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Any Weber DATR experts in here?

PostPosted: Sun Apr 05, 2020 4:56 pm
by Per
All, I have posted in the relevant Lancia Beta forums as well but final discussion has not given any response. So here goes:

I have a 1978 HPE 2000 which runs too rich. I have cleaned the carb in ultrasound bath and blown through all channels with compressed air. Jets are all correct according to spec. Float is new (old one gave same result). Needle valve is new and correct spec. Gasket new and diaphragms new. Even though I turn low speed jets (some call them idle jets) fully home and idle bypass screw fully home it still runs a bit rich. CO does not get below 7%. A squirt of easystart kills the engine immediately. Jets all look ok.

Is there anything I have overlooked? Can the jets be worn to this extent even though they still look ok?

Re: Any Weber DATR experts in here?

PostPosted: Sun Apr 05, 2020 6:02 pm
by thomaslk
Hi Per,
i had a DMTR (manual choke version of DATR) on my Fiat Ritmo85 some 100 years ago - but unfortunately i canĀ“t remember any details.
Generally i would suggest to check the butterfly opening/butterfly stop at idle conditions. Maybe it is too wide open so that the idle system is not working efficiently.
rgds
Thomas

Re: Any Weber DATR experts in here?

PostPosted: Sun Apr 05, 2020 6:10 pm
by Per
Hi Thomas, butterfly has been dialled back to where the engine will not idle at all, then out again. The idle system i. e. the tiny holes at the butterfly do work: Pulling the lead on the cut off solenoid on the carb immediately kills the engine.

Re: Any Weber DATR experts in here?

PostPosted: Sun Apr 05, 2020 6:20 pm
by thomaslk
Hi Per,
that sounds very reasonable - so butterfly position seems to be ok. On the other hand 7% CO are definitely too much as you mention. Any changes in fuel delivery like new fuel pump? Do you see any "dripplets" when looking into the carb with idling engine (aircleaner off)?
Thomas

Re: Any Weber DATR experts in here?

PostPosted: Sun Apr 05, 2020 6:33 pm
by Grant
Just put smaller idle jets in it Per..they are cheap enough :wink:

Re: Any Weber DATR experts in here?

PostPosted: Sun Apr 05, 2020 6:37 pm
by kees
Float level correct??

Re: Any Weber DATR experts in here?

PostPosted: Sun Apr 05, 2020 7:35 pm
by Per
Fuel pump replaced with electric, no change. Stops clicking when priming done, no dribbling. Float level per book.

Re: Any Weber DATR experts in here?

PostPosted: Sun Apr 05, 2020 7:35 pm
by thomaslk
Choke fully open? Ignition ok?

Re: Any Weber DATR experts in here?

PostPosted: Sun Apr 05, 2020 7:37 pm
by Per
Choke fully open. Ignition now Pertronix, strong steady spark. Timing per book and behaviour when tweaking also indicating ignition correct.

Re: Any Weber DATR experts in here?

PostPosted: Sun Apr 05, 2020 8:14 pm
by thomaslk
All spark plug tips same colour or one dark outlier?

Re: Any Weber DATR experts in here?

PostPosted: Mon Apr 06, 2020 10:52 am
by Per
All plugs same colour, a bit sooty of course but not overly so as most of the test driving (and normal driving to be honest) is in the higher rev range.

Re: Any Weber DATR experts in here?

PostPosted: Mon Apr 06, 2020 4:54 pm
by Per
I tried a pair of new smaller primary jets. The engine struggled as much as it should, so the correct ones have gone into a bottle of paint thinner. There they will stay for a couple of days. I forgot to mention the car had been sittkng atound doing nothing when I bought it a year ago. Now that I have fixead all the issues to get an MOT or rather the Norwegian equivalent the only remaining trouble is the iffy running.

Re: Any Weber DATR experts in here?

PostPosted: Mon Apr 06, 2020 7:53 pm
by Grant
Per.. Take the emulsion tubes out and clean them inside and out and all the little holes in them too, you can use a piece of stranded copper cable doubled over for the inside.. it works great :wink:

Re: Any Weber DATR experts in here?

PostPosted: Mon Apr 06, 2020 7:55 pm
by ChrisP
Just a thought and I am no expert, but if your fuel delivery system is fine
and your timing and ignition is fine i can see only two ways your car can run rich
A) not enough air
B)your gauge measuring co2 is faulty
Hope this helps
Chris

Re: Any Weber DATR experts in here?

PostPosted: Mon Apr 06, 2020 8:18 pm
by kees
Are you sure it is the correct carb with the correct jets, venturies and float weights?
Cam timing?