1
TB Balance Tue Sep 27, 2016 10:57 am
Kafflut
Silver member
Well, I finally did. I adjusted them despite best advice. I've heard everything from "Don't touch" to "Never, ever turn on those screws, because if you do you 'll have to burn the bike and throw away your 8mm spanner just to make sure you don't try adjust them on the new bike you buy."
I can now say, with a degree of confidence, while "don't touch" isn't rubbish, "throw the whole lot away if ever you do fiddle with those screws" comes pretty close to being snake oil.
I did the valve clearance. I replaced the TB rubbers - not new, I made my own; more about that at some other time. I assembled the plenum & TBs, blocked off openings, put the whole assembly in water and introduced some air to check for leaks - just a little bit of pressure.
After final assembly in the bike and getting the motor running I followed the advice given somewhere else in this forum, I closed the brass bypass screws and got the TBs in balanced by adjusting the butterfly adjustment screws
It took about 20 minutes. No1 was way off and sucked all the water from adjacent bottles in a few seconds. Once I had No1 adjusted to a more reasonable level the rest was relatively easy. Not perfect but I fine tuned the balancing at idle by adjusting the bypass brass screws. Then revved the engine up to between 3000 & 4000 rpm. The levels in my 4 bottles remained at pretty much constant level.
I can now say, with a degree of confidence, while "don't touch" isn't rubbish, "throw the whole lot away if ever you do fiddle with those screws" comes pretty close to being snake oil.
I did the valve clearance. I replaced the TB rubbers - not new, I made my own; more about that at some other time. I assembled the plenum & TBs, blocked off openings, put the whole assembly in water and introduced some air to check for leaks - just a little bit of pressure.
After final assembly in the bike and getting the motor running I followed the advice given somewhere else in this forum, I closed the brass bypass screws and got the TBs in balanced by adjusting the butterfly adjustment screws
It took about 20 minutes. No1 was way off and sucked all the water from adjacent bottles in a few seconds. Once I had No1 adjusted to a more reasonable level the rest was relatively easy. Not perfect but I fine tuned the balancing at idle by adjusting the bypass brass screws. Then revved the engine up to between 3000 & 4000 rpm. The levels in my 4 bottles remained at pretty much constant level.
none of that there.