bansheeyfz Posted April 30, 2007 Report Share Posted April 30, 2007 Runs decent in first 3 gears but breaks up on the top in 4 5 6th? Quote Link to comment Share on other sites More sharing options...
burleybanshee Posted April 30, 2007 Report Share Posted April 30, 2007 I have those carbs, but i'm running them on a dune ported 4 mil with t5. Found 162 to be just a touch rich but is perfect at sea level. I have 58's for pilots in right now with the middle position on the neddle. Was running 55 pilot with the neddle all the way up and was just a little lean on the dyno sniffer under load. It sounds to me like you are a little rich on the mains and need to drop down a size. What do you have in it now, the 155's? Quote Link to comment Share on other sites More sharing options...
bansheeyfz Posted April 30, 2007 Author Report Share Posted April 30, 2007 I have those carbs, but i'm running them on a dune ported 4 mil with t5. Found 162 to be just a touch rich but is perfect at sea level. I have 58's for pilots in right now with the middle position on the neddle. Was running 55 pilot with the neddle all the way up and was just a little lean on the dyno sniffer under load. It sounds to me like you are a little rich on the mains and need to drop down a size. What do you have in it now, the 155's? i forget i would think it is lean?oh and it back fires. Quote Link to comment Share on other sites More sharing options...
dajogejr Posted April 30, 2007 Report Share Posted April 30, 2007 If it backfires it's probably lean... What size jets are in there now? Quote Link to comment Share on other sites More sharing options...
Geoff Posted May 1, 2007 Report Share Posted May 1, 2007 I'm running 158/ 55/ 4th currently. I started 158/ 52/ 3rd and have been trying to get rid of a stumble when you stab it while cruising. I'm going to go back to the 3rd clip and try either a 50 or a 58. I haven't had to jet much so I'm playing the trial buy fire game,lol. I'm at sea level with aggressive dune port, CPI's,vf3's, 19's, +7. Quote Link to comment Share on other sites More sharing options...
jmd0346 Posted May 2, 2007 Report Share Posted May 2, 2007 If it backfires it's probably lean...What size jets are in there now? Hmmm. Usually a rich condition causes a backfire. It loads up in fuel and backfires. Maybe Im missing something. Please expain. Im really interested. Quote Link to comment Share on other sites More sharing options...
dajogejr Posted May 2, 2007 Report Share Posted May 2, 2007 Backfire can be caused by lean or rich condition... In my experience....it's more often than not lean. But...looking at his jetting, I agree and think it's too rich. Your pilot is too rich... I don't even use that large of pilots in a cub motor. Drop the pilot down to a 48. The main won't help you when you stab it off idle, though... Drop the pilot...get a few sets of plugs, and do a plug chop to dial your main in. I'd bet you end up with a 150 to 155 main. If it's stumbling when you stab at it...it's probably too rich off the bottom... Quote Link to comment Share on other sites More sharing options...
burleybanshee Posted May 2, 2007 Report Share Posted May 2, 2007 I have read other peoples questions regarding pilot sizes for other pwk's and wondered why cpw sends 55's and 58 with the carbs. Only thing I can think of is they use pwk 28 neddles in the oko30's. Different neddle size and shape as well as maybe the idle screw openeing for fuel is different size in the 28's compare to 33 and 35's. I know mine is a 4mil, but i had to go up to a 58 from a 55. Had great responce with the 55's just a touch lean on the sniffer. Am i wrong in tuning the idle and off idle on the dyno. You can't plug chop your pilot to see if you are a jetted correctly. I think the 30oko's might be a little different than larger pwk's and can't associate the pilot numbers from one to another for tuning? The mains though are still apples to apples I believe. The guy at carb parts wharehouse sent the 55 and 58 when i told him i had a standard bore and stroke shee. He told me 55 should be perfect for my application and threw in the 58. Went to the 4mil and needed the 58's. Dajogejr, I'm not trying to go against you. You are one of the most knowledgable persons on here that is willing to share and help. You helped me out and I appreciate it. I think you are rich on your mains and need to play with the neddle some more on the 55 pilots. Just my two cents. Quote Link to comment Share on other sites More sharing options...
dajogejr Posted May 2, 2007 Report Share Posted May 2, 2007 Hey...no offense taken, and thank you for the kind words. On most bikes I've seen, be it a stock motor or a cub, a 50 pilot or smaller were used. This is at or near sea level, normal riding temps. Hell...I'm only running a 52 or 55 as my pilot in my 39's and I'm on alky.... Since he mentioned bog as he stabs it off idle...that tells me the air screw/pilot circuit are rich...coupled with my experience on jet sizes for the PWKs.... I think you're headed in the right direction.... Quote Link to comment Share on other sites More sharing options...
bansheeyfz Posted May 3, 2007 Author Report Share Posted May 3, 2007 if i out my toomey needles in will it help? Quote Link to comment Share on other sites More sharing options...
dajogejr Posted May 3, 2007 Report Share Posted May 3, 2007 Far as I know...Toomey doesn't make needles for PWK series carbs, only Stockers....that could be your problem right there. Quote Link to comment Share on other sites More sharing options...
Geoff Posted May 5, 2007 Report Share Posted May 5, 2007 The needles in mine are N68a. dajogejr, from what I know the stumble most likely is from being rich....It's just that Cam@Redline who redid my port work and who I got the carbs thru said that 158/52 is usually pretty good for his setups. I think I'm just fighting it even though I know all motors are different. Should I try a 50 or go straight to a 48? Not trying to hijack since we have the same carbs I thought it would be ok. Quote Link to comment Share on other sites More sharing options...
dajogejr Posted May 5, 2007 Report Share Posted May 5, 2007 Cam knows his shit...no doubt. But he, just like myself or ANYONE can only get you close. I'd bet his jetting recommendations are fairly safe. He doesn't want you to blow up a new motor any more than you do... There's no reason you can't go 50 then 48. It's only a few bucks out of pockets for pilots..no big deal... Quote Link to comment Share on other sites More sharing options...
bansheeyfz Posted May 5, 2007 Author Report Share Posted May 5, 2007 Far as I know...Toomey doesn't make needles for PWK series carbs, only Stockers....that could be your problem right there. Im just using the ones that came in them from CPW. Quote Link to comment Share on other sites More sharing options...
DGFUNNY70 Posted May 6, 2007 Report Share Posted May 6, 2007 Well I'm going to say you really can't compare the larger carbs to these smaller carbs beucase the larger carbs flow more air and can draw the fuel more efficently than these smaller carbs. I would have to guess that the pilots should be pretty close comparison but mains will most likely vary. The N68A needle is the same needle cameron recomended to me. I also know that cascade sells there 28mm pwk's with them already installed in the carbs. The 30 oko's are I believe a real close comparison to the 28mm. I would tell you cameron has proably got you pretty close to what you need to be jetted at but with so many combonations it will some times take some rejetting. I had him build a 4mil for me last year I was useing stock carbs he told me to run with 350 mains 30 pilots and a toomey needle in the 4th clip postion and it ran flawless we dynoed it on his dyno at 75 rwhp and 44 fpt I was VERY VERY happy. This gave me the power to push the 10 paddle extree's I bought very well. I currently have the 30mm oko's that you are all useing I started out with 162 mains 52 pilots N68A needle in the 4th postion 2 turns out on the air screw. The bike ran ok a little rich so I went down to a 48 pilot and it has cleaned up my mid band considerabley but I feel that I could get it a bit beter so I'm planing to raise my pilot to a 52 again and lower the needle to the 3rd clip postion. then I will agian lower the pilot if it does not respond like I expect. I plan to trought it on his dyno again this summer and do some fine tuning I will let you know what I end up at. Quote Link to comment Share on other sites More sharing options...
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