CB Performance Dellorto DRLA update kit

[the beard]

Anyone out there fitted one of these?  I just fitted one to my 1956cc w/ 40 drlas.

The kit did not come with lead plugs for the small idle air bleed holes.  The instructions say to fit them.

The engine went from perfect smooth running with lovely idle 14.5 a/f ratio to possibly the worst running engine I've ever heard.  Idle a/f is now 20 and runs at either 500 or 4000 revs or dies.  And gets super hot super fast.

No other changes made, carbs exactly the same as before.  I'm guessing becasue the new tall idle stacks come with their own top air bleed that I should try to plug those original air bleed holes in the top of the carb (pic attached).  Anyone come up with a way to plug them effectively?

Thanks
Phil

[Bruce]

Didn't you also change the main jet?

The tall idle jet holders with the lead plugs have nothing to do with the new venturis and horizontal discharge tubes.  They should not affect the A/F ratio or driveability.  With or without the plugs will not change the A/F ratio either.  If you didn't trust them, you can go back to your original short idle jet holders.

[Rob DVKK]

When I put them in my 45 dells on my old 1914. I had to step up on main jets. The E tubes and main air corrector stayed the same. I was running a 200 air on the main jet stack. The vent in the update kit is much larger then the stock one so the signal to the main jet less.

This is what I found - but I wasn't running an LM-1 at the time.

The plugs are to stop the dirt from getting in the holes and clogging up the circuits and I used the ones that came in the kit. You might be able to use lead shot if it still available. May be a firearms store might be able to help. Sound a little weird to recommend a arms store for car parts, but recently the one near me was the only shop around that had ear muffs in children's sizes.

[Gabetion2000]

I would think by not pluging the holes with the lead balls would cause a lean condition in the idle circuit. Due to the idle circuit having 2 feed holes ( the one in the carb and the one in the jet stack). My only experience with the kit is , I never got the car to run right. I ended up taking it back out and just using the jet doctor kit ( which is awesome).  My 2 cents.

[the beard]

Actually I had 148 mains and now use the kit update ones which are 150.  So a slight increase on the mains.  However I'm only talking idling - as I say,  before changes - everything perfect and after kit installed this engine will basically not even run.  Backfiring/popping/dying off straight away and really lean.  The vents have gone from a 34 to 36 which is going to make it idle a bit worse but this is crazy.  I'll pop the old idles back in to make sure it's nothing to do with the new idles.  If it still runs like a total bag of poo I'll take everything out and put it back to how it was before and check the running again.  Airs in the CB kit are 165 (down from 180s that I had) so again richening it up for those bigger chokes but that's all on the mainjet circuit.  Gotta figure out why this kit has destroyed my idle!
Cheers
Phil

[Bruce]

....  The vents have gone from a 34 to 36 which is going to make it idle a bit worse ......

The size of the venturi has absolutely NO effect on the idle whatsoever.

[GreenTom]

I was running DRLA ubde kit with my 40s on 1776ccm. maybe it wasn't perfectly smoth (the worst moment was near 80km/h till 100km/h on 4th gear, but when you runnthem hard the car was just jumping on high revs.. Ubdate kit just love hi rews (in my opinion) but eaven with the bad running in that speed gap the carbs runn realy god on progression.

I took out the venturies and discharged tubes cuz I have to small inlet valves (35,5mm) but I hept the "jet doctor" with the tall idle jet holders really cure the stucked jets.