UPDATE: Keihin 34 PJ Project....

[lassek]

Hi guys.

I have now changed the mainjet to 150 from 155. That seemed to help! .. It can now rev higher and cleaner without bog.. but it still bogs at very high rpm.....(This is with lid:ON).

I did try to remove the airbox lid... I seemed like its getting way to much air then.. Ex. if it idles and you suddenly pull full throttle.. It chokes in air.. (this is with the seat off testing.. It seemed better with seat on, lid off.)

But i think the best result was with the lid on and the 12 vents..

I still have a 145 main jet.. Maybe I should try that?


Can someone confirm that a mainjet #145 for Keihin 34 PJ will not be too lean? (because its a big jet?) OR is it possible to run lean with this size?????

Stock jet for the PJ 34 is a #152....

What I mean is can I say to myself a mainjet #145 is in an area where its not possible to run lean? Or can that happen with this size?


Lasse

 

[mystahagy]

I recently got a flotek trail port on stock bore, and added in most of the motor mods listed in my sig.

I'm still trying to clean out my low end, however I've gotten the main jet down to a 145 right now and the color is coming up excellent on the plugs. This is even with a large clamp on Uni filter routed to my airbox. But yeah, mine idles well and screams up on the pipe, but it spits and sputters through the midrange unless you baby it. Tried every needle clip position and airscrew from 1/2 to 3 turns out. :-/

Give that 145 a try, your plug chop will determine if it's right for you.

 

[mr_3_0_5]

im running a 155 and clip in the second from the point to richen the top end. try that.

 

[doc_speeder]

I just put my PJ on last night. Starts, runs pig rich (which I expected as the main is a 160), but will not run without some throttle, just dies right off. What pilot are you guys running?

 

[lassek]

mystahagy: I actually think the 145# is the way to go! .. because i have just read an article here on the forum, and mine dosent bog but sputters at high rpm .. and that could very well be a sign of to big jet. I just wanted to know if I in any way could run lean with that size or its 100% safe..

Mr. 305:

Are you runing without lid? Mine sputters alot with 155# but that was with lid on, it dident test it off. I must admit I really want the lid on! due to dust and dirt.


Also I seemed to have a little difficulty having it to idle properly. I just need a little more "throttle" in idle.. but i tried the idle adjuster with not much luck..
(could this also be because i dont have the right gascable in and therefor not the "black rubber" "thingy" on top of the carb to seal it off from dirt, false air etc.. )

 

[djack12]

the idle on on PJ can be difficult to adjust at times. if you get it to where you think the idle is correct, it will bog. the idle on the pj is adjusted by the chock valve. i just screwed mine all the way down shut, and adjusted it with the throttle cable. works perfect. running a 150 main and it rips.

 

[lassek]

DJACK12:

Thats sound good! .. I will try that.. did you adjust via cable at the throttlebox? or at the top of carb?

I now have the 150 and i can take full throttle perfect.. but at idle if I rev it in absolut top rpm it sputters a little.. this is normal ? Or is it impossible to not have just a little ...


and i forgot .. what are your engine specs .. ?

 

[djack12]

a slight hesitation or bog on the very top end means its a little rich. try a needle clip adjustment. i sent you a pm with my specs.

 

[lassek]

ok your IDLE : did you adjust via cable at the throttlebox? or at the top of carb?