maskmanLS6

you will need some port work and better intake , fuel delivery ,and exhaust to keep you running up front, especially if theres a big bore can am to compete with. research several options before you start spending money because there is tons of stuff out there for a banshee build. i just built a 60 hp trail machine and was amazed with the amount of after market parts and machining available for banshees. Ill be glad to give you any advice and knowledge i have to help out with your build. Im not a pro but after building mine i have some trial and error advice to pass on.

I just went through the same thing and the problem was in the pilot jet passage way. remove the pilot jet and take some carb cleaner and spray through the pilot passage way. Keep spraying until you get the cleaner coming through both exits into the carb barrel. If you look closely you can see a tiny slanted passage going towards and joining the main pilot passage. There should be cleaner coming out both exits when there clean. Youll need a small straight blade screw driver to get the pilot jet out. After your finished with the passages spray through the pilot jet until you can see through the hole and it looks perfectly round and open. Check your needle clip positions also as well as clean the main jets and passages. The jets are only part of the path to the carb barrel, if the passages above them is restricted then you will have that problem. Im pretty certain that will cure your problem.

I just had a similar problem and it turned out to be my flywheel. I couldnt understand how it worked for a few minutes and then stopped working. I didnt think there was anything that could change in a flywheel but evidently i was wrong. I changed the flywheel and the problem went away. Electrical problems are the hardest to diagnose unless you know the basics about the system and how it works. Also knowing the details such as ohms and current requirements really help.

New orleans is in a giant bowl of mud surrounded by levees and sea walls though. Might be a little below sea level.

I think its right around sea level, I live in biloxi ms. two blocks from the beach.

I took the bike to the spillway in new orleans today and rode for about 4 hours with the stock unshaved head and the timing pulled back to 4 degrees. It ran better than i thought it would and didnt have any detonation issues. I did a compression test and it pumped up 140 psi in both cylinders which seemed odd to me because i thought with a stock stroke and head it should be around 120 or so. Does any body know what the compression should be with stock deminsions? Could my base gaskets be too thin or something? Im not worried about it but it just doesnt seem right to have 140 psi with stock stroke and head.

Yea i just went through that with a head that was milled .040 . I was getting detonation on the top end with pump gas. I was lucky and didnt get any damage before i changed it out with a stock head. Im gonna send this head to mull engineering when i get the extra cash.

Yea i just went through that with a head that was milled .040 . I was getting detonation on the top end with pump gas. I was lucky and didnt get any damage before i changed it out with a stock head. Im gonna send this head to mull engineering when i get the extra cash.

My cylinders are stock with an aggressive trail port job. The port work is shy of a drag port but more than a mild trail port. Advance machine shop in Pa. did the port work and bored the cylinders to 65 mm . I used weisco pro lite pistons with a stock stroke Vitos crank. Im running the stock carbs with .30 pilots and 340 mains . I have K&N filters and FMF gold series exhaust . My jetting is pretty close because my plugs look good and it transitions from the bottom end to the power band smooth and without hesitation. I put a stock head back on it this evening and it runs great but i can feel some loss on the bottom end. The loss isnt enough to be worth the worries of having to little of squish height and always being paranoid about piston to head issues. Im gonna send this stock head to mull engineering when i get the extra cash and get a good set of domes cut in it and have them shave it to specs to keep me in pump gas territory.

Thats my plan. Ill call them monday and ask them which one they want to work with and send it to them. Ide rather have a stock head worked without the O rings and studs that the cool head requires. I dont plan on changing it out after its together this time. Plus the work they will do will be cheaper too. I pulled the shaved head off today and without doing a squish test it was obvious that the squish is too tight. The detonation on top end was also an indication and after pulling it off im glad that i got the advice here that convinced me to change it out.

I dont plan to run out and buy a cool head with domes if i get the stock head machined. Im just lookin to set it up once and be done but i dont have alot to spend. Im probably gonna send a stock head to mull eng. and have it done and run it from now on.

I dont plan to run out and buy a cool head with domes if i get the stock head machined. Im just lookin to set it up once and be done but i dont have alot to spend. Im probably gonna send a stock head to mull eng. and have it done and run it from now on.

I take it that you would just get an aftermarket head and domes then scrap the shaved head?

I plan to throw the other stock head on it for now and send the shaved head to get the domes cut for propper squish if it can be done cheap enough. I dont want to tie up much cash in the head because ide just replace it with a cool head and domes first. Ill see tomorrow where my squish height is at and get back with the numbers so every one will know for sure if .040 is too much to remove from the stock head.

I plan to do that when i have the funds available, right now the stock head is my only option. I would much rather have the cool head and domes but its not in my budget right now.

Thanks for the advice guys. Im going to do a squish test sunday and will pull the timing back to 4 degrees . I have another stock head i can throw on it if the squish test is too scary. Im gonna allow .035 squish minimum and im gonna mix a 50/50 race and pump gas mix and go from there.

I was afraid it would be too tight. Ill do a squish test to be sure before i pull the head. I thought the stock squish height was around .080 but im probably wrong. I hope it hasnt damaged my pistons yet. Ive only put about 1 1/2 hours on the engine so far and only wound it up twice. Thats when the detonation occured on the top end and i havent ran it since.

Is the cc size of the domes the same cc units used to measure liquid?? If so i can just use a measuring flask to test the dome area. And how much timing can pump gas handle??

What conversion do i use to determine cc volume of the domes? liquid im sure but i dont know the conversion formula. As far as the squish test goes i plan on doing one sunday after i get the caliper to do it. I didnt have all the tools needed to work out all the details when i put it together.

Looking at the unshaved stock head that i have the squish area has been milled down to the max on the head im running. .040 is probably the max amount to shave before having to cut another squish ring into the domes. I hope this is the case and i dont have piston to head contact issues. The factory squish height is around .080 from what i understand so .040 should leave around .040 to work with and that is enough according to what ive read and been told. Is this correct??

Yea i figured it was gonna be close when i was buildidg it. I wasnt sure what the compression was gonna be after the head was milled but i was hoping i could get by with pump gas. 50/50 wont be that bad though as i dont get to ride too often, maybe twice per month. Im hoping that the octane solves the pinging on the top end.

my compression numbers are 166 to 169 on both sides. My squish area has me a little concerned but the head wasnt shaved passed the original squish ring.

Im running a stock head thats shaved .040 and im getting some detonation on top end. Im running ported cylinders and 5 degrees timing with 340 mains in stock carbs also. Will a 50/50 race fuel and pump gas mix be ok?

How much can be safely removed from the stock head before additional machine work is necessary?