replaced everything and it still boils over every time.

[dubkatz]

Hey guys 87 banshee, last time motor was looked at was close to 10 years ago by a reputable(dune) shop previous owner had records of full rebuild.barely ever road it. I bought it a few months ago. First quad for me but not new to to smokers or bikes. Quad runs great, was bored .40 over has fmf pipes,k&n updated swing arm other than that stock with orig. shocks, radiator. etc. After a few rides and just getting used to it i realize its boiling over. So i ad coolant keeps boiling over put a total of 20'ish hours mostly trail one trip to the dunes. start looking into stuff. Long story shor. I have gone to a boss radiator, pro designs w/p, 1.1 bar cap, and it still boils over on just about anything other than idilng. I also ran the bike with the hose off and the pump flows water thru the motor just fine, so i doubt theres a clog anywhere. havent checked the jets, but plugs look good. idles fine screams as soon as it gets on the pipe. NOW heres the one thing that i can see is a problem but i cant see how it could be THE issue. Did a compression test and both cylinders top out at 75-80 psi. I know thats got to be fairly accurate because i can start the bike sitting down barefoot. It kicks over that easily. but it starts every time and screams. doesnt make any wierd noises no piston slap nothing. I wish i did a compression test right when i bought it because im thinking the constant over heating hurt it. I never ran it dry but it got low a few times. So now i dont want to do a top end until i get this overheating issue squared away. Im thinking about just doing a top end. and putting in some evans. that stuff will never boil over. but if there is something wrong thats just gonna mask it. any ideas obi-wan kenobi's of banshees, im dying here and cant think of anything else.

thanks,

[Phelps]

compression is too low and you may not be boiling water... you may be pushing compression past the head gasket/ O rings if it's a aftermarket head and causing it to shove water out of the radiator.

[So Cal Suspension]

compression is too low and you may not be boiling water... you may be pushing compression past the head gasket/ O rings if it's a aftermarket head and causing it to shove water out of the radiator.

This...

 

 

Or your jetting is so far off that you've been running it lean, and smoked the top end.

[dubkatz]

compression is too low and you may not be boiling water... you may be pushing compression past the head gasket/ O rings if it's a aftermarket head and causing it to shove water out of the radiator.

thaks for such a quick response, but im a little confused. when i come to a stop and shut it down i hear water boiling(or at least thats what it sounds like) and it will do that for prob close to a full minute. and everything is scalding hot if i pour water on the head(its stock) it sizzles off instantly. If it was compression leaking past the head gasket wouldnt it stop boiling within seconds or even instantly?

[Phelps]

sounds like there is a obstruction somewhere then...... take the topend off and send it to be bored and check the head for something blocking water from flowing. almost sounds like a air trap, but there is no real way for that to happen on a banshee.

[dubkatz]

This...

 

 

Or your jetting is so far off that you've been running it lean, and smoked the top end.

If it was that far off. wouldnt it starve for fuel way in the rpm's? and wouldnt the plugs looked burnt? The only reason i havent pulled one of the bowls and checked the jets is it still has the torrs boxes on top and it looks like i cant get the bowls off without pulling one of the carbs out totally. But im thinking ill need to do just so i know for sure.

[Phelps]

If it was that far off. wouldnt it starve for fuel way in the rpm's? and wouldnt the plugs looked burnt? The only reason i havent pulled one of the bowls and checked the jets is it still has the torrs boxes on top and it looks like i cant get the bowls off without pulling one of the carbs out totally. But im thinking ill need to do just so i know for sure.

yeah the first thing you needed to do was verify the jets are clean. the repair priority shouldn't be determined by how difficult the job is.

[dubkatz]

sounds like there is a obstruction somewhere then...... take the topend off and send it to be bored and check the head for something blocking water from flowing. almost sounds like a air trap, but there is no real way for that to happen on a banshee.

that was the only thing i was kinda thinking too but with the motor running even the stock pump would circulate the water as fast as i could pour it in the radiator. now obviously thats not under pressure, but i couldnt imagine it changing that much. and i burped the system every time i added coolant or replaced something. i guess im just gonna have to tear into this thing. arggg.....

[dubkatz]

the repair priority shouldn't be determined by how difficult the job is.

touché and thanks for all the help.

[dubkatz]

alright pulled one of the carbs. Bowl was spotless not a particle of dust in it. jets are crystal clean. main says 082 and pilot says 25. digital service manual says optional main jets are 200, 220 and 240. there is a little square symbol on both jets so i dont know if there mekuni jets or not.

after looking thru the manual. i cant imagine this main jet thats in there is on the same scale as 200+ main jets. would the bike even run with jets thats small much the less haul ass. this bike should have been jetted for sea level to 2k elevation. not mt everest.

Edited September 10, 2011 by dubkatz

[camatv]

i bet the main is a 280..

 

the book has jetting specs for a completely stock bike not a bike with aftermarket pipes on it.

 

are the fins on the radiator pluged? have you washed them out with a garden hose? also take out the 2 lil plugs on the sides of the juggs and drain all that i bet the cyls may have some bad coolant thats jelled or crudded up from it sitting all that time. you may have to yank the top end off and wash it out really good.

 

if it was only 80lbs of comp it probably wouldnt kick start anymore. after about 90 psi kicking they get really hard to start ..

[dubkatz]

i bet the main is a 280..

 

the book has jetting specs for a completely stock bike not a bike with aftermarket pipes on it.

 

are the fins on the radiator pluged? have you washed them out with a garden hose? also take out the 2 lil plugs on the sides of the juggs and drain all that i bet the cyls may have some bad coolant thats jelled or crudded up from it sitting all that time. you may have to yank the top end off and wash it out really good.

 

if it was only 80lbs of comp it probably wouldnt kick start anymore. after about 90 psi kicking they get really hard to start ..

wow i feel like an idiot the jet is def. a 280.

the radiator is brand new. Looks like i need to to start tearing sh!t apart. arggg.

man am i glad i got bikes to ride.

[Strm Trpr]

There is a plastic gear on the end of the WP impeller shaft.

They can melt and not function 100%.

And your low compression is probably due to a blown HG from a warped head.

Either way, I'd get yourself a Clymers Manual and take a look at it.

You can also eliminate the TORS as well.

 

Just my $.02.

 

One more thing, are those cold compression test numbers?

Edited September 11, 2011 by Strm Trpr

[rdzbangshee]

the water impeller is broke and cooked the top end or a bad crank seal good luck.

[Phelps]

did no one read any of his post? obviously if he changed the impeller he had the gear in his hand...