Throttle cable adjustments

Since my rebuild, my throttle has been erratic at the idle. I noticed that if I left a tiny bit of slop in the throttle, giving a bit of throttle the rpm would dip and then go back up, which tended to make it stall. What I have read it's a common problem with the slides being loose in the carbs. Anyhow, I adjusted the throttle cable by the handle so it didn't dip the rpm and now it idles just fine and comes off idle with no problems. Of course there is absolutely no slop in the throttle cable. Is this a solution, or just a temporary fix I have found? I have plans on getting the Amals sleeved by Lund this winter.

Dave
69S

G'day Dave,
I had exactly the same problem with my old Carbs and did the same with the cables after trying everything posible with the Air screw
to try and get a consistent idle. I think you're right in that as the cable pulls on the slide, it tips the slide enough to take up any slop
that was allowing extra air past it, thus enrichening the mixture a little. I believe mine idled better on a cold start than when it was hot.
I believe you have a temporary solution.
I now have pair of tighter carbs and the problem has gone.
Just be aware of the tight cables when turning the bars.
How does the price of brand new compare to resleeved.
AC.

I started it tonight and it was idling very nicely with the tight cable. Almost gave me some confidence that I could ride it and not worry about leaving my hand off the throttle. Not sure about the price of new carbs with anodized or chromed slides vs. sending them to Lunds for about $200. It may be a toss-up, maybe not.

Dave
69S

Hi guys, me again. I have looked in the shop manual and can't figure out how to adjust the idle on my 72 Combat with Amals. This is my first bike with these Amal Carbs so they are very strange to me. I tried to adjust the cable with the adjustment screw here on the cable, but it was already at the maximum. Is there any other way to adjust the idle? I am not certain how to even adjust it on the carb itself. Thanks!

Johnnymac said:

Hi guys, me again. I have looked in the shop manual and can't figure out how to adjust the idle on my 72 Combat with Amals. This is my first bike with these Amal Carbs so they are very strange to me. I tried to adjust the cable with the adjustment screw here on the cable, but it was already at the maximum. Is there any other way to adjust the idle? I am not certain how to even adjust it on the carb itself. Thanks!

Click to expand...

check out http://www.jba.bc.ca/Bushmans Carb Tuning.html lots of good info

Got it. Thanks!

As shown in the above photo my adjuster is at it's max as well, mid cable from twistgrip to junction box. What to do ? Order new cable or cut shorter and resolder nipple on, which I have never tried.

Torontonian said:

As shown in the above photo my adjuster is at it's max as well, mid cable from twistgrip to junction box.

Click to expand...

But what about the carb top adjusters?

'Choke' and 'throttle' lower cables are slightly different-so check you have the correct 'throttle' lower cables.

Hey Torontonian,
You should have similar adjusters on the top of each carby.
If they are also adjusted right out, then you will need a shorter cable.
Have a go at shortening the one you've got if you are confident that you can get the cable hot enough
but make sure that you have all the right gear, including some soldering fluid or acid to clean up the cable
before attempting to solder.
It was comman practice to make up cables once upon a time.
Once you have the cable battered up with solder, and you have slid the nipple along, frey the end of the cable
a bit so when the solder sets it becomes a bit of a birds nest. Then file it off neatly. I think it helps to stop
the cable from pulling through.
AC.

Most engines will not idle well until they have covered about 500 miles. When the cylinders still have the rough honed finish there is a lot of friction with the rings. Only once the engine is a bit broken in can you expect a nice idle.

You will find that an engine that is being re built after you put the barrels on it is hard to push the pistons down with your fingers. An engine that is just coming apart you can usually push the pistons down with one finger really easily, and maybe even get it going down fast enough so it will come back up and keep turning.

L.A.B., Aussie, was not aware after all these years that choke and throttle short cables had slightly differing lengths so will be inspecting this when Crazy comes up those stairs first snowfall. I have a bagfull of cables amassed over the years and they all got tossed into said bag. Obviously before attempting cable shortening and soldering .