What size Keihin pilots do you run?

[Blaner]

Still battling with jetting my OKO30...its pretty decent on top end with a 168 and on the bottom clip with a JJH needle, but pilot is where im battling with a bog between pilot and needel transition.

ive tried them all up to a #58 which seems ok but the bog is only eliminated at 1/2 a turn or less out...which indicated that pilot is too small...

I have a DIY'd old #42 which has been drilled out to an unknown size but is visually much bigger than the #58, ive found very good results with this jet but i have to have it 3 turns out to idle with the idle screw all the way in...meaning its too rich! but it performs well and the bog is gone

So, i think i need like a #68 or #70! which in my mind is far too big for what a blaster should use...

I have no air leaks, motor is solid with a brand new top end, crank seals are solid and the reed cage is sealed with RTV silicone. leak test hold over night!

I made a rubber gasket for the cap of the carb because i found it was leaking there and i put an o-ring on the choke to seal it up. so the carb cannot suck any un-metered air.

still i have this situation...

i am ported etc as in my sig.

Any opinions as to why i need such a big pilot? i also think i need a richer needle, like a JGH or so... any ideas?

this jetting is becoming a pain...

 

[super noober]

man i only got a 50 in mine but its a 34mm carb.. thats a wierd needle, have u ever tried a different one?

 

[sicivicdude]

Still battling with jetting my OKO30...its pretty decent on top end with a 168 and on the bottom clip with a JJH needle, but pilot is where im battling with a bog between pilot and needel transition.

ive tried them all up to a #58 which seems ok but the bog is only eliminated at 1/2 a turn or less out...which indicated that pilot is too small...

I have a DIY'd old #42 which has been drilled out to an unknown size but is visually much bigger than the #58, ive found very good results with this jet but i have to have it 3 turns out to idle with the idle screw all the way in...meaning its too rich! but it performs well and the bog is gone

So, i think i need like a #68 or #70! which in my mind is far too big for what a blaster should use...

I have no air leaks, motor is solid with a brand new top end, crank seals are solid and the reed cage is sealed with RTV silicone. leak test hold over night!

I made a rubber gasket for the cap of the carb because i found it was leaking there and i put an o-ring on the choke to seal it up. so the carb cannot suck any un-metered air.

still i have this situation...

i am ported etc as in my sig.

Any opinions as to why i need such a big pilot? i also think i need a richer needle, like a JGH or so... any ideas?

this jetting is becoming a pain...

I chased a rich condition in my OKO30 for a while with needles and pilots. I ended up settling a little bit on about a 50 pilot and a thicker needle. It seems like every move I made on the needle, the pilot circuit got worse.... I think the carburetors in general are kind of a "risk it" type venture. Some work flawlessly, some not so much.

A 168 main also sounds terribly high for a blasty. It sounds like ALL of your jetting is way rich, double check that float height again.... it should be 19mm from bowl sealing surface to the bottom of the float with the float JUST touching the needle (not pushing the spring in at all) Turn the carb on it's side to make sure the weight of the float cannot push the spring in at all.

 

[Blaner]

the JJH is a genuine Keihin needle, the stock OKO needle N80F is very very very bad and is pretty much unrideable.

Ive also used the banshee needle which was ok on the richest setting but it is fairly short compared with the JJH.

if i go leaner it just bogs itself to death. i cant figure this out

 

[Blaner]

il check out the float height again although i have set it a couple times at 19mm

 

[slickerthanyou]

I had a huge pilot in my 30mm. and still wanted more, i think i was at 62 and tried 70 with little change. My main liked 168 too, plug chop showed rich but when it got hot (summer) it would surge at idle (like an airleak) but test after test was all leak free. Then I adjusted my slide to 3/16 open with out any throttle tension, was able to drop to a 58 pilot and 2 turns out, still had the surge at idle only when it got hot., but ripped good through all phases. I then decided to go to a 35mm after talking to a couple guys and haven't looked back since!

 

[Blaner]

mmm, seems like my scenario slick, tell me, when you talk about adjusting the slide did you do it by adjusting the brass nut ontop of the carb or by turning in the idle/slide adjuster screw?

did you use a spacer under the slide and adjust till it was right? doesnt that make it idle really fast?

 

[Blaner]

FYI with my old stock mikuni i was running a 330 and a banshee needle mid clip with 35 pilot....but a direct comparison of jet sizes is irrelevant because the OKO flows more air than the 26mm Mik

 

[slickerthanyou]

mmm, seems like my scenario slick, tell me, when you talk about adjusting the slide did you do it by adjusting the brass nut ontop of the carb or by turning in the idle/slide adjuster screw?

did you use a spacer under the slide and adjust till it was right? doesnt that make it idle really fast?

I used a 3/16 drill bit put it under the slide adjusted the top brass fitting, and then adjusted the idle screw back to get close to perfect idle.

They are suppose to come with 1/8" opening when i got mine it was fully closed and i used the idle screw to adjust that, but had a crap load of trouble jetting it, talked with a few guys and Ken, tried the 1/8" opening first then went up to 3/16 then 1/4. As suspected 1/4 was too much and couldn't control the idle, settled at 3/16 seems to be my best point! This was before I realized there were different slides available! I would of like to try a higher number slide. Seems as though the cutaways are way different. There was a post on here a while back from I think turbowrenchhead he bought a 35mm and it came with the wrong slide. Ya may want to call CPW and see what slide number they recommend.
Here is a chart for keihin slidesVVV-
I tried to put the image up but ya can't read it so here is the link.
http://www.sudco.com/Diagrams123/exppwk.gif

 

[Blaner]

ok i fiddled with the slide, but to no conclusions, float is 19mm exactly.

Tried a few things:

1. DIY pilot 2 1/2 turns out and JJH needle on richest...seems ok, not bogging but has a flat spot just off closed throttle.
   
   
   
2. Tried DIT pilot 2 1/2 turns out and JJH needle in Middle, seemed better. but still flat
   
   
   
3. Tried 58 Pilot 1 1/2 turnout and JJH needle on Middle...BOG!
   
   
   
4. Tried 58 pilot closed and JJH needle in Middle...Quite good but flat spot still evident, no bog tho.
   
   
   
5. Tried 58 pilot 1/2 turn out and JJH needle in Middle, BOG!

SO...i think i will try a BEEG pilot, il use my DIY till i get like a 68 or so, then lean out the needle somewhat, il go up to leanest on the JJH then if needs be, move on to the OKO N80F.

 

[slickerthanyou]

That sucks! i say get it at is best then get on it and beat the hell out of it show it who's boss, Then order more parts and fix it!!!!

 

[Rich]

Is the jjh richer than the n80f.Now that Ive found this thread Ive been in the same boat with exact same results with the n80f.They were supposed to send me a jjj but instead got a jjh.I dont even know if I want to bother messing with it anymore.lol uffggg.

 

[wwholden]

I used a 3/16 drill bit put it under the slide adjusted the top brass fitting, and then adjusted the idle screw back to get close to perfect idle.

They are suppose to come with 1/8" opening when i got mine it was fully closed and i used the idle screw to adjust that, but had a crap load of trouble jetting it, talked with a few guys and Ken, tried the 1/8" opening first then went up to 3/16 then 1/4. As suspected 1/4 was too much and couldn't control the idle, settled at 3/16 seems to be my best point! This was before I realized there were different slides available! I would of like to try a higher number slide. Seems as though the cutaways are way different. There was a post on here a while back from I think turbowrenchhead he bought a 35mm and it came with the wrong slide. Ya may want to call CPW and see what slide number they recommend.
Here is a chart for keihin slidesVVV-
I tried to put the image up but ya can't read it so here is the link.
http://www.sudco.com/Diagrams123/exppwk.gif

Im having a similar problem trying to dial in my pilot. I have the 33mm PWK and I adjusted the idle by turning the adjustment up at the throttle box. But when turning the air screw and waiting 30 seconds between each half turn it has no effect. Only stalls out when its screwed all the way in. But from 1/2 turn to all the way out = no RPM difference. Maybe I have the idle adjusted wrong? Should I try the 3/16 drill bit method and set the idle with the brass screw on top of the carbs lid?

 

[Rich]

Just went out and tried the jjh.Running 55p and 158m.No porting.Needle in 4th clip position and yup it bogs durring low to mid transision.I could lower the pilot jet to cure it but as is with a richer pilot it still surges like it has an air leak after ripping and closing the throttle.A little richer than the n80f but not liking the bog.I think middle clip is the sweet spot on the jjh as well but increases surging when getting off throttle.Bummer.I think its one more needle then Im just going to scrap this carb......Idk lol.I gave up on this thing a while back not sure why Im so determined to get it to work.Well new carb and bad economy leaving me with less money than the norm8-|LOL..Not sure imo everything points to an air leak but every thing has been sealed with the appropriate sealant from read cage to the exhaust manifold.Just cant seem to lean the pilot out with out the surging other than that runs ok.Idk sure wish I had the funds just to get another mikuni.B)