Idling problem
- Thread starter Becker
- Start date
Laverdalothar
Hero member
- Location
- Germany
to make the bike start well, they need to be synchronized... Believe me, I had several bikes with not synchronized ones and they were starting shit, running rough and cutting out after 20 Seconds latest. Rough synchronization by the eye is enough though
piranha-bro2
Hero member
- Location
- Melbourne
Makes perfect sense that they need to be synced. Otherwise you're getting totally different richening effects in each cylinder - a recipe for crap running and fouled plugs.
Exmoor beast
Hero member
- Location
- Minehead,Somerset, ENGLAND OF COURSE
This is correct- they are just bungs- open or closed...or leaking down a bit!
Laverdalothar
Hero member
- Location
- Germany
sorry, but this is not true. Just like any slider, they are not digital but linearly opening. In Extreme, one could be closed, one half way open and one fully open, which would cause the first cylinder not to fire, the second to fire fine and the third one to fool the plug.
No Laverda (except maybe at minus 10° Centigrade...) needs full choke on starting (or something else is sett wrongly...) My 1000 SFC f.e. always started best on 2/3 of choke, the Jota on 1/2 open chokes, maybe a bit more (while they were still on Dell'Ortos). Personally, I always start a bike by first pressing the button and then slowly open choke until it barks to live to make sure the plugs do not get fooled.
Certainly, but I don't run with the choke on. When they're down, they're down.
Choke always closed as soon as possible and engine warmed up a bit by holding the throttle around 1500 revs.
Paul
You could probably start the engine with the choke to two cylinders disconnected completely. You could probably start it just by squirting fuel in with the pumps.
Otherwise, the starting procedure will vary from the state of tune, of wear, outside temperature, altitude, jetting etc.
Paul
Laverdalothar
Hero member
- Location
- Germany
Paul, Choke is for starting. Naturally, they need to be closed once either the bike has warmed up enough to run without them or you role off with holding the bike alive with gas. However, cold-starting a triple without choke is - even in normal riding weather conditions - sometimes hard. A bit to much choke (especially with original ignition system and/or a weak battery etc.), and you piss your sparks out with no chance to get them running without drying them first. This circuit is VERY sensitive to setting and the bike to the starting procedure to my experience. I solved a lot of starting issues by simply setting them to equal movement and fully close and only engaging choke while already pushing the starter button.
Try it: set the chokes so that one only just opens, one is half way open and one is fully opened and start the bike. In most cases, the bike will run on 1-2 cylinders...
it is not about alternative starting procedures, it is about how to improve starting and cold running in idle under standard conditions.
Richard from California had exactly that issues 2 years or so ago. I was in San Francisco for business reasons and he asked me if I could maybe help him on his freshly assembled Jota. The bike started instantly, ran a bit rough and cut out after maybe 10 - 15 Seconds of running. You could re-start it again and again, it always cut out after some seconds of running. I asked him what he already adjusted and he said he put everything to company specs.
I checked the choke sliders first just to find them exactly as I described above: 1 almost closed, second cylinder half way open, third almost fully open. Interestingly, the left carb was set to 2 turn out (idle mixture screw), center to 1,5, right one to 1 turns out to compensate for the different slider setting I assume.
I set the sliders to even opening and fully closing, turned in all idle mixture screws and 1,5 turns out and the bike started with half choke open (before only on full choke) and idled perfectly without cutting out. Now you could argue that it was the idle mixture screws causing the issue. which I checked and wich was not the case.
Try it: set the chokes so that one only just opens, one is half way open and one is fully opened and start the bike. In most cases, the bike will run on 1-2 cylinders...
it is not about alternative starting procedures, it is about how to improve starting and cold running in idle under standard conditions.
Richard from California had exactly that issues 2 years or so ago. I was in San Francisco for business reasons and he asked me if I could maybe help him on his freshly assembled Jota. The bike started instantly, ran a bit rough and cut out after maybe 10 - 15 Seconds of running. You could re-start it again and again, it always cut out after some seconds of running. I asked him what he already adjusted and he said he put everything to company specs.
I checked the choke sliders first just to find them exactly as I described above: 1 almost closed, second cylinder half way open, third almost fully open. Interestingly, the left carb was set to 2 turn out (idle mixture screw), center to 1,5, right one to 1 turns out to compensate for the different slider setting I assume.
I set the sliders to even opening and fully closing, turned in all idle mixture screws and 1,5 turns out and the bike started with half choke open (before only on full choke) and idled perfectly without cutting out. Now you could argue that it was the idle mixture screws causing the issue. which I checked and wich was not the case.
Last edited:
Legs
Hero member
- Location
- Adelaide Hills
Thanks for the input everybody, have set the choke slides up as suggested. Will see in a day or two how she runs.
AndyW
Hero member
For a while (until you came along) I ran with two of the plungers disconnected from their cables (retention springs still in place) so as to only operate a single choke when starting and thereby reduce plug fouling. Seemed to work well though that is now the cylinder pulling a bit of oil through,,,
You should have disconnected all three and just used the accelerator pumps to squirt neat petrol into the bores.
Come to think of it, the ideal solution would probably be two central float bowls. Just flood one of them with a tickler and off you go.
There was a young man from Bremen
He never used any choke
He'd give it a tickle and then it awoke
That funny young man from Bremen
Paul
Where's the problem, Clem? You only need to check/adjust each pair of floats individually. Some people use a fixed guage, I use a steel rule marked at 0.5mm increments. You do of course need a keen eye, a sense of orientation and a little experience with the spring-loaded float valve plungers.
Attempting to do this with the carbs still on the engine/in the bike, as many do, is doomed to failure.After setting up carbs on the bench, I rarely require more than 2-3 minutes on balancing and tweaking idle mixture to achieve a steady idle and clean pick up. Road tests normally confirm my settings. Of course, all slop in carb linkages is removed and valve clearances are finely adjusted beforehand... failing to do this first can keep you busy on the balance guages for an entire afternoon.
I prefer to invest an hour or 3 in preparation and achieve acceptable results within minutes, instead of fiddling for hours and getting nowhere.
piet
piranha-bro2
Hero member
- Location
- Melbourne
Clem, I also wondered how you could ascertain an increment of 0.1mm when dealing with float height. Everything you say above is absolutely true of course, Piet, but doesn't really address the point Clem was making.
motoddrob
Hero member
- Location
- S/W Australia
I never run my motor on choke. Once it starts it's switch off. Now with the Mikunis I don't use the choke at all. Couple of twists of the throttle and it'll fire right up.
Laverdalothar
Hero member
- Location
- Germany
Well - in this case, the floats were 0,6 off (OK - 0,1 out of maximum tolerance, but actually 0,6 out of correct adjustment). it is not a big thing to measure that, especially with the right tools...:
Float hight measurement tool Stein-Dinse