BRASS AIR SCREWS

[twodogs]

Having just bought my 03 1150adv i have been servicing it and when i eventually came to balance the throttle body's the brass air screws are only backed out by cyl1 - half a turn and cyl 2 - quarter of a turn.

now i stand to be corrected here but my understanding was on the four valve engine the screws should be backed off by one and a half turns to start with and then adjusted from there to obtain a balance.

Since getting the bike it has been hesitating when giving it a good handful in top gear from mid range speeds, and i am wondering if this could be the cause of it.

I have done all valve and end float adjustments and the body's are balanced pretty well where they are but am wondering if this is making the bike too rich.

just to add that if you accelerate "normally" there is no noticeable problem.

your thoughts on this would be appreciated thanks Bob.

 

[twodogs]

Forgot to add that a mate of mine is betting that it's more likely to be a coil/plug cap but i ain't
convinced.

 

[Carl]

Forgot to add that a mate of mine is betting that it's more likely to be a coil/plug cap but i ain't
convinced.

If its a twinspark I would go with what your mate suggests... I had the same symptoms when one of mine failed.

 

[MOTOTECH]

The air bypass screws are for idle mixture.
It is almost certainly a coil problem.
Brian.

 

[Steptoe]

now i stand to be corrected here but my understanding was on the four valve engine the screws should be backed off by one and a half turns to start with and then adjusted from there to obtain a balance.

.

Thats just a guide, nothing more nothing less. Every bike is different.

Just get it in balance and the screws are wherever they are, don't fret over it.

 

[SecretSquirrel]

Thats just a guide, nothing more nothing less. Every bike is different.

Just get it in balance and the screws are wherever they are, don't fret over it.

I agree. I balanced mine at the weekend and found to get the slow running correct, the brass screws were only 1/2 turn LHS and 1/4 turn out RHS. Everything seemed well with the bike on a run into central London this morning.

Do as Steptoe suggests and don't fret

 

[twodogs]

Thanks for your replies on this, will have a look at the caps and leave the BBS where they are because as i say the bike is balanced and running sweet as it is so it's looking more and more like a coil. Bob