starting sequence

baz · Apr 20, 2023

Fast Eddie said:
Maybe it’s the light of the camera etc, but at idle I thought it looked fairly blue?

Very yellow when you blip it though.

It will go yellow when you blip the throttle on a well set up engine in my experience

baz · Apr 20, 2023

Don't go expecting perfection with an old designed engine like a commando
In the real world you can end up with the engine too lean
I have in the past ridden my commando at night observing the coloutune
And before I get jumped on by any keyboard warriors yes I know it can be dangerous but you don't know the road I do it on
And I'm not advocating anyone else try it
Basically the coloutune can help get towards a great running engine but it's not a miracle worker

Fast Eddie · Apr 20, 2023

Years ago, my mate used one to set up his Ducati 860 GTS.

He was close to nailing it… when he seized it up… in his shed…

He never lived that one down !

kommando · Apr 20, 2023

Fast Eddie said:
but at idle I thought it looked fairly blue?

But it needed 3 1/2 turns out to be blue so still too large. The yellow on throttle opening needs to be seen in the context of a properly sized pilot jet before it can be analysed, you do want some yellow as it stops that lean stumble as the throttle is opened and the engine does not have enough revs to properly draw the mixture.

Like the Amal there are 2 carbs in each casting, the pilot and the main, there is some overlap but both have their own fuel and air supplies.

Fast Eddie · Apr 20, 2023

kommando said:
But it needed 3 1/2 turns out to be blue …

Missed that part !

Head · Apr 20, 2023

Fast Eddie said:
Maybe it’s the light of the camera etc, but at idle I thought it looked fairly blue?

Very yellow when you blip it though.

it was 3.5 turns out on air screw to get that shade of blue it will need smaller pilot, and its normal i think for the yellow when revs at 3k , this might change when correct pilot is in

baz · Apr 20, 2023

Fast Eddie said:
Years ago, my mate used one to set up his Ducati 860 GTS.

He was close to nailing it… when he seized it up… in his shed…

He never lived that one down !

I'm not that surprised by this
Those dukes are a bit dirty running and getting a perfect blue flame wouldn't be easy
And those dell orto pumpers probably gave the coloutune a heart attack

Fast Eddie · Apr 20, 2023

baz said:
I'm not that surprised by this
Those dukes are a bit dirty running and getting a perfect blue flame wouldn't be easy
And those dell orto pumpers probably gave the coloutune a heart attack

Thing is, there was nowt wrong with it before he started.

And being young and skint, that was the end of his Ducati period !

baz · Apr 20, 2023

Fast Eddie said:
Thing is, there was nowt wrong with it before he started.

And being young and skint, that was the end of his Ducati period !

I had an 860 GT
Probably the best A road bike around at that time
Terrible clutch and gearchanges
So terrible around town
But out on a fast road the response/handling/ braking were brilliant

Head · Apr 20, 2023

Update folks, waiting on 25 and 30 pilots to be delivered tomorrow 35 didn’t do it ,

I did start her earlier she won’t start with choke from cold 2 kicks with choke then one kick without choke and slight throttle she fires up bit rough, she needs choke on and off then to keep her going for 20 seconds or so then she runs on her own ticks over perfect too, when warm she is first kick no choke every time , just home the 25 or 30 pilot will allow her to start with choke only

KiwiShane · Apr 20, 2023

Head said:
Update folks, waiting on 25 and 30 pilots to be delivered tomorrow 35 didn’t do it ,

I did start her earlier she won’t start with choke from cold 2 kicks with choke then one kick without choke and slight throttle she fires up bit rough, she needs choke on and off then to keep her going for 20 seconds or so then she runs on her own ticks over perfect too, when warm she is first kick no choke every time , just home the 25 or 30 pilot will allow her to start with choke only

I would say the 30 should be foirfe

Head · May 1, 2023

No update folks still waiting on few pilot jet sizes here will keep ye posted of outcome

Head · May 8, 2023

right folks,

update , i finally got the 30 pilot jet and same end result still wont start with choke ,my sequence is 2 kicks with choke,then off choke and 1/4 throttle it will start 1st or 2nd kick, to keep her going i have to put choke on and off until she warms a little,
will try 27.5 pitlot this week , still at 4 turns out on air screw and still not getting the correct air fuel burn with the colour tuner
maybe i am missing something folks ?

KiwiShane · May 8, 2023

Head said:
right folks,

update , i finally got the 30 pilot jet and same end result still wont start with choke ,my sequence is 2 kicks with choke,then off choke and 1/4 throttle it will start 1st or 2nd kick, to keep her going i have to put choke on and off until she warms a little,
will try 27.5 pitlot this week , still at 4 turns out on air screw and still not getting the correct air fuel burn with the colour tuner
maybe i am missing something folks ?

Ok so may be "toss for now" the colour tune and wind the screw in 2 turns...to try it for a cold start...

Head · May 8, 2023

KiwiShane said:
Ok so may be "toss for now" the colour tune and wind the screw in 2 turns...to try it for a cold start...

hi buddy, i did have it in 2 turns from cold, still bright yellow flame from colour tuner, even out at max 4 turns still not blue enough, she should start with choke only from cold , might have look at the timing see is that out

KiwiShane · May 8, 2023

Head said:
hi buddy, i did have it in 2 turns from cold, still bright yellow flame from colour tuner, even out at max 4 turns still not blue enough, she should start with choke only from cold , might have look at the timing see is that out

So the bike was running and starting sweet before the jet was extracted ?
Just to refresh my memory ?
Would be nice if you had another carb handy with the stock kit jetting ?
Fine tuning can come later

Head · May 8, 2023

KiwiShane said:
So the bike was running and starting sweet before the jet was extracted ?
Just to refresh my memory ?
Would be nice if you had another carb handy with the stock kit jetting ?
Fine tuning can come later

ya mate the bike started first kick hot or cold before i remover the pilot which was gouged out as was over tightened in her, so i could not make out the size it was either, so im gone thru 45,42.5,40,37.5,35,32.5 and 30 now on pilot, will try 27.5 later, factory spec says 265 mains and 40 pilot, when i start her with 1/4 throttle she wont stay going unless i use choke but after couple seconds choke starts to flood her,
i have taken off carbs 20 times cleaned them 20 times i never touched the needle so that should be ok, i have boyer electronic ignition and set timing few months back never have kick back and in fairness when she is warm it runs 100% ticks over 100% and pulls well thru each gear , like i said only issue is starting her from cold in shed, starts first kick when warm

KiwiShane · May 8, 2023

Head said:
ya mate the bike started first kick hot or cold before i remover the pilot which was gouged out as was over tightened in her, so i could not make out the size it was either, so im gone thru 45,42.5,40,37.5,35,32.5 and 30 now on pilot, will try 27.5 later, factory spec says 265 mains and 40 pilot, when i start her with 1/4 throttle she wont stay going unless i use choke but after couple seconds choke starts to flood her,
i have taken off carbs 20 times cleaned them 20 times i never touched the needle so that should be ok, i have boyer electronic ignition and set timing few months back never have kick back and in fairness when she is warm it runs 100% ticks over 100% and pulls well thru each gear , like i said only issue is starting her from cold in shed, starts first kick when warm

Ok so when you adjust the screw when the engine is warm...does the idle change from one turn out to 4 turns?
I'd ring/email a dealer that sells these kits such as Colorado or Holland Norton works for the supplied jet starting point for that instrument especially the settings/jets for the idle circuit...Sweet people...

KiwiShane · May 8, 2023

Forgot to ask whats the rubber manifold rubber like...?

Fast Eddie · May 8, 2023

Head said:
ya mate the bike started first kick hot or cold before i remover the pilot which was gouged out as was over tightened in her, so i could not make out the size it was either, so im gone thru 45,42.5,40,37.5,35,32.5 and 30 now on pilot, will try 27.5 later, factory spec says 265 mains and 40 pilot, when i start her with 1/4 throttle she wont stay going unless i use choke but after couple seconds choke starts to flood her,
i have taken off carbs 20 times cleaned them 20 times i never touched the needle so that should be ok, i have boyer electronic ignition and set timing few months back never have kick back and in fairness when she is warm it runs 100% ticks over 100% and pulls well thru each gear , like i said only issue is starting her from cold in shed, starts first kick when warm

“carbs” … “them” …

Are you running twin carbs ?

starting sequence

Similar threads