Thought i would see what you guys think about this. Got my new Boysen carbon fiber super stock reeds put in and the Fmf power core two silencer and fatty pipe on , re-jet carb to 270 and the bore on the motor is .020 the air box lid is on. I did not do a plug chop yet but 2 1/4 turn out on the air screw is where it want's to run. If i turn it more to the standard 1 1/2 turns it will bog out or won't rev up like it hits a rev limiter. Is this a problem or what do you think if you guys think it is a problem i could toss the 260 main in and go at it again.
Air screw 2 1/4 turns
- Thread starter 94 Blaster
- Start date
the main wouldn't be affecting the air screw adjustment, sounds like you need to change the pilot jet
Blaner
Your Friendly South African Ambassador
just clean it up and stick it back. main jet has no effect on idle. the pilot jet and screw does that.
You don't need new, they don't wear out
Just make sure you can see through the holes, check the ones on the side, they are real small. I:IIm in a similar spot. 2001 Blaster, FMF fatty pipe , Powercore 2 ,Boyesen Rad Valve, and port n polish cylinder,k&n,box lid delete,oil injection block off W/ premix. I got the Vito's Jet kit that comes with the new needle,30 pilot jet,290 through 340 main jet. Now in the instructions that comes with the rad valve, it states that you will need to go down in jet size between 1 and 3 steps. Now everthing else requires a bigger jet. I got the stock 32.5 pilot in , the 320 main jet, and the 4th clip on the needle. idle to 1/4 and WOT its a beast but the middle of the power band is a little flat. I've since tried all the different settings on the needle thinking that, I should start there being as its not the idle and not the top end. Same thing tho, It pulls best right around 2 1/4 turns out on the air/fuel screw....plug chop looks good, running 32:1 on the premix....Thoughts?
what ????
the boysen rad valve instructs to go down in main jet size ???
is this a fuel economy part, LOL
It says it does not increase air volume, only air velocity and redirects intake charge for a smoother flow and "you should expect to go between 1 and 3 steps leaner on your jet selection" looking at the part it looks pretty straight forward....cast housing, larger carbon fiber reed valves and carb boot...
Did I see above "tune the main, then work down to the needle and pilot, as the main has a trickle
Down effect "
If that's what I read (on my phone)
That's completely backwards and wrong. Period.
You must start with the float height, then pilot, needle and lastly the main, as all circuts in use effect the jetting range above it, not below it
Down effect "
If that's what I read (on my phone)
That's completely backwards and wrong. Period.
You must start with the float height, then pilot, needle and lastly the main, as all circuts in use effect the jetting range above it, not below it
Well, if that's wrong, we need to clean up all the "bad" info on this site!
As I have been jetting incorrectly this whole time.
I will delete my post definetly do not want to give bad info!!
I came a cross this on Keihin site , I can't say if this will work for mikuni's or not! Couldn't really get an manufacturer info from mikuni!
http://www.keihin-us.com/am/_media/pdf/slide_valve.pdf
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It's all about transient fueling when changing between circuits. What is important is what state you are in when you make the transition. Lets say you are rich on the main. When you transition into the needle, being rich prior will affect how you set up the needle. Same goes on the opposite transition. If you are lean on the needle this will affect the main and you will need to go richer to make up for the lean situation you had on the jet. All transients affect each adjacent circuit coming into or off it.
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Something a little easier, and more consistent would be to use the throttle limiting screw in the stock throttle housing. This way you know you're getting to the same throttle position each time
BTW, on my phone i do not look at who posted, only whats written
http://www.keihin-us.com/am/_media/pdf/slide_valve.pdf
/\/\ that link shows
#1 - setting floats,
#2 - getting it to idle with airscrew adjustments
#3 - adjusting the pilot according to the airscrew settings
#4 - adjusting the needle
#5 - main jet
i think they're numbered in that order for a reason
this is the jetting guide i have used on here since day 1,
same sequence as above...........
http://www.blasterforum.com/do-yourself-20/jetting-101-everything-explained-1625/
why have you kept that lil tidbit a secret for so long
it's brilliantly simple !!!!!
http://www.keihin-us.com/am/_media/pdf/slide_valve.pdf
/\/\ that link shows
#1 - setting floats,
#2 - getting it to idle with airscrew adjustments
#3 - adjusting the pilot according to the airscrew settings
#4 - adjusting the needle
#5 - main jet
i think they're numbered in that order for a reason
this is the jetting guide i have used on here since day 1,
same sequence as above...........
http://www.blasterforum.com/do-yourself-20/jetting-101-everything-explained-1625/
why have you kept that lil tidbit a secret for so long
it's brilliantly simple !!!!!
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It's all good and glad you caught that!
I just copied and pasterd what i had in my subscription threads-(Not anymore!!) No need to be giving out wrong info!
I will be also using this way from now on, and recommending it to all keihin users!
I just copied and pasterd what i had in my subscription threads-(Not anymore!!) No need to be giving out wrong info!
I will be also using this way from now on, and recommending it to all keihin users!
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