jetting help

[La 450 smoka]

Well i've been searching this site for jetting tips and I've got her spot on from bottom to 3/4 throttle.If I try to accelerate from down low in the rpm's and I use anywhere from 1/8 to 3/4 throttle,it is very responsiveand it accelerates briskly and smoothly.(I changed from 3rd to 4th needle clip position ond went from 1 3/4 on air screw to 1 1/4 after reading hints from this site,and it helped big time!)Well there is still a problem lurking about.When I mash the throttle anytime when I'm not on the pipe,it falls flat on its face and will barely accelerate and kinda cuts out,but accelerates good when it gets on the pipe .I am currently running pro circuit plats with dual k&n's.Not sure about pilots,but 310 main jets and a dune port job.It sounds to me like it is lean If so,Ive got sum 340's,would they be worth a tryat 0 elevation(sw Louisiana)(?)Anyone out there that can figure this one out?By the way,what's that jet for inside the bowl parallel with the main?(under that little plastic shield)

Edited September 4, 2005 by La 450 smoka

[Handyman]

Well i've been searching this site for jetting tips and I've got her spot on from bottom to 3/4 throttle.If I try to accelerate from down low in the rpm's and I use anywhere from 1/8 to 3/4 throttle,it is very responsiveand it accelerates briskly and smoothly.(I changed from 3rd to 4th needle clip position ond went from 1 3/4 on air screw to 1 1/4 after reading hints from this site,and it helped big time!)Well there is still a problem lurking about.When I mash the throttle anytime when I'm not on the pipe,it falls flat on its face and will barely accelerate and kinda cuts out,but accelerates good when it gets on the pipe .I am currently running pro circuit plats with dual k&n's.Not sure about pilots,but 310 main jets and a dune port job.It sounds to me like it is lean If so,Ive got sum 340's,would they be worth a tryat 0 elevation(sw Louisiana)(?)Anyone out there that can figure this one out?By the way,what's that jet for inside the bowl parallel with the main?(under that little plastic shield)

411462[/snapback]

 

Sounds like a carberation problem. The jet that is parallel with the main jet is the pilot jet. I believe 340 mains will be too rich for a 0 elevation but then again with your port job that may be needed. I am running the same set up as you as far as exaust system and K&N filter pods but my jetting is a 290 main and stock needle in the 4th clip position from top and I'm at about 400ft above sea level. My air screws are turned 2 full turns from seated. I had some what the same problem as you and what I did was went and got a gallon size can of carberator cleaner dip and and took everything out/off the carb that I could and set the carb body in there and let it sit over night. I took it out the next day and cleaned it out with carb cleaner in a aerasol can and shot all the stuff out that may have been stuck in it. I used 1.5 cans. I put everythign back togetherand now it runs like a champ. I hope this helps

[La 450 smoka]

Thanxx man.I guess Im in the wrong place for this question,oops.

[2003LimitedBanshee]

Yeah, try the jetting and exhaust for more response. But I would say you are most likely lean. As you decrease elevation you are going to want to jet up. Plus with your port job you would want to jet up also. Since you have it I would throw the 340's in and see how it responds. I run anywhere from 300-330, depending on the time of year (temp) and elevation (sea level to 4000'+), and I don't have any port work at this point. At 2000' only pipes/silencers, reeds and removing the airbox to run a UNI 2:1, I was lean with 300 mains. So try the 340's since you've got them, and go from there. Depending on the port job, it may still be lean, or may be fat, but a read on the plugs should give you a good idea at that point.

[La 450 smoka]

Yeah, try the jetting and exhaust for more response.  But I would say you are most likely lean.  As you decrease elevation you are going to want to jet up.  Plus with your port job you would want to jet up also.  Since you have it I would throw the 340's in and see how it responds.  I run anywhere from 300-330, depending on the time of year (temp) and elevation (sea level to 4000'+), and I don't have any port work at this point.  At 2000' only pipes/silencers, reeds and removing the airbox to run a UNI 2:1, I was lean with 300 mains.  So try the 340's since you've got them, and go from there.  Depending on the port job, it may still be lean, or may be fat, but a read on the plugs should give you a good idea at that point.

411654[/snapback]

 

Hey man appreciate the help!

[Banshee~]

You kinda did things backwords, but anyway put in the 340's and see what happens. I would order 350's and 360's also. Dial in the mains and then work you way down because it could change the settings from 0-3/4 throttle.

[La 450 smoka]

Well I took my carbs off ant thoroughly cleaned them,put in the 340's and took her for a rip.It runs way better,maybe a bit rich,but not much(I aint got enuff room where I'm at to get outa 3rd,so a plug test is not gonna be accurate?).Well,it still wants to cut out a bit and pop under hard acceleration in the low to mid rpms(cant tell if it's on top cause it rips through so fast:))Could my ignition system be acting up?It's only doing this under full throttle at low to mid rpm's.

[2003LimitedBanshee]

I wouldn't really expect it to be an ignition problem. I've had no problems with my ignition to date, so it would have to be more of a defective part situation. Which could happen. When you say the problem is at the lower rpm range at full throttle I assume you must hammering it to full throttle pretty quick? Otherwise I would think the revs would already be up by the time you got to full throttle. If it is at full throttle this will throw out my next idea, but I might try a needle adjustment. The reason I say this is because of the "popping" you described. I know this will sound dumb, but on one short ride down my road after the bike had warmed up for a minute or two I started to lean into the throttle a bit, and it gave me a small pop. I soon realized I was an idiot and forgot to turn the fuel on. ( I know call me stupid). Anyway the lean condition in my case was what caused the little pop, luckily no damage for my stupidity. So the pop makes me think it could be leaning out a little. If you aren't in fact at full throttle, you may be able to tune this away by raising the needle one position towards the pointed in. If you've got the space and clean area it will only take you a few minutes to make this adjustment and check it out. Let us know...