creamsickle

so I took the head off and found that there was some greyish yellow buildup on my pistons the left was worse then the right. I can scrape it off with my fingernail. not realyl sure but I think its from a coolant leak so im going to change out the orings and clean off the pistons a little and give it a shot. anybody have any advice on how to clean then off. http://i15.photobucket.com/albums/a390/kcpoager/6357a415.jpg

yeah the whole yellow thing is really gettin me messed up here. if anybody has any knowledge of this please help. yeah it kinda seems like my bike has the same problem as yours.

I already did a leak down test and it checked out. a leak down test wont test the inner oring so I will still ahve to look and see if its gone bad. the bike makes great low end power. it dynoed at 52ft lbs of torque at like 6500 rpms. im running the paul turner pipes. my problem is that I cant get it jetting right cause of this weird ass yellow plug. I had a builder deck it and assemble and cut the domes so it should be all up to specs. but I will have to see. im goign to throw the thinker base gasget on to bring up the port timing again and then see how it runs. I really dont want to go get new domes and get them cut but if it is the head clearance thats my problem well then I guess I dont really have a chance.

ok so im running a 4mill cub with 35pwks and a noss coolhead with 18cc domes. the timing is advanced 5 degrees, the cylinders have been decked on the bottom in order to make it more of a dune bike, and for some reason it really hasnt been running good. I did a compression check and both cylinders were at 175psi did a leak down a little while ago and it checked out. I am runing c12 race gas and using the torco gp7 oil. when I checked the plugs the left cylinder seemed to be running leaner then the right and the plugs were both yellow. the left was like canary yellow, weird coloring. never seen a yellow plug. I am running engine ice and am wondering if that could be leaking in and causing it to become yellow rather then carmel. my jetting is 52 piot and 162 on the main. before you get into the power it has a bog. like all banshees but the bog is kinda funky, almost like the main is way too big. but just a slight bit different, more choppy then a fat main. but the plugs look like they are lean I cant figure out what the problem is. anybody have any ideas? I will probably be pulling the cylinders to check the gasgets and will be throwing in a thinker base gasget to bring it back to the normal cub port timing.

yeah the leak down test is at 6psi but they say that normal leak of 1psi per minute is acceptable. when the biek started to rev did you look to see if both cylinders were firing. sometimes it seems likeboth are but really one side is firing and the other is jjust pushing air out the pipe cause of the compression stroke. definatly do a leak down test and also a compression test then let us know if they check out. what is the timing on the bike?

the +4 or +7 is in regards to the length of the stroke over the stock. basically its just a longer stroke. 4mm or 7mm longer then stock. there are usually two rod setups. the long rod which is 115mm long or the 110mm rods. which is why some people say they have a 5mill rather then a 4mill. its cuase they are using a 4mill crank with 115mm rods. the longer the crank the more swept volume. and on a scavenging two stroke motor the more the better(for high rpm power output). you will need to check the degree of your ports to see if you can do a stroker crank. I am assuming you have a play port so you should be fine, but if the exhaust port is too high then, well you are kinda out of luck. you will have to get some custom cut domes though, if you want to get a stroker crank. usually its easier to get the stroked crank done then after that get the port to match, rather then the other way around. and if you go to anything bigger then a 4mill crank you are going to need to get the cases trenched out so that you can accomodate for the larger stroke.

can you pinpoint where the noise is coming from? are you suer its the kickstarted. you listed a few different places of chatter. could be the bushing on the basket or an off balanced crank? do you have any specifics?

honestly shaving down a flywheel really doesnt do much. its not that much weight that is noticable. some may argue that spinning mass is spinning mass. but really I find it hard to notice the difference in revs.

dont change the jetting. if it ran good before there is no reason why jetting would have to be changed. try switching the plug caps. start small then work up to the bigger things. make sure it has spark. clean off the top of the plugs so that they have a good connection. not really sure what you mean by it running like crap but make sure you take off the reeds and look for cracks chips or gaps in the peddles.

the bushing on your clutch basket could be going out. I know they make that noise like when you described. it also can make that chatter when its at real low rpms like almost about to die. if you dont have steel bushings yet I insist you get them.

well doing it hot wont do me any good right now cause the right side isnt firing haha. but I guess I can warm up the left sylinder haha. so you say throttle open even when its off? like when you are kicking it over with the ignition off?

so my sisters shee is stock except for like reeds pipes and a filter. we ride at sea level. I took the compression and its like at 105 for each cylinder. Ihave no idea what stock compresion is. never owned a stock shee haha.

its a real nice lookin bike man but you are selling to a small crowd. its more of a drag bike, you would have better luck parting it out. I know I would be interested in the engine. its a nice setup. did you try posting on planet sand yet?

I use bel ray 80wt. I have also used the torco 80 before. both work great.

the only way you are going to drain the bowl is if you are running alky. you wont need the bigger bowls.

no gearing shoudl not affect the clutch. I run 14 44 and it runs great. I also went to a billit basket. you may of had your clutch cushions go out or the idler gear bushing went out and it slipped and chowed your basket. I have a used stock basket without gears if you want it. like 45bucks shipped.

ouch those done look too good. what compression are you running or were you running and what kind of gas. looks like a detonation at its prime.

dont run stock carbs. when you are running too small of carbs it can work and you will lose hp but yo can also burn up your engine because they will not be consistant. dont take the chance wait till you get bigger carbs. what size crank you running. I have some 33pwks if you are interested. 225 shipped.

eddy sanders racing has an inline temp guage for like 70 bucks. it looks cool is works good. I have one on my shee and love the convienance of knowing the temp of my engine at a glance.

aight well I have soem good parts that I have to get rid of. I have a stock stroek trued and welded crank that came out when Iwent to a stroker motor a month ago. its in awesom shape bearings are still good. $160 also have 33pwk carbs with slides caps needles and jets.$225 shipped havea stock radiator that in great shape no huge dings or cracks.$100 stock clutch basket without gears. make offer and a stock impeller make offer. also have a buddy who is selling his paul turner mid ranged pipes chromed in good shape with fat bor silencers just repacked. not sure what he wants for those. pm me and I can get a price. I dont have any pics right now cause my camera is broken. but I assure you all parts are in working condition, no tricks

I havea had that problem a few times. I know afew signs of boggin rigth off idle are A) a pluged pilot jet or bad reeds. I would check the intake tract to make sure that everything is working properly. no gaps in the reeds and no sticking in the reeds. make sure both jets are clear. what engine setup are you running. carbs, reeds, cylinder, compression, elevation. so on and so forth. you still have a tors? and are both sides firing the same? usually if the main is too rich you wont feel it on the bottom end. and if the pilot is too lean it will bog.

if you are dirt riding I dont care what you do to your banshee, you wont keep up with the 450 dirt bikes. ive got both, a cub and a dirt bike and always will walk away from my 421 cub with my dirt bike. unless im in the sand. my cub is a decked 421 with 35pwks and 18cc domes on race gas and running paul turner mid ranged pipes. its a low end monster. doesnt top out very fast but it has so much torque(51ft lbs) at such a low rpm (6500). its an awesom dune bike. cubs are nice becuase they can be detuned in order to make them a play bike but if you want the arm ripping pwoer changed the pipes and carbs and you will be good to go. I vote for the cub. assuming you wont get a dirt bike for the dirt.

your carbs are way too small. I didnt think there was a 68mm cheetah. I thought they were 73mm. I bet if you go to some duel 38s or even 35s you will gain a good 10 to 15 hp. and new pipes will give you another 10 I bet.

I run a 421 cub on gas(110) with paul turner pipes(midranged) 35mm pwks vforce 2's, noss coolhead with 18cc domes. the cylinders are decked 40 thousanths. no lockup on it so it runs like 76hp on the dyno. slips a little but a dyno will make a clutch slip unles its a lockup becuase it hooks up so hard. so I could probably get a few more ponies out of it with a lockup on the dyno. I changed out some parts with cam at redline racing and with cpi inframes and larger carbs it was right around 90. a dyna might kick it up a few more if the curve is set right. a little more fine tuning it will get to the mid 90s. if you go to alky it will break 100. but right now my bike is making 76hp with 51ft lbs of torque at like 6500rpm. it drops off before 8000. the cpis reved to 11,200 rpms. my power kicks on a little before 4,000 rpms. so the power starts real early. Like 2.5 seconds early. which is why its my dune bike

sounds like a lean main jet. plug chops arent always accurate. what size are you running in the carb. check the float bowl level. I doubt you are sucking the carb low but still always good to check. what is the timing?