dajogejr Posted April 16, 2006 Report Share Posted April 16, 2006 (edited) Just got my 4 mil cub motor together. I've PM'd Jeff from FAST already...however, I'd like to solicit your input as well. Stock carbs, T5 Pipes, no airbox. This bike, albeit worn out before rebuild, ran very, very strong. I now have new: 4 mil Wisco Crank. 68MM Cubs. Noss head (18cc I think, 180 PSI), Blaster Wisceo Pistons. Yes...double checked the arrow to the exhuast, rings properly installed, etc. I have stock pilots (had 27.5, but turned the air screw about 3 turns out, put stocks back in) I tried 380 Mains, now 350. (Had 330s and ran strong before) Went from Toomey/Dynojet needles back to stock in middle clip (Stock cages, boyseen reeds with almost no gap at all) Starts up first kick, idles great. Put it in gear, and above idle it won't take any gas...just chugs along, it won't get past 1/8 throttle. In Nuetral, revs quick, rappy...strong, as it should. Under load it's dead. Tried the choke trick...an it ran a tad worse. Tried it with 380s and 350s...same thing. Like I said, starts perfect, idles perfect...one kick. Now...the issue. Headlights no longer work at all. Worked fine before. White wire plug connected, as are the single black and yellow wires (bullet connectors) I changed the timing plate (RS) from +5 to 0. No difference at all.... So...whatcha think? Running 110 fuel with 40:1 Maxima Super M...Octane shouldn't be a problem.... I just want to get it running as it should...break her in nicely, and rip some ass at the sand dunes. I'm thinking Stator or Reeds...what you think? Should mention, tried two different sets of brand new NGK B8ES, .030...and triple checked the air gap on the flywheel, it's at .020. Edited April 16, 2006 by dajogejr Quote Link to comment Share on other sites More sharing options...
blueshee03 Posted April 16, 2006 Report Share Posted April 16, 2006 if your running stock carbs on a cub ....why?with a cub setup like you have you should be running 35's at the least. Quote Link to comment Share on other sites More sharing options...
Dinner Posted April 16, 2006 Report Share Posted April 16, 2006 That's what i was thinking,... did you make sure you also have your headlights plugged in When i put my banshee back together i didnt have the plugs in all the way Quote Link to comment Share on other sites More sharing options...
lowriderb Posted April 16, 2006 Report Share Posted April 16, 2006 that stock carbs are being out flowed by the motor.. so basicly the carbs are much much too small to supply the motor, or you jetting is too lean, ive had to run 440's with a stock cylinder motor with the stock carbs.. its not the number of the jet you need to look at just what the motor needs to do anything.. best idea so far would be scrap the stockers and go with some larger carbs.. Quote Link to comment Share on other sites More sharing options...
lowriderb Posted April 16, 2006 Report Share Posted April 16, 2006 oh yeah, the cub motors like to breathe as ive said in other posts, the pipes are going to limit you very much with that motor as well.. at this point im running or have ran 35mm pwk's (gas) and 38mm tm's (alcohol) and it did better with the bigger carbs even before i converted them.. after this next set up is ran with my bike i am going to look to get some 41's and see if there will be a difference with those.. . right now though im having a 5th gear cut for the override and a chassis is going to be built for the motor.. (4mm cub) Quote Link to comment Share on other sites More sharing options...
dajogejr Posted April 16, 2006 Author Report Share Posted April 16, 2006 I am fully aware that I'm limiting the potential of this motor with stock carbs. I'm planning on 35PWKs from Jeff. However, it should run MUCH better than it is now, even with stock carbs. I talked with Jeff, and he said 380 would be a good starting point. It runs like shit no matter what... I know the stock carbs are limiting this thing big time on top end...but, smaller carbs should be more efficient on the bottom end than the 35's...I should at least be able to get it to run ok....if not perfect. I tried the choke trick with the 380s...and it ran worse. That just tells me the jetting isn't that far off...if it is in fact the jetting... To go from 380 to 350 with no difference whatsoever.. Keep in mind...it is doggy OFF IDLE...it won't even get to 1/4 throttle.... Quote Link to comment Share on other sites More sharing options...
blueshee03 Posted April 16, 2006 Report Share Posted April 16, 2006 did you connect the tube between the carbs? Quote Link to comment Share on other sites More sharing options...
rsheppick Posted April 16, 2006 Report Share Posted April 16, 2006 Welcome to my world.... I have a nice pair of 39MM PWK's ill sell you been used matter of 1 1/2 days :-) Mine runs okay just doesn't have the power that I was expecting I think. I am thinking of selling my cub for a 4mill stroker setup. But I want to get mine tuned it and run it against someone with a 4mill cub and see how bad I loose or dont loose Quote Link to comment Share on other sites More sharing options...
Tim C Posted April 16, 2006 Report Share Posted April 16, 2006 that stock carbs are being out flowed by the motor.. so basicly the carbs are much much too small to supply the motor, or you jetting is too lean, ive had to run 440's with a stock cylinder motor with the stock carbs.. its not the number of the jet you need to look at just what the motor needs to do anything.. best idea so far would be scrap the stockers and go with some larger carbs.. 502990[/snapback] They will run on stock carbs and make half decent #'s if jetted right...........I agree bigger carbs will give a big jump in HP. Check out these dynos running stock carbs on a 4mm cub: http://www.bansheeracing.com/cubdynos.htm Quote Link to comment Share on other sites More sharing options...
dajogejr Posted April 16, 2006 Author Report Share Posted April 16, 2006 did you connect the tube between the carbs? 503032[/snapback] Yup...sure did. Golden oldie there!! I even took the stock hose off....got some brand new fuel line, smaller ID, and used a lighter to heat it up...pressed it on for a nice, tight fit. Thanks...though, Blue... I know this motor is goingt to rip once I get it done...I should be pushing 70HP plus...way up from the 45ish I was at before. But...like I said, It won't run past 1/8 throttle or so. Another HQ'er PM'd me about changing my needles. Went from Toomey (Thinner but longer) to stock and still the exact same thing. I noticed a drop of coolant on top of one of the head studs...so, I tore the head off, and I'm going to redo the studs again. I Permatex'd the studs before I put 'em in per Jeff's advise...but...this one still leaked. None in the cylinder...though... I was looking forward to a dune trip this weekend...that might be put on hold. I'll have Jeff overnight me some 35's if that's going to help, but...I think I have other problems I'm not ready to throw another 350 at until I get this $2400 motor the way it should be..... Quote Link to comment Share on other sites More sharing options...
dajogejr Posted April 16, 2006 Author Report Share Posted April 16, 2006 Tim...that is exactly the sheet I looked at prior to my purchase. A&S Racing (Dan Hull) helped design the port layout on these cubs. I KNOW I can get more ponies with bigger carbs, as said. But, it should run ok with stockers.... I believe this is also with a stock cut head, I've been told that Dan rechambers and cuts the stock head...since the cubs cool so efficiently with the larger water jackets and better design. As I said...a 500 main jet won't do me any good if I can't get it to run right past 1/8 or 1/4 throttle.... Quote Link to comment Share on other sites More sharing options...
lowriderb Posted April 16, 2006 Report Share Posted April 16, 2006 are you running the stock head still? the first and last time i had my 4mm cub out with a stock head on it it was drinking water.. and blowing them out of 3 of the studs as well.. pulled the head off the head gasket is letting water passed (paint was missing from a water jacket to the combustion chamber.. also what have you done with the tors crap? if its a tors case then it wouldnt let you rev at idle though.. what kind of air filter set up are you running and do you think thats efficient? Quote Link to comment Share on other sites More sharing options...
Tim C Posted April 16, 2006 Report Share Posted April 16, 2006 I have a stock stroke cub ordered and hope to have them by the end of next week and I hope I don't have this trouble - I'll be running 30mm carbs w/dial-a-jets so adjusting the mains will be easy but I don't want problems down low either. Your slides in the carbs didn't get mixed up and put in backwards by any chance did they. When my CDI went bad it would rev out but it would idle fine - try swapping CDI's with a friend if you can - maybe problem isn't card related Quote Link to comment Share on other sites More sharing options...
dajogejr Posted April 16, 2006 Author Report Share Posted April 16, 2006 Hey...lowrider. Thanks for your help and input...I greatly appreciate it. NOSS head, bought new from Jeff with big bore domes and I THINK 18cc...it has 180PSI. I bought all new head studs, permatex'd each one...and I did have one leaking just a bit. As of right now, the head is off...and I'm going ot have Jeff get me some longer studs. 8 of the ten studs he sent me were short ones, 2 are perfect. I ended up stripping out 3 or 4 of the acorn nuts that come with the head, so I had to use the stock nuts in place. I thought I took my time and went over everything...Jeff took 45 minutes on the phone with me to over and explain everything in detail, I wrote it down..and followed his advice to a T. To answer your other questions. TORS have been gone since day 1. I have K&N Pods on the back, just cleaned, dried and oiled today...and not over oiled, either. Quote Link to comment Share on other sites More sharing options...
dajogejr Posted April 16, 2006 Author Report Share Posted April 16, 2006 (edited) I have a stock stroke cub ordered and hope to have them by the end of next week and I hope I don't have this trouble - I'll be running 30mm carbs w/dial-a-jets so adjusting the mains will be easy but I don't want problems down low either. Your slides in the carbs didn't get mixed up and put in backwards by any chance did they. When my CDI went bad it would rev out but it would idle fine - try swapping CDI's with a friend if you can - maybe problem isn't card related 503073[/snapback] Thanks...Tim. I'm positive the slides are right...cutout towards the back. I'm very very good with these carbs. I do have an extra CDI sitting on the bench at my house. I think I may try that next... Edited April 17, 2006 by dajogejr Quote Link to comment Share on other sites More sharing options...
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