530grafix Posted June 3, 2008 Report Share Posted June 3, 2008 Okay heres the problem. I have tried everything that I can think of and now I'm looking for some help from all of you! First Its a 4mil cub with 35's,shearers, comp 175 60ft asl. Heres the problem.......Had 158 mains in this winter. temp warmed up and went to 155's ( 48 pilot 1.5 turns out) seemed a little fat with the 158s. took it out this weekend, grabbed 2nd, then 3rd. it fell on its face like it was lean. so I fattened it up on the needle one clip. ran good! rode for a few hrs, let it sit, took off again and it felt like it was lean in the medrange again! AARRRRGGGGGGGG! What the fuck!!! im stumped. I covered all the basics, mic'ed the float bowls, comp test, leak down test. And now the next problem........I have a digitron (egt sensors) in the cub and im getting a 600 degree difference from the left to right side. wide open throttle i get 250ish on the left side and 900 on the right. I tried swapping the sensors from one pipe to the other to see if i had a bad sensor, but the problem persisted. As for this problem i checked the ignition, and the plugs. both were fine. So if anyone has any other ideas feel free to shoot them over! thanks, Tony Quote Link to comment Share on other sites More sharing options...
moneybags Posted June 3, 2008 Report Share Posted June 3, 2008 Try swiching your carbs from left to right. See if that makes the EGT read any different. Did your carbe give you any shit this time asfar as overflowing? Quote Link to comment Share on other sites More sharing options...
530grafix Posted June 3, 2008 Author Report Share Posted June 3, 2008 Try swiching your carbs from left to right. See if that makes the EGT read any different. Did your carbe give you any shit this time asfar as overflowing? no no overflowing. ill try switching the carbs tomorrow. My neighbors will call the fuzz if i start it again tonight!!!!! Quote Link to comment Share on other sites More sharing options...
dajogejr Posted June 3, 2008 Report Share Posted June 3, 2008 Couple things. You running race fuel? How much timing? What needle is in there? Compared to my old cub setup (same as what you have) you are way fat... I think it's time to start checking electrical...to be honest. Also, clean and clear gas lines to the carbs and the screen in the tank ok, clean? Quote Link to comment Share on other sites More sharing options...
530grafix Posted June 3, 2008 Author Report Share Posted June 3, 2008 Couple things.You running race fuel? How much timing? What needle is in there? Compared to my old cub setup (same as what you have) you are way fat... I think it's time to start checking electrical...to be honest. Also, clean and clear gas lines to the carbs and the screen in the tank ok, clean? Runnin race fuel. and timing was @ 7 so I backed it down to 5. screen is also clear and new fuel lines. thanks for your prompt responses.. oh ya CEL needle was originallly on middle clip. Pickup gap is also at .030.... Quote Link to comment Share on other sites More sharing options...
Geoff Posted June 4, 2008 Report Share Posted June 4, 2008 (edited) I've got a 7mil on gas with 35's with some port work and mine loves fuel. I running a 50 pilot, CGL on the 2nd clip and 170 mains. I originally had it jetted 162/50/ middle clip which was fine for my heat cycles but once I got it to the hill it ate up the left side piston in 3 passes and my plugs were rrreeeaaallly clean. By the way I'm at sea level and about 60 for temp. Also forgot to say I'm running 18cc domes, +7, with CPI inframes. Edited June 4, 2008 by Geoff Quote Link to comment Share on other sites More sharing options...
blue02 Posted June 4, 2008 Report Share Posted June 4, 2008 You may have an air leak, which is causing such a temperature difference from one side to the other. One side may be running lean, might want to do a leak down test to rule an air leak out. Quote Link to comment Share on other sites More sharing options...
J-Madd Posted June 4, 2008 Report Share Posted June 4, 2008 Couple things.You running race fuel? How much timing? What needle is in there? Compared to my old cub setup (same as what you have) you are way fat... I think it's time to start checking electrical...to be honest. Also, clean and clear gas lines to the carbs and the screen in the tank ok, clean? If swapping carbs doesn't change the problem side, swap plug wires. If neither changes the affected side you've ruled out jetting or electrical. That leaves air leak, head or base gasket leak, low compression on one side/hole in piston, etc. Quote Link to comment Share on other sites More sharing options...
moneybags Posted June 5, 2008 Report Share Posted June 5, 2008 (edited) I am pritty sure the pick up gap should only be around .018 to .020. Might try checking that agin. Edited June 5, 2008 by moneybags Quote Link to comment Share on other sites More sharing options...
PassionRE Posted June 5, 2008 Report Share Posted June 5, 2008 Runnin race fuel. and timing was @ 7 so I backed it down to 5. screen is also clear and new fuel lines. thanks for your prompt responses.. oh ya CEL needle was originallly on middle clip. Pickup gap is also at .030.... 1st problem....Your CEL's are almost certainly too lean, try a DEK. What intakes are you running? at least one brand I know of will read lean on the mid with normally accepted jetting ranges. Also, its not terribly uncommon to read hotter EGT's on the right side...easily combatted with a larger main as long as your certain no air leaks exist....Jim Quote Link to comment Share on other sites More sharing options...
530grafix Posted June 7, 2008 Author Report Share Posted June 7, 2008 i have tried switching the carbsand no difference. Ill try snother leakdown test again. i did try a leak down test initallly and it was fine... ill try the needles next.. thanks for all the responses.... ive been busy, my 10yr old was diagnosed tuesday night with type 1 diabetees. Quote Link to comment Share on other sites More sharing options...
dajogejr Posted June 7, 2008 Report Share Posted June 7, 2008 Sorry to hear about the 10 year old. I don't know the difference between the different types, but hopefully with treatment catching it early will pay off. Dumb question, but does your leak down tester have a check ball in it? I used a low pressure tire gauge for mine, but i had to remove the check ball... 6PSI for 6 minutes is a good rule of thumb, up to 1PSI loss per minute is acceptable. Quote Link to comment Share on other sites More sharing options...
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