Lemans I Starting Issues

[Chuck in Indiana]

I've posted this before, but it's instructive..

[blackcat]

Chuck, thanks.

I got it running yesterday but it wouldn't start again and this was after removing, cleaning and adjusting the floats. The lack of gas fumes made the gas starvation suspect even though there was gas in the tank, I removed the gas line from one of the carbs and turned on the gas tap. It was barely trickling out of the hose. I had cleaned both of the tank filters but there must be gunk in the screens now that gas has been washing the interior of the tank.   

So I will investigate this morning.

[blackcat]

I am coming to the conclusion that these original carbs are NG; I got the bike running but it won't idle and I've taken both carbs apart, installed new needles, jets and blown out the passage ways. I'm guessing the slides are passing air as the carb bodies have some scoring.  Just to make sure there isn't another problem, I swapped the carbs from my 1000S with the same needles and slides in the bell cranks and it started right up and I got it to idle within a few minutes. 

Can't imagine anyone re-sleeves Dellorto's like they do Amals and if they do what the cost might be compared to just buying new carbs and having someone strip the anodized finish.

[moto-uno]

 Not sure how many hours your carbs may have , (not sure if this has been suggested already) but the earlier
units had a marginal thickness boss that the idle adjustment screw pushed on for controling the slide position
at idle . I put a lot of performance parts on my Le Mans 2 early in it's life and my 40 mm dellortos still idle well
and have well over 150k kilometers on them. You can however see how indented the idle stop on the slide is.
I'm assuming the "O" ring on the idle mixture screw is fine and the choke plunger rubber on the bottom is still
sealing well with good spring pressure on it .  Peter

[blackcat]

Not sure how many hours your carbs may have , (not sure if this has been suggested already) but the earlier
units had a marginal thickness boss that the idle adjustment screw pushed on for controling the slide position
at idle . I put a lot of performance parts on my Le Mans 2 early in it's life and my 40 mm dellortos still idle well
and have well over 150k kilometers on them. You can however see how indented the idle stop on the slide is.
I'm assuming the "O" ring on the idle mixture screw is fine and the choke plunger rubber on the bottom is still
sealing well with good spring pressure on it .  Peter

I modified the slides as per the suggestion with later slides and when I swapped carb bodies I just used the same slides and needles on the 1000S carbs with no issues. And I've screwed the idle adjustment screws in all of the way on the original carbs with no improvement on the idle, so it might be the passage ways for the pilot jets that are the problem. 

All of the o-rings have been changed and the choke plungers are new.  The problem is that the carb barrels have slight scores which can't help but I would think that it would at least idle.

[moto-uno]

 I have more than a few scores on the throttle slides , unless they rattle around in the bores I'm doubting the slides are a problem.
If you have some carb or ignition cleaner with a tube on the can , spraying into the mixture screw hole should have spray coming
out into the carb bore at the idle holes (intake manifold side) and from the idle jet in the float . If not you have plugged passage in
carb body . Peter

[blackcat]

I have more than a few scores on the throttle slides , unless they rattle around in the bores I'm doubting the slides are a problem.
If you have some carb or ignition cleaner with a tube on the can , spraying into the mixture screw hole should have spray coming
out into the carb bore at the idle holes (intake manifold side) and from the idle jet in the float . If not you have plugged passage in
carb body . Peter

Peter,

Thanks, I will give that a try and see what happens.