Jetting questions

[fitz18]

Hello all at bansheehq. Hope yous are all keping well. Ive had a couple of jetting questions that have always been on my mind so here goes.

 

I rebuilt my bike (new wiseco's and mild port job on cylinders). Im trying to get my jetting perfect so here's my questions:

 

1. If I dont need the choke to start the engine from cold am i rich or lean?? I needed the choke yesterday but today I didnt. Started 1st kick. Weird i thought.

2. Does needle height affect idle?

3. Am i close with my jetting?

 

I have dmc aliens, k & N with snorkle removed from lid (but lid still on), 240mains, air scrw 1 1/2 out, needle on 2nd clip from pointy end. Everything else stock. Im at sea level and its around 60f here in ireland.

 

Im getting a bit of bogging at low rpms but pulls really well at high rpms.

 

What ya's all think??

 

Thanks

[sheerider1026]

sounds like you pilot jet and air screw are spot on. but a 240 main seems very lean to me.. you should be around a 270 or 280.. just my .02

[sheerider1026]

sorry about the spot on on the pilot, if u are bogging i would try raising the clip up a notch or two on the needle and put a 270 main in. raising the clip (which will lower the needle) will lean the bike out some, but will probably fix the bogging, also switch the main out for a 270 or 280 so your top end will not be lean.. ..

[530grafix]

if your bogging on the bottom your "fat'. if its breakin up on the top then you need to go up on the main. IMHO with the airbox lid on your main seems close. try leaning out the bottom first, on adjustment at a time. :biggrin: i was running 280's with the lid off and pod filters. the best thing to do is check your plugs.

Edited December 8, 2007 by 530grafix

[brian]

1. If I dont need the choke to start the engine from cold am i rich or lean?? I needed the choke yesterday but today I didnt. Started 1st kick. Weird i thought.

2. Does needle height affect idle?

3. Am i close with my jetting?

 

If you don't need choke to start, the pilot is set too rich, choking richens the mixture

to aid in starting the motor when it is cold. Turning the air srew out will lean that setting,

but is sounds like you may need to go to the next lower pilot jet.

The needle height does not affect idle. Needle controls 1/8 to 3/4 throttle position.

 

Your current needle setting is almost as rich as it can be. Moving toward the blunt end of

the needle will lean out the low to mid range. You could probably move to the middle

clip position to see if it pulls better in the low range. Maybe even 2nd from the blunt end.

You can do a plug chop (see plug chop on the threads here) for mid range, follow the same

directions, just run it in the mid range, instead of full throttle.

 

Also, I agree that the main might be a little lean. I just dont know because I dont know what

your air quality is over there. Temp, humidity, bar.pressure all affect mixture as well as elevation.

 

Choose only one circuit to work on first. Get it set and then move on to the next. That will keep

you from pulling your hair out.

I really think your best option is to run a plug chop for mains first before doing anything else.

I like to work on the lean condition first.