carb help

[evogill]

Lost mixture screw from carb. Put another 1 in and afr is 10.0.whatever i do it will not tickover above 10.0.on afr gauge. The car tickover is now faster without the screw than with it in. Iv had carb off to check underside for blockage...all clear..wouldnt tick over in 1st place thats how i found screw missin. Iv turned screw all way down.3 backwards..reved for 5 secs..same keep turnin out and revin.still only 10.0 on afr. Cars been runnin spot on prier to this

[Trevhib]

Have you got the o-ring in the mixture screw?

Also, I think you set it up by screwing all the way in and 1 1/4 turns out, not three turns.

Lastly, the tick-over speed is controlled by a different screw on the carb.

[evogill]

yes mate, theres a ring on the screw, ordered another mixture screw incase this is a dodgy 1 !! topcat told me a few things to do, so took carb off, stripped bits, got a wash after blowing threw emultion tube !! float pin is fine, the minute holes at end of mixture screw is all clear, took carb to work to day and blasted everything with airline. just refitted carb, guna wait for screw now before firing up.... let you know what happens..fingers crossed!

[Trevhib]

Good stuff, hopefully that will sort you out.

Remember only unwind the mixture screw 1 & 1/4 turns and that the tick-over speed is controlled by a different screw.

[evogill]

will do mate, screw turned up today, only just opened packet. the seal on top of screw looks meaty compaired to mine...fingers crossed. thanks again

[rs250nut]

If you have access to an mot lane or anyone with a basic gas analyser you could get them to set the base co/ lambda. Once it's set shove a piece of blue tack in there.

[evogill]

fired car up tonite...... still same, found a carb base in with some old bits, goin to swap them over tomorrow,

[Trevhib]

Weird. The loss of your mixture screw and the AFRs going off must have been a coincidence. Let us know how you get on with the replacement base

[Junglist]

It's not snapped inside ?

[evogill]

no mate...proper screwin my head up now. tried my carb today..with a diefferent base..still same. tried a rebuilt one off james salt...perfect,...so its me carb....bought large tin of carb cleaner,2 hours of my time ..complete stip..nothing left on. 140 psi of air threw pointy blow gun....twice....refit, excactly same...proper f**ked off. any one with a good carb?it had a rebild kit fitted by mark mark bd 80 miles ago,..all because mixture screw did a ruuner

[Matt Cole]

Like everything 25-30 years old, things wear out.

Sometimes the carb housings just give up and don't respond to adjustments.

[evogill]

just dosnt do owt with screw in or out, just missed out on jrp carb.gutted.
just need nother 50miles on its a full hammering of engine after rebuild and gasket changes that's leaking. was hopin to conker over chrimbo.. probly get sheeted up till easter now. washed my hands of the thing after 2 year rebuild

[JRP]

Just check all gaskets again, and making sure you have no air leaks etc.. Dodgy carb gasket somewhere.

[evogill]

thanks

[Trevhib]

I agree with Jon, I think one of the gaskets is leaking.

Have you got the o-ring between the lobster and the carb?

[evogill]

Yes.got big o ring.

[evogill]

Gotissue solved......£180 carb from cgb. Goin to strip troubled carb.my mates got a electro cleaner.so hes havin it to clean it threw.got car runnin chrimbo eve nite...been for a run this dinner time. All seems fine apart from a smell of petrol around 3k revs when reved hard (only reved to 3.5 still runnin in)..poppin on over run (afr is weak then).its a standard carb. So 80 miles left. Sumps pissin oil out.just got to sort it and il be happy.

[Junglist]

Nice one , getting there

[evogill]

a least I got out finally in it again, if my mate sorts the dodgy carb easy enuf, il ask if hes prepared to do anyones on here if they need them doin

[Trevhib]

Glad you got sorted. Can't go wrong with a new carb tbh. Although once sorted the old one will be a great back-up, or even sell on to recoup a fair amount of the £180.

[evogill]

just glad to drive it!! cant now cos of snow!!! sods law! when dodgy carbs done..and hopefully works good again il probly do this new one, so there both clean with new service kits in....just to be on safe side