What Did You Do With Your Commando Today?

Starvingphotog said:
Hey there Dave. I'm curious about your tune up of the carbs in a little more detail. Seems there is the published routine and most people have their own routine. I don't have a routine and know that my carbs are not in tune, let alone synchronized, at the moment. I would like to work on that this summer. So, wondering if you would share your routine and tools with me, privately or to the whole group. I'd be doing this to my 850 that I currently ride. The 750 Combat is still in the house, being decoration:)
Click to expand...
So here goes.

1 warm the bike up properly
2 check for air leaks - with the bike on idle spray some brake cleaner around the manifold to head and carb to manifold joins - if the idle changes you have a leak, fix this before you go any further
3 set the mixture screws - turn them out, I start at about one full turn out which should be a bit rich, until the tickover starts to slow down then turn them in about a 1/4 turn then repeat on the other carb. I repeat this process at least a couple of times.
4 check the throttle slides are synchronised - I use a couple of wooden coffee stirrers tucked under the rear of the throttle slides then open the throttle and watch them move, they should move in unison, if they don’t adjust the cables until they do
5 finally I set the idle, I’d do this one at a time by removing a plug lead then start the bike on one pot and adjust the running side to 1,000 rpm then repeat on the other side. I then start the bike with both caps on, the idle will be high and I reduce it by turning each idle screw by the same amount until I get a tickover of around 1,000 rpm
6 now I whack the vacuum gauges on and check that I’m getting the same vacuum at idle, usually it’s pretty close after the above, and I then fine tune with small adjustments to the idle screws until they’re pulling the same vacuum. I then double check the throttle slides are in sync by opening the throttle (if they’re out by much the gauges will move in opposite directions as you blip the throttle) again I’ll tweak until they’re bang on

You can do all of this with vacuum gauges but I find it to much of a faff and prefer to get there manually before fine tuning with the gauges.

This is just the way I go about it and it works for me however others will I’m sure have different opinions.

Dave
 
Rode into work today. I never go in to the office much anymore, but we decided to get a few people in together for a change of pace.

Too damn hot with jeans and a cotton jumper underneath the Klim. I usually wear shorts, but was running late so just got dressed and over dressed...

Nice to split traffic tho.
 
Broke my tacho cable this afternoon. I had tried to re-route, to run it inside the headlamp mount. Even moved the tacho up against the mk3 light console, to give a slightly straighter run. But it wasn't straight enough. The needle started wavering and died. It was a new cable, freshly greased. Ordered a new cable and have moved the guage back out. Hopefully, no other damage done.
 
ashman said:
Been over 8 years since I rode to work, thank you for giving me a redundancy at 55 was the best thing to happen to me and able to live on my super pension, more to life than working for the man.
Click to expand...
I kinda regret not staying where I was a couple years ago, working half time consulting and half time at home on the land. But that gig grew into full time, and is too hard for old guys like me (58) to find good work - they want all the young uns who arent so bitter and twisted. :rolleyes:
 
ashman said:
Been over 8 years since I rode to work, thank you for giving me a redundancy at 55 was the best thing to happen to me and able to live on my super pension, more to life than working for the man.
Click to expand...
I'd love to retire I've got no pension worth anything
I'll have to work until I'm 67 another 5 years to claim the state pension
Oh well
 
Yes Baz I have another 5 years to go to get the old age pension at 67 and working at a Gov run Tec College (TAFE) for 31 years we had a good Gov Super, I was planning on early retirement at 56 as I could get my super at 55 but the Gov at the time offered redundancies so I jumped at it and got a good pay out and now living on my self funded super pension, I own everything and draw enough money to live each forenight and pay all the bills, I am not rich but have enough to live and support my wife the kids have left home and I still have all my toys to play with and we still have redundancy money put away, life couldn't be any better and I still haven't done all the things I said I would once I retired, covid has slowed us down but I have done a full reno inside my house and the outside is next but that's just a lick of paint so easy job and I can take the bikes out or go bush when ever I want at anytime, there was no plan with me on working till I dropped, life is to short for that, enjoy it while you still can I recon.

Ashley
 
Dellis said:
So here goes.

1 warm the bike up properly
2 check for air leaks - with the bike on idle spray some brake cleaner around the manifold to head and carb to manifold joins - if the idle changes you have a leak, fix this before you go any further
3 set the mixture screws - turn them out, I start at about one full turn out which should be a bit rich, until the tickover starts to slow down then turn them in about a 1/4 turn then repeat on the other carb. I repeat this process at least a couple of times.
4 check the throttle slides are synchronised - I use a couple of wooden coffee stirrers tucked under the rear of the throttle slides then open the throttle and watch them move, they should move in unison, if they don’t adjust the cables until they do
5 finally I set the idle, I’d do this one at a time by removing a plug lead then start the bike on one pot and adjust the running side to 1,000 rpm then repeat on the other side. I then start the bike with both caps on, the idle will be high and I reduce it by turning each idle screw by the same amount until I get a tickover of around 1,000 rpm
6 now I whack the vacuum gauges on and check that I’m getting the same vacuum at idle, usually it’s pretty close after the above, and I then fine tune with small adjustments to the idle screws until they’re pulling the same vacuum. I then double check the throttle slides are in sync by opening the throttle (if they’re out by much the gauges will move in opposite directions as you blip the throttle) again I’ll tweak until they’re bang on

You can do all of this with vacuum gauges but I find it to much of a faff and prefer to get there manually before fine tuning with the gauges.

This is just the way I go about it and it works for me however others will I’m sure have different opinions.

Dave
Click to expand...
Dave! Thanks for the elaborate instruction on how you tune your Amals. I'm going to need to tune mine properly this summer and I'm looking into all these procedures. I don't have one of these vacuum gauges but will need to get one. If you guys have a favourite that I can get here in the USA, please send a link. Also, I'm assuming the vacuum gauge connects to the wee pipes at the top of each carb and connect to each other with that short length of rubber hose. When you start out with the mixture screws turned out, do you turn them out all the way and then start turning them in? It's a little confusing the starting point of the screws and where you go from there to baseline the screw settings and whether in or out to fine tune.

Also, I didn't know that the engines can run on one cylinder so that each carb can be set independently. I will look at that. Right now, if I pull a plug wire, the engine will stop, and won't run on one cylinder.
 
Starvingphotog said:
Also, I'm assuming the vacuum gauge connects to the wee pipes at the top of each carb and connect to each other with that short length of rubber hose.
Click to expand...

Yes. Normally a gauge is connected to each stub after removing the balance tube.
Starvingphotog said:
When you start out with the mixture screws turned out, do you turn them out all the way and then start turning them in? It's a little confusing the starting point of the screws and where you go from there to baseline the screw settings and whether in or out to fine tune.
Click to expand...

Vacuum gauges are used to synchronise the throttle slides at idle and above. Use the Colortune* or similar for setting (idle) mixture.

*(Not something I've found any need for although I have used it)

Starvingphotog said:
Also, I didn't know that the engines can run on one cylinder so that each carb can be set independently. I will look at that.
Click to expand...

Yes, if you set the throttle stops artificially high then the engine should run on one cylinder.

Starvingphotog said:
Right now, if I pull a plug wire, the engine will stop, and won't run on one cylinder.
Click to expand...

EI manufacturers generally recommended against doing that. Better to devise a means to ground the lead/cap/plug.
 
L.A.B. said:
Yes. Normally a gauge is connected to each stub after removing the balance tube.


EI manufacturers generally recommended against doing that. Better to devise a means to ground the lead/cap/plug.
Click to expand...

Yes to the first point. As to grounding the removed plug lead I put the spare plug back in the removed cap and earth it with a pair of crocodile clips linked with a length of heavy duty cable.

Dave
 
Starvingphotog said:
Dave! Thanks for the elaborate instruction on how you tune your Amals. I'm going to need to tune mine properly this summer and I'm looking into all these procedures. I don't have one of these vacuum gauges but will need to get one. If you guys have a favourite that I can get here in the USA, please send a link. Also, I'm assuming the vacuum gauge connects to the wee pipes at the top of each carb and connect to each other with that short length of rubber hose. When you start out with the mixture screws turned out, do you turn them out all the way and then start turning them in? It's a little confusing the starting point of the screws and where you go from there to baseline the screw settings and whether in or out to fine tune.

Also, I didn't know that the engines can run on one cylinder so that each carb can be set independently. I will look at that. Right now, if I pull a plug wire, the engine will stop, and won't run on one cylinder.
Click to expand...
Vacuum gauges aren’t essential I just use them to fine tune when setting up and then as a periodic check to see if I need to set the carbs.

I use these https://www.mandp.co.uk/products/davida-system-2-vacuum-gauges-525113 and I have to say they are identical to mine that I bought from Davida 40 years ago to set the carbs on my Guzzi Le Mans when I was 18 years old, I suppose if they work why change.

Dave
 
Went out a spin round Cheshire, Clwyd and Shropshire which was thoroughly enjoyable but my slightly weeping right fork seal is now leaking so time for a new pair of seals.

Dave
 
Dellis said:
Went out a spin round Cheshire, Clwyd and Shropshire which was thoroughly enjoyable but my slightly weeping right fork seal is now leaking so time for a new pair of seals.

Dave
Click to expand...
Seals etc ordered, if I’m feeling energetic I may sort then one evening in the week…

Dave
 
LAB, Dave,
Thanks for following up with this tuning thread. I think that I will look into the Colortune and a vacuum gauge to tune the bike. I think it will take the guesswork out of intake mixture, and then get myself a vacuum gauge to balance the idle speed on each carb by being able to synchronize the air intake. Sound right?
 
Starvingphotog said:
LAB, Dave,
Thanks for following up with this tuning thread. I think that I will look into the Colortune and a vacuum gauge to tune the bike. I think it will take the guesswork out of intake mixture, and then get myself a vacuum gauge to balance the idle speed on each carb by being able to synchronize the air intake. Sound right?
Click to expand...
That’s the gist of it yes.

Dave
 
What did the old oil come out like?

I found that mine came out like water, and suspect that perhaps the Lansdowne damper design gives the oil a hard time.

No big deal of course, just means more regular changes my be a good idea.
 

Similar threads

Schwany
What did you do with your P11 today. he he
2 3 4 5
Replies
96
Views
8,414
Schwany
Schwany
Shelby-Right
What did you do with your Triumph today .
Replies
10
Views
1,550
Matt Spencer
M
CanukNortonNut
  • Locked
Ok what are you getting for mileage with your commando.
2 3 4 5
Replies
93
Views
14,348
CanukNortonNut
CanukNortonNut
V
What did you do to your Norton today?
2 3 4
Replies
67
Views
8,643
Richard Tool
Richard Tool
Back
Top