Lotus Elan and Lotus Elan Plus 2 Forums

Chris, did you swap the tops of the carbs or just the floats themselves?

The top's, both identical 31's, i think i have figured it out (or at least found an issue) the floats on the tops that are playing up are very loose compared to the ones that are working as intended, i suspect they are loose enough to foul the reservoirs which may be why they are sticking (they also have some light scratches on the sides).

I fitted a fresh set of plugs and gave it a run with the +2 tops fitted and seems to run fine (exactly the same as the +2 the tops came off) another issue thats appeared though is i bought a SK sync tool that was recommended by Mr Franck, my no4 seems to be pulling less vacuum than the other three which is odd.... i didn't see that with my old sync tool but then it was bouncing all over the show. Even with fresh o rings and slightly over tightening it isn't getting any better.

Got to love it.......

The White paper has started me reading more of Mr Franck's old posts, that guy knows his webers.

?bouncing all over the show? in my experience most definitely a downstream air leak.

Or a very grotty old gauge...... the new Sk is solid but at 2.5 when the others are at 3. The old sync tool bounced on each bore and worse than that restricted the air flow so it dragged loads of fuel through which made it run like a dog.

Night and day to the new tool plus i'm 90% sure the o rings are sealed. I will check again though as my paranoia won't let me leave it alone

Sounds exactly like the tool I have been using for decades, a Carbtune I think.

I do everything by ear with a tube and then briefly use it to see if the airflows are balanced, not holding it in place long enough to juice up the cylinder and guessing what the mean reading is with the white slug bouncing up and down.

Surprising how effective you can be after time with a rubbish tool, I will treat myself to a proper one whenever I get to play with twin DCOEs again.

That sounds very familiar...

I have to admit i was pleasantly surprised how good the SK tool is, where it would take 20 mins (even then it's down to my interpretation of how far the needle bounces) the Sk tool has a damper in it which really helps so takes seconds, not only that but it doesn't pull loads of fuel through.


I spent a few hours reading last night and i believe the carb balance should be checked at 3000rpm (which i've never been able to do) so might give that a crack.


Between the new sync tool and the pipette it's saved so much messing about.


Does anyone know if the Yahoo group Sidedraft_Central is still going? i keep reading about it but i guess it's an invite only deal as it doesn't come up with searches.

Chris,
Sidedraft Central is going strong.
You do have to register with it and state what preferences you have regarding email updates.
That is weekly, daily or continuous. There is a lot of information there.
Eric in Burnley

Thanks.

for what it?s worth, ie. probably nothing ...From some notes I have made in the past:
The pivot point on the 40dcoe alum. casting for the plastic float 151?s is about .730 inches from the inside of the top cover, the brass float pivot on the older carbs is about 0.90, so clearly the floats should match the carb version or the settings will be goofy...
I floated the brass ones in fuel and had noted the fuel level on the float when floated without restrictions was almost perfectly at the middle height of the float, I would have to check what weight of brass floats they were, I suspect std not light weight ones. Depending on age you may also see a stain mark on the floats that represents where the level sits on the float....so with some measurements...I leave the rest up to you...
cheers
Jack