Fastdadtsmith Posted September 20, 2006 Report Posted September 20, 2006 (edited) I am a first time poster, and need your help with jetting. I have a 65 mm cub cylinder, 5mm long rod crank, mossberger reeds, Noss Head, 18 cc domes, PJ 34's, CGL needle on 5th clip, 168 main, 55 pilot, 8 degrees advance, FMF Gold pipes (I know from reading they're next to go) want to go T-5's I think for all around ride. I can not get it to idle. Have tried air screw everywhere from 1/2 turn to 6+ turns at 1/2 turn increments, and it will not idle. If I crack the throttle just a hair, stays smooth, and revs instantly. No hesitation. I have not ridden yet, so I do not know how it will do under a load. I'm at 2500 ft, do not have a compression number yet. Thanks for looking.... Edited September 21, 2006 by Fastdadtsmith Quote
wesw Posted September 21, 2006 Report Posted September 21, 2006 (edited) for some reason cubs dont like fuel down low and mid as much as others. mains thats another story. i would try some 50 pilots, cel or dek mid clip, and 150 mains would be a good start. depending on your elevation. if you pack the air screw out 3 turns and still no idle the pilot is too big. also need to sync your carbs verywell. there are tools for that. just read your at 2500 ft. you might need some 48 pilots or 45s. Edited September 21, 2006 by wesw Quote
Fastdadtsmith Posted September 21, 2006 Author Report Posted September 21, 2006 Thanks for the input. I had read many posts from you recommending the CEK needle so I just received a CEK and a DEK. I'm going to try these, but after running up and down the street a few times discovered coolant coming up my head bolts, no o-rings on hand, so I'll wait for them to come. Do you have a clip position suggestion? Thanks again....... Sorry wesw, just read it again, "mid clip" ........ Quote
Fastdadtsmith Posted October 2, 2006 Author Report Posted October 2, 2006 OK, more testing completed. I switched needles to a CEK, mid clip, top clip, bottom clip. Pilot jet to a 48, left the main alone for safety, no difference. I played with the carbs for a full day today and ended very frustrated. Then I went down the street and borrowed a compression gauge to find I only have 115 psi in both cylinders. I have the Noss head with a spacer plate, maybe the spacer plate is the problem? But could you re-visit your jet recommendations based on these numbers, or am I in compression denial? Thanks.... Quote
terboed Posted October 2, 2006 Report Posted October 2, 2006 idle adjustment on pj carbs is made by turning the choke knobs. in case you dident know. Quote
jbooker82 Posted October 2, 2006 Report Posted October 2, 2006 How many turns out on the idle / choak knobs are you? Mine are around 7 to 8 turns out from fully closed. Quote
blueshee03 Posted October 2, 2006 Report Posted October 2, 2006 i'm at 2500 ft also and ran 34 pj's for awhile on a 358 stock cylinder, stoke stroke with a big reed conversion and +5 timing and 115 octane 175 pds compression .i ran del needles in middle clip ,148 mains and 42 pilots and air screws 2 full turns out. Quote
Bansh-eman Posted October 5, 2006 Report Posted October 5, 2006 i also have 34 pjs... and those thing where a monther fuker to get to idle! make sure your floats are set the the right height and your got good jetting for your evel... turn your screws all the way in and use the adjusters to get it to idle... once you got it idling tunr it in a half turn so it wont idle from the cap adjusters and then use your choke to fine tune it ... they will idle but it takes some time getting them in there... also if you dont have a carb sync tool GETONE!!!! my buddy spent over an hour syncing his carbs "by eye" and he swore it was on... 2 min later with the sync tool and he wasnt as confident as he had been a few min prior... Quote
RILS Posted October 6, 2006 Report Posted October 6, 2006 I am a first time poster, and need your help with jetting. I have a 65 mm cub cylinder, 5mm long rod crank, mossberger reeds, Noss Head, 18 cc domes, PJ 34's, CGL needle on 5th clip, 168 main, 55 pilot, 8 degrees advance, FMF Gold pipes (I know from reading they're next to go) want to go T-5's I think for all around ride. I can not get it to idle. Have tried air screw everywhere from 1/2 turn to 6+ turns at 1/2 turn increments, and it will not idle. If I crack the throttle just a hair, stays smooth, and revs instantly. No hesitation. I have not ridden yet, so I do not know how it will do under a load. I'm at 2500 ft, do not have a compression number yet. Thanks for looking.... I run this same motor setup with trinty pipes at 900ft and had the same problem.Drop your pilot down to about a 48 or 45 im running a cel needle on the top clip im going to richen it up a bit when i have time but havent really had a chance to dial it in since i built the motor but i could not get it to idle until i leaned the needle out.You also sound pretty rich on the main to me im at 155 but like i said i havent really had time to dial it in but i did check it and its not that far off. Good luck Quote
Fastdadtsmith Posted January 18, 2007 Author Report Posted January 18, 2007 I have tried a few different combo's and still not real happy with the results. I am back to 55 pilot, CEK mid clip, 168 main. When I had 155 main in it felt like it was falling off up top which I thought I was running out of fuel, but this sounds to be rich doesn't it? Still have not played with idle too much, very hard to start now. I am going to dyno it in a couple of weeks at a local shop who stocks plenty of jets, but they do not stock needles. I have a CEK, DEK, and CGL needles, I would like to take two or three others to try. Could you recommend any others to try? Also switched to Trinity pipes, good mid range, poor low and top. Thanks for all the input. Quote
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