the throttle the revs drop very slowly,also it will get worse as the engine gets heat in it (it may feel fine when cold).
You may have to rcihen or lean the airsrew a bit from the standard setting but not much,if you end up needing more than 2 turns out or further in than 3/4 out something else is not right.
ON the plugs again,check the gap is 0.5mm,there sometimes set too wide.0.7mm is fine for the standard ES type plugs not for fine wire types.
Oh and if your feeling like a bit more fettling you can slot the ignition pick and set the air gap to 0.25mm,tends to help with response.
HTH