urgent help needed please

[bansheeboyo]

ok so my stock carb packed up so i bought a 38 air stryker hooked it up 2 my big and it ran rather slugish after a day of riding the bike stalled and wouldnt start plug was major black put a new 1 in and the bike will only idle when i give it gas it just dies any 1 know whats the wrong im about sea level and average temp is 12 - 15 degreese cellsious in summer
mods see bellow in signature thing nothin major
cheers scott

[bansheeboyo]

oh i forgot to mention i run 160 ml of putoline mx 5 to a gallon of fuel

[rustyATV]

What's your jetting?

Pilot #
Needle (+ clip position)
Main #

[bansheeboyo]

it is 55 piolet
170 main
3rd clip frm top needle is a DDJ
cheers for the help
scott

[Dave83]

Try a 165 main with a 50 pilot and maybe raise the clip 1 notch.On my 310,Im running a 170 main w/ 50 pilot.One other thing,you using a lid on your airbox?

[bansheeboyo]

no lid on air box
it never came with the bike
thanx for the help like
cheers scott

[bansheeboyo]

i also have a uni filter if that makes a diffrence
scott

[cdrookie]

you need to do some plug chops to get the jetting right. it's gonna be hard for someone across the pond to give you correct jetting advise. your gas quality and oil(that i never heard of) can make a difference. sounds like you're rich which is a good place to start.

[bansheeboyo]

this is going to sound stupid but what is plug chops ?
i finnaly got it going 165 main 52 piolet 2nd clip
cheers for the help
scott

[Dave83]

Plug chop.Run the bike up in 5th or 6th gear and while holding it wide open,kill the engine and pull in the clutch at the same time.take the plug out and see what it looks like.Black indicates rich jetting,whiteish means lean.You are looking for a brownish tan(like a paper sack) color.This lets you know that your main jet is right.I run mine more on the richer side,plug is not black,but still darker than the "spot on" tan color.

[LONG-ROD]

I run a 179 main and a 55 pilot and I t is sea leavel and 90 degree F on a 67.5 mill bore and a 39 pwk, If you have to lean it out so far as 165 I would look other places like pull the plug cap off and make sure there is some good exsposed wire, and make sure your carb is opening all the way, and make sure you have clean as new filter, and sure you can at least put your finger in the pipe where it meets the silencer, I also run a 19 plug gap and a br9es plug. Hope this helps.

[rustyATV]

Originally posted by bansheeboyo
it is 55 piolet
170 main
3rd clip frm top needle is a DDJ
cheers for the help
scott

That sounds like an out-of-the-box jetting; my 38 Air Stryker came with a DDJ needle, and that's way rich.

Just as a for-instance, because your conditions are certainly going to be different, here's what I run

Summer
Pilot:42 (Tuned with air screw. Actually, might be a 40, it's been a while)
Main: 160-162
Needle: CEJ
Clip: 2nd

Fall/ Early Winter
Pilot:45 (Tuned with air screw)
Main: 165 (or better, depending on how cold)
Needle: CEJ
Clip: 3rd

I run at about 1000ft with an 0.080 over piston, woods porting and low and mid range pipes, depending on the day.

Also, keep in mind you should do plug chops for all ranges of throttle (1/8th, 1/4, 1/2, 3/4, full) as this will help tune in the entire carb. Here's a graphic that will help, either tune better, or confuse you.

http://img.photobucket.com/albums/v11/hoppy/calchart.gif

[rustyATV]

By the way, a couple of years ago Duncan racing spilled the beans on their two-stroke tech secrets. Among them is this "How to" for jetting Keihin Carbs.

http://duncanracing.com/techfaq/Tech_keihin-carburetion-jetting.phtml

I especially like this note


- Silencer Color: Always take note of the silencer exhaust color where the exhaust exits the silencer. Inspect the core and corresponding end cap. Colors will be similar to plug color.