Carb help please!!!

[beemer]

Iv'e reset my carbs as part of a full service!mixture and balance adjustment,i want to ask a question!!!when you rev the bike,how long should it take for the engine to settle back to it's tickover speed?i'm not sure,because i never took a note of it,but now the engine seems to take a bit longer to settle,so if i rev to say 4-5k it's slower to settle back to tickover,hope i'm making sense here!!!is it too lean?i did all adjustments per the BMW and Haynes manuals,and of course the great help on this site,thanks,J.

[weasel01]

i'm a total noob at this but spent the weekend fiddling around with it and found it takes some adjust go for a ride adjust go for a ride etc... till it stays put.

[Bob_Roller]

A common cause for the extended time to return to idle, is doing the carb adjustments on an engine that is not up to operating temperature .

Seeing as how you don't know if this was happening before you did your carb adjustments, a sticking  centrifugal advance mechanism in the 'bean can', that's the part that has the Hall effect sensor and advance mechanism under the front cover of the engine can cause a similar problem .

But personally, I would re-do your carb adjustments on a properly warmed up engine .

[beemer]

A common cause for the extended time to return to idle, is doing the carb adjustments on an engine that is not up to operating temperature .

Seeing as how you don't know if this was happening before you did your carb adjustments, a sticking  centrifugal advance mechanism in the 'bean can', that's the part that has the Hall effect sensor and advance mechanism under the front cover of the engine can cause a similar problem .

But personally, I would re-do your carb adjustments on a properly warmed up engine .

It was warmed up Bob,thanks,J.

[Bob_Roller]

An overly rich idle mixture can cause this too, the R65 owners manual states that after you get the mixture set to the highest rpm, that you are to turn the mixture screw in 1/4th turn .

I don't know if this will work or not !

[beemer]

An overly rich idle mixture can cause this too, the R65 owners manual states that after you get the mixture set to the highest rpm, that you are to turn the mixture screw in 1/4th turn .

I don't know if this will work or not !

Ive been playing around with it and nearly there,i just have a small amount of popping on one exhaust,does this mean it's to rich?

[montmil]

Confirm that your throttle cables have not be re-routed during the carb service work. I had a similar issue and corrected the cable runs.

Also, make sure your throttle stop screw -under the twist grip- is not dragging... Unless it's previously gone AWOL. Also, grips can rub on the throttle/switch block and/or have to much grease on the handlebar and throttle tube.

Monte

[Bob_Roller]

Usually popping from the exhaust is indicative of a rich mixture, the oxygen is already consumed by combustion, but there is still unburned fuel in there, and when it gets out to the exhaust system, it can explode when it finally gets enough oxygen to burn the remaining fuel  .

[beemer]

I will check these thing out!!and if all is well with the twistgrip,just check the mixture again,thanks for the help guys,J.

[weasel01]

Bob, when adjusting my carbs recently I found that when I started with the recommended 3/4 turn the bike idled well but if I went a 1/4 turn up or back the idle speed went down and the engine sounded poorly?
Should I have gone beyond 3/4 turn?

[Bob_Roller]

If your bike runs good to you, I wouldn't change a thing .

This may have been more of an exaust emissions concern, rather than an operating concern .

[montmil]

...I started with the recommended 3/4 turn the bike idled well but if I went a 1/4 turn up or back the idle speed went down and the engine sounded poorly? Should I have gone beyond 3/4 turn?

The air screw can be pretty sensitive to position and changes. Even the Snowbum mentions that in or out chenges of the air screw should probably be no more than the screwdriver's blade thickness. I'm guessing 1/16 turn either way off of the spec 3/4 turn out. That ain't much.

Monte

[weasel01]

In the how to section there is an article about carb sync and it recommends to unplug one sparkplug to set the max idle speed with the airmix screw of the oposite cylinder then switch. this doesnt apply to electronic ignition does it?.

[nhmaf]

The 'one cylinder at a time approach can be troublesome to the electronic ignition bikes unless you make sure that the plug wire is still connected to a grounded (to engine) spark plug.  I generally don't follow that approach.

The slight popping on exhaust, especially if revving up to higher revs ~6K and just letting loose of the throttle is often due to the action of the "pulse air" injection system - if you still have it on the bike, if the mixture is otherwise good.   My R65LS mixture (from exam of new plugs) is just about ideal, or maybe ever so slightly lean, and it will make some "pops" under this condition as it still has those darn snorkels (they should shut off under closed throttle, but don't always quickly enough -> extra shot of air into exhaust stream under trailing throttle yields light popping/crackling - helps me to keep up with the H-D crowd, though!
;-)

[beemer]

The bike seems fine now,after going throught the balancing act a few times,it just takes time to get it correct,as mentioned,1/16 makes a hell of a difference to the way it runs,all the popping has gone now,and she runs very smooth at 1050rpm(65LS)thanks for all the advice,the throttle cables are all fine with no binding,i used my ears this time,(being a musician,it was tuned to B, ,)Thanks,guys,Julian.