Tim Potteiger

What a great feeling it must be, now just to get mine fixed.....

Just to add to this, I would never impact the puller, it will almost always snap the puller. Tighten down with a wrench then tap lightly with a soft blow mallet. I have ruined quite a few pullers trying to impact them. I know they say not to bang on any part of the flywheel, but an impact rarely works.

I can do that, or if you are willing, I can even bring it out since I live in Prattville, you are just right down the highway 20 minutes. I have several sets of extra domes I can try out, Gary at K&N said the domes weren't damaged yet from detonation and looked okay, but who knows. They aren't that old either, since the last set peeled the o-ring groove off, I replaced them. Thanks David

Oh, sorry, yes Phillips B32 (111 octane) mixed 40:1 with Yamalube 2R. I finished up the re-assembly very carefully last night and took it out into the sand at the river tonight to test run it. Prior to previous times, the water leak/compression pushing the water back up through the radiator cap is already back. It usually goes for a good 2 - 3 days of riding hard before it starts doing it again, but not this time. I am at a total loss now. The water temp only got to 165 and yet i could hear it boiling and hissing in the motor and/or hoses. I have replaced the stock impeller with the pro design billet impeller, so I know the impeller isn't broken. I have a feeling it is pushing past the o-rings in the domes already again. Last time, I could clearly see where it had done this after the detonation issue had smoked the o-rings and they lost seal. I am going to test the water circulation first, but if that is ok, I guess my next course of action is to swap heads with one of my brother's bikes. One is Pro Design, one is Noss. If the problem moves to his bike, i guess it is safe to assume its the head. My Noss head now was new last spring and has about 3 hours of run time tops since I parked it all summer. I took the head over to my friends Machine shop and we checked to make sure it isn't warped. The cylinders measure the same and have the same base gaskets, so it isn't uneven cylinder height, nor warped cylinder tops. I cleaned up the cylinder tops thoroughly as well as previously stated. I am about to go set fire to it.....

Just for more info: are you running stock carbs and needles clipped in the middle ring? what pipes are those? did you have it ported or did it come ported or is it stock porting? how long did you own it while it was running before it died? did you change anything the trip before it died?

So now that this thread is 6 pages long and I am too lazy to look through everything again: you have spark right? you have fuel? you have air and combustion? Is it still backfiring? Can you summarize the problem and every action taken or test in 1 reply? I am with whoever said it is probably something simple that is just being over looked, and I am still betting on something electric: wire melted or separated, CDI, voltage regulator, stator, coil, etc

I went up to K&N and purchased some more copper washers so I can stack 2 on each nut, but where can I get these Parker Stat-O-Seals? Gary looked at my domes and o-rings from them and said detonation for sure, told me to back off the timing. I am going back to 2 to 3 degrees advance. I smoothed up the cylinder tops with some light grit paper on a flat block. I am going to re-assemble it tonight and go to a B9ES plug for a little cooler spark. Hopefully it will alleviate the issue. I am tired of working on it.

I would recommend you get a K&N stage 3 jet kit with the sharper taper needles and run a 270 main with FMF fatties. You set the needle clip on the middle ring with this needle from the kit. If you are sticking with the stock needles you do need larger jets (290 i think, but i wouldn't swear by it since I went to aftermarket needles), but I wouldn't move the needle. I ran that setup for a long time. That was the best tune for my bike before changing the carbs, porting, etc. And no, there is not break in time for heads and reeds. Just make sure and recheck the head torque after getting it hot and letting it cool off.

Must be the plastic then.....

Plug caps? I had a strange issue with mine running like crap at high RPM, turned out to be the plug caps.

Run to your car, fly down there as fast as you can and get your cylinders back, as others have posted, if he just "works on any engine that doesn't go in a car", I would never let him touch my motor. Port timing and duration on a banshee is crucial, at best you might just get back a motor that makes little to no more horsepower, and at worst, you might be buying new cylinders.

I have seen Cubs at +8, but I would stay at 4 personally.

I have re-surfaced the cylinders for that very reason, however I had wondered about the massive over bore and whether or not the domes might need to be different. I will look into that, thanks.

You can test the air leak theory (which sounds likely) very easily with a propane torch. Just turn on the gas and start "sniffing" around the intakes while idling. If the RPM comes up, you found it.

The only time I ever had a Banshee kick back and/or backfire was when one of the wires from the pick up had a slight melt in the insulation and it was jumping to ground on the case. When it did start, it backfired and ran like crap. I would seriously inspect the wiring harness inside the stator area for any burns. As to the crank question, stock banshee cranks are made of more than 20 pieces pressed together and doweled, and yes they can twist but usually only under extreme horsepower. banshee bottom ends are pretty damn though, so it isn't likely to be your problem. Engines need 3 things to run: spark, fuel and air (and obviously some compression to make those 3 work).

I have some leaking problems as well with my Noss head and before with my Pro Design as well. I not only have seen small amounts coming out around the studs, but I get compression back in my water jackets which of course causes it to puke the water out the cap overflow on the radiator. I have had this problem on and off with the engine since back when I was running the Pro Design cool head. The bike is currently .90 over stock bore, stock stroke and ported mildly for mostly pleasure riding. The old Pro Design head got too hot 1 too many times and finally cracked at the inner edge of the water jacket last year, so this year I replaced it with the Noss that did just fine until this last weekend, when the old problem of compression leaking into the water jackets started again. Upon removing the head I found traces of the o-rings from on the domes around the outside edge like the dome had lifted and pinched a little off and pushed it outside the groove and melted it to the cylinder top (the o-rings themselves are burned around the inner edge which indicate the dome lifted and they were exposed to combustion). I double checked the nuts before removal by setting my torque wrench to 21 ft-lbs and all the nuts measured 21ft-lbs except 2 that took about 1/8-1/16 of a turn before it clicked the wrench. I inspected the inside of the acorn nuts and I do see that most of the studs had bottomed out the acorn nuts and dug into the top. This was my original suspicion as well on the way home today. My theory is the bottomed out nuts were causing the added pressure to actually show 20ft-lbs torque, but had less due to the bottoming out, and after some run time, the domes finally started lifting enough to push compression back in to the water jackets. Is it possible that 18cc domes on stock height exhaust ports could be too much compression for 20ft-lbs of torque to hold down? The cranking compression as I recall is around 215 lbs. Has any one else had similar issues? I also back out spark plugs on occasion and reading here most are saying that is due to detonation. I have trouble believing that I am getting detonation. I am running 18cc domes, widened exhaust port but not raised, 4 1/2 degree advance timing, with Phillips B32 mixed 40:1 with Yamalube 2R, 36 Lectrons with 3-2 metering rod (which is actually too rich for my setup, it was recommended to run 3-1 metering rods) and .375 power jet, stock ignition and stator. I purposely run it rich for the time being thinking the water problems were starting from excessive heat due to lean fuel mixture.