- Location
- NJ
Like alot of older ski's picked this up for free , needed a lil love . While re shaping the foot tray noticed a 14" long crack under the seem on the left side so perfect time to add some tubbies after layering up some glass . 
300/440/550 1990 550 piston port
- Thread starter kankleGnar
- Start date
- Location
- NJ
final shaping complete just some finishing work before turfing
- Location
- NJ
ski is so much fun to ride now , especially not filling up with water . I think the tray ended up being close to 2" wider per side witch makes foot placement much more comfortable . Only other mods considering would be reed motor , my ski rips but its very moody, one day it will start and idle fine then next day will start fine and die a bunch times before pulling me out off water
Last edited:
hillbilly550
Rich L
- Location
- Lewis Center oHIo
Nice job. The wider tray has to be nice. I love the 80s neon colors. If you haven't rebuilt the carb I would start there on the drivability issue. Also make sure there is no water in the tank.
- Location
- NJ
found problem to be the primer was shot , so while i was in there replaced most of the fuel lines . only got an hour on it this weekend but started and ran great so fingers crossed .
- Location
- NJ
toasted the bottom end last weekend so now time to rebuild the motor
- Location
- Texas
looks good!
N2 H2O
Previously Tbone550
- Location
- Charlotte, NC
Thats it's way of telling you it wants a 650...
- Location
- NJ
- Location
- NJ
front lower rod bearing toasted , flat rollers and no cage . Also my impatience getting the 650 coupling off
iangdesign
Cats, lots of cats!
- Location
- United States
Lucky coupler...I took 3 teeth off when I was building mine!
- Location
- NJ
custom throttle bracket, from blaster , lil cut and weld to get it just right . a tight fit for sure cant wait to test it out
- Location
- NJ
after trying to get my BN44 from my 550 to work ,couldn't make it fat enough , I just raided my friends blaster parts pile and got an SBN44 that was taper bored , hopefully can get it running descent this weekend
the WaTeRhAwK
fryin' up a/m electrics..
- Location
- okc
what initial settings did you use, and what was your pop off pressure set at on the regular BN?
- Location
- NJ
not sure of pop off , but theres no jets on the BN just fuel screws , even with high and low turned all the way out i could ride it but anything more than half throttle would start starving for fuel , and this was a couple hour process of half turn at a time
then after some research , everything i read just said to ditch the BN and jet the real deal SBN
the WaTeRhAwK
fryin' up a/m electrics..
- Location
- okc
Did you have an .030 restrictor pill in the return line?
Regular BN carburetors work just fine if they're set up correctly. Most of what you hear and/or read on these forums and the net about them being "junk" is from lack of experience from the user. The regular BN carburetor was designed by Mikuni specifically to be used on the 550, with the mechanical rev limiter. If the rev limiter is bypassed or removed, an .030 sized restrictor "pill" has to be installed into the return line going to the tank, or the carb body will not hold fuel in ample volume long enough for it to reach the bomb sight of the carb. i/e, the fuel will run straight through the carb body and back in the tank.
Also, the initial settings for that carb are as follows:
High speed: 15/16ths of a turn out from closed.
Low speed: 1 and 1/8th out from closed.
Pilot: 1 and 5/16ths out from closed.
pop off should be around 17 psi with most a/m flame arrestors.
Stock flame arrestors are most generally restrictive to airflow, so they created super high manifold pressures, so the carbs are set up from the factory with a high pop off, usually around 24, and I've even seen them as high as 30 psi. If your intake filter setup isn't restrictive like a stock setup, and the pop off is set too high, this could also starve it of fuel.
That, coupled with the absence of the the rev limiter and no restrictor in the return line will definitely cause the problem you described, as either one alone would cause it to exhibit the same issue.
I've used regular BN carbs on 550's for 25+ years and have never had anywhere even close to the problems with them that I've read about on these forums.
Regular BN carburetors work just fine if they're set up correctly. Most of what you hear and/or read on these forums and the net about them being "junk" is from lack of experience from the user. The regular BN carburetor was designed by Mikuni specifically to be used on the 550, with the mechanical rev limiter. If the rev limiter is bypassed or removed, an .030 sized restrictor "pill" has to be installed into the return line going to the tank, or the carb body will not hold fuel in ample volume long enough for it to reach the bomb sight of the carb. i/e, the fuel will run straight through the carb body and back in the tank.
Also, the initial settings for that carb are as follows:
High speed: 15/16ths of a turn out from closed.
Low speed: 1 and 1/8th out from closed.
Pilot: 1 and 5/16ths out from closed.
pop off should be around 17 psi with most a/m flame arrestors.
Stock flame arrestors are most generally restrictive to airflow, so they created super high manifold pressures, so the carbs are set up from the factory with a high pop off, usually around 24, and I've even seen them as high as 30 psi. If your intake filter setup isn't restrictive like a stock setup, and the pop off is set too high, this could also starve it of fuel.
That, coupled with the absence of the the rev limiter and no restrictor in the return line will definitely cause the problem you described, as either one alone would cause it to exhibit the same issue.
I've used regular BN carbs on 550's for 25+ years and have never had anywhere even close to the problems with them that I've read about on these forums.
- Location
- Charlotte, NC
the sbn is just a much better carb soo people get rid of the bn for that very reason
- Location
- NJ
never had a prob with the BN on my 550 , and yes i restricted the return line but no matter how we tuned it it would not pull hard all the way through ( this is on the 650 motor ) it was just to lean and the fuel screws were at there limit meaning one more turn they would come right out .
- Location
- NJ
I've used regular BN carbs on 550's for 25+ years and have never had anywhere even close to the problems with them that I've read about on these forums.[/QUOTE]
not sure if you noticed im running 650 motor and electronics from x-2 i believe , never had a prob with that carb on my 550
not sure if you noticed im running 650 motor and electronics from x-2 i believe , never had a prob with that carb on my 550