Throttle Body Balancing


I have just bought a Twinmax electronic carb balancer and have tried to balance my TB(Throttle Body's) three times but still the bike surges at between 2500-3000 revs (very annoying in traffic) Has anyone out there used a Twinmax? what revs should I adjust the cable..Has anyone had good results using a Twinmax?
The Twinmax should be used in 2 stages
a) at tickover when balance in achieved using the air screws only.
b) at higher revs 1500 -2000 when balance is achieved by using the cable adjuster knurled nuts- it is mega sensitive to cable tension.

If your bike is an 1100 then the throttle position sensor may also need to be adjusted using a digital voltmeter. I would prefer to adjust the TPS first and then follow on with the Twinmax. If you get a balanced reading (on the Twinmax) at say 2000 rpm then look at the TPS.

The BMW - micapeak pages by Rob Lentini provide an excellent write up on how to do it and why.

If you are still having difficulties then give me a call (just down the road in Redcar)

Dave Turnock
Moose, are you adjusting the cable setup on both throttle bodies at once.

Or are you adjusting the Right Hand throttle body to be in synchronisation with the left throttle body?

This could have a big bearing, as to getting it right or not!

The Left body is the one connected to the computer, the right body just has to be synchronised to the left one as it's only connection to the computer, is via one cable that twists the butterfly valve, hopefully in complete synchronisation with the left throttle body butterfly.

The downloadable PDF file at the heading of this section which is the manual, is worth downloading and printing out and reading in your most comfortable chair.

The information inside is excellent and the various ways different people describe the same thing (synchronising throttle bodies) is educational at the least and entertaining at it's best

Twinmax and damn good results


I used Twinmax 1st some 6000 miles ago. The results were AWESOME. Being my 1st bike I was kinda glad Mr BMW set it up a bit out. This gave me time to get to know the power of the bike (or so I thought). After Twinmaxing I was simply in awe of the difference, it felt like 5-10bhp. Not bad bearing in mind the idle was out slightly and the 3-4000 revs setting was not out by much either. So thank Mr BMW service man you may have saved my bacon.

Last Monday I did once more (6000 mile later) and this time RH idle get a tiny tiny tweak. The RH cable (the 3-4000rev bit) got a quarter turn at most. Got on bike. Rode like a complete nutter (safety was ensured at all times) and oh my goodness. It is a rocket. Vibration ? What vibration, smooth ? very smooth. Power, well POWER!!!! Getting to that red line gear after gear, it is so easy. Love it on over takes as it does pull a bit better up top and is so smooth. The last 200 odd miles have been great.

Oh I do like the twinmax, can you tell ? takes about 5 mins once you follow the system. The big trick as others have pointed out is to do the right side. Idle then I do 3,500 revs. I then check at 3000 and 4000 revs. Ever time you tweek the cable blip and blip and blip the throttle then check for 0 reading. And make sure you do after tightening the lock nut. The slightest change in length (including seating of the cable) does make a difference.
Sounds like more than 5 mins but if you just do little by little and repeat in a systematic way it is really quick and predictable.

Enough of this -- I'm off to add more miles.

All the best with Twinmax.
I am adjusting just the right hand side body. But when I adjust the cable for 2000-3000 revs, the idle reading on the twinmax seems to go out a touch. Now do I adjust the air screw againg to get the tickover right??
Yes, you should be balanced all the way from tickover upwards but you may find slight imbalance at higher revs
Dave Turnock

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