Balancing twin rotor idle models

[TonyP]

Hi All

I'd like a bit of guidance on setting idle and balancing the carbs on my air cooled model. There are two nipples/adaptors to connect a manometer to, however one of the nipples has a cap on it, it looks like someone has adhered it in place. How easy is it to take out the adaptor, will I need to remove the plate that surrounds it. If I do how does it come away I see it has a pin but I can't see how it comes off.

Regards

Tony

[wust588]

Tony, I presume you mean the 2 brass adaptors, one on the top of each housing?
If so, they are just screwed in place, with a normal right hand thread, 12 or 13mm AF as I remember.

When you say plate, do you mean the steel one on the RH side, and plastic on the other side? If so remove.

[TonyP]

Thanks for the reply, yes brass adaptors, came out ok, removed the little plug and replaced all ready to play with a manometer.
The plate retains the throttle butterfly cable.

[TonyP]

The manometer did not work! The suction on the right was so much higher it just sucked the kerosene straight up the tube.
Could not be balanced with the idle screws, any advice please. c

[johnbirchjar]

On the odd occasion that I have had to "play" with the settings on my Classic I got the bike to running temp;screwed the idle screws all the way in,then screwed them out two and a half turns each,then listened to the engine revs as I tweaked each side,the mixture screws are a lot harder to tune ,lots of miles by trial and error,a bit old fashioned but it works for me, (The bike averages 45MPG regularly and the exhaust pipes are that lovely pale grey colour after a long fast ride on motorways )Happy tuning,ride safe,J.B.

[TonyP]

Hi John

Thanks for the advice, I have adjusted the idle screws as you described, definite improvement but still not 100%, I evedently would not make a piano tuner.

Tony

[johnbirchjar]

What are your bikes symptoms?J.B.

[TonyP]

JB

Latest, I took the carbs off and resealed the air intake connection to the frame. Not sure it improved much I still have an unbalanced tick over. Have not been able to ride due to flat battery, when charged it was heavy rail, so no riding, not that I'm a fine weather rider but I don't like cleaning bikes. Will hopefully get out Friday to see how she runs.

[johnbirchjar]

When I first started riding the Classic(many thousands of miles ago)the Idle Rod was set up all wrong and was an absolute pig to ride when the engine was cold and the idle was all over the place ,and because I was a "Rotary Virgin" it took me simply ages to figure out what the problem was ('cos the owners handbook warned against altering it)
This is not a five minute job trying to sort this out 'cos one has to alter the setting when the engine is cold,(trying to do it with a hot engine gets you BURNT FINGERS (A little tip ,before taking off the little spring clip STUFF SOME RAG UNDER IT to catch it 'cos it's a racing certainty that you will drop it either while taking it off or when putting it back on,and it drops down onto the exhaust manifold and is almost imposible to retrieve,even with one of those retrieving tools)Then ride the bike around for a bit to settle the carbs and get the engine nice and warm and assess the result,if not what you think it should run like, wait for the engine to and alter the rod,and so it goes on,I expect there is a simpler way to do this if one has the proper equipment, but like tuning the carbs,it how I have learnt to do it,good luck,J.B.

[TonyP]

John
This sounds like a very likely candidate. When the carbs were refurbished the cam plate which the rod is connected to was replaced so it is very possible that the fixing point has changed and hence the idle rod distance. Did not realise it would have the effect experienced by you, it sounds very much like my problem. My rod is missing the lock nut as well!
The workshop manual simply says adjust the idle rod to keep rpm below 3000 when cold and choke fully out.
Regards Tony

[johnbirchjar]

Hi Tony,another thing you may want to check is the pipe that bends round the chrome inlet pipe from the carbs to the chamber,make sure they are well pushed home('cos if they are not, air can be sucked in around them and upset the ballance,)J.B.

[Interpol2471]

I have spare rods and nuts etc also check o rings on idle by pass pipes

[GeoffD]

Regarding dropping the reataining clip. If you tie a piece of thin/strong thread (I found dental floss to be ideal) around the narrow part of the clip & tie the other end to the clutch cable, then if you do drop the clip, it can be easily fished out again without burning your fingers. You can easily cut the floss away afterwards, or just leave it in place till next time.