2 problems............possibly

[MR.E]

Now then

1, i was servicing the carbs, the o'rings on the butterfly arm needed replacing, first carb went well, second one posed a little problem.
One of the little screws that holds the plate to the arm, in the carb, stripped it's head & i can't get it out & in frustration i stripped the other thread on the screw next to it!!
Now i've a screw that won't come out & one thats 'carefully placed' & to top it off STILL got a leaking o'ring!!!

2, which i think is the real error!
I took the headers to a bike 'customisers' wanted to know about getting them polished/ cleaned up etc.
Whilst they had them, dont know have they got it passed me things are still pretty sh!t home so probably wasn't listening, they chopped off the 2 pipes that join the headers together (balance pipes??), which now means the headers are 2 separate units.

What will this do to the running of the bike, if anything??

Thanks

[Bob_Roller]

Your first issue, I had the same problem, with the screws .

 I drilled the srews out and replaced the throttle shaft, it wasn't costly, less than $20US .

You probably won't notice much of a difference with the cross over pipes removed .

From what I can remember, most twin cylinder bikes don't have crossover pipes .

[Barry]

1. A new shaft and screws will only cost you £11.00 from Motobins.

2. In theory the crossover tubes allow the exhaust gases from one cylinder to pass through both exhaust pipes which therefore represents a lower back pressure which is said to boost low to mid range torque. Why does it boost low to mid range only ?  Because at high revs the exhaust gas pulses are traveling too fast to take enough advantage of the alternative route.

That's the theory. In practice the advantages might only be noticed on dyno.  The first crossover pipe I remember is my mid 70's Triumph Bonnie. I don't recall Jap twins having them at the time perhaps because there was less advantage due to the 180 deg cranks and uneven firing impulses.  

[tvrla]

+2 - new shaft, and the balance pipe, in my experience, only softens the exhaust note. It'll be a little more emphatic now - I like it that way.

[Lucky_Lou]

you could replace the butterfly arm screws with some M3 stainless steel screws with nyloc nuts at a push but better to replace them, the 79 model only has 1 crossover pipe later models have 2 so BMW must have had a good reason for the "improvement" suggesting the balance pipes are important.
Lou

[tvrla]

I'd like to see before and after dyno charts for that mod.

I have talked to a professional exhaust designer/engineer and his opinion is that the balance pipe is for sound reduction only.

[bruce_launceston]

My R65LS has been running very well with a 2 into 2 system and no balance pipes for well over 20 years.
If there was some change it's not enough to be noticable.

AND its so easy to get the headers and mufflers off!