Running Rich

[Dudly]

Hello all-
Ok the 79 Spitfire Is safe in its new spot in the garage. (Daughter named it "Sushi" by the way.
I seem to be having a problem with running rich and a little "chugging". At first I thought it was vapor lock, as it has been well in to the humid 90's here in NE Ohio. But as the evening cools the issue seemed to continue. My carb is stock with the auto choke. I am about to replace the vacuum lines. Is it possible that the auto choke is stuck and or causing the problem. It has electronic ignition and seems to be working ok.

Sushi only has 35K and has not been run very hard in her life. Could that also be the issue?

(Yesterday she seemed to really enjoy a flat out run round the block).

Thanks

 

[Percy]

Doo-right,

Sorry to hear about the "chugging" have you considered replacing "auto" choke with manual?

 

[Dudly]

Percy don't you mean Do-wrong?

I do think that is a good suggestion. Yesterday I did advance the Idle and pulled plugs and cleaned them. Both of those things seemed to make a positive diference. Tore around the block after that fun fun!!!

This evening vacuum tubes will all be replaced. See where that leads me. SpitfireGT6 online mag had some nice suggestions too.

Re choke, I must decide now between new tires or manual choke this month.

What to do, what to do.

 

[DougF]

If you "tore" around the neighborhood yesterday, then I'd look into tires first.

 

[tosoutherncars]

Hiya Dudley,

I've got a Midget with the same engine. The original CD150 is notorious for running very, very rich for a number of reasons, including the horrible water choke. I'll see if I can find some links that might help.

In increasing $ / time / hassle, I would suggest a few options:

- rebuilding the choke and carb, and resetting both

- upgrading to either an electric or manual choke

- Ditch the carb, keep the stock manifold and run a single SU. (Probably what I'd sugest for someone on a budget, with fair mechanical abilities.)

- Ditch the carb and manifold, and replace with a Weber DGV (see below)

- Ditch the carb and manifold, find a dual SU setup (Nice, looks great, good power & parts support, looks stock)

- Ditch the carb and manifold, go for an aftermarket dual DCOE setup (fairly big $$)

I was so frustrated at mine that I replaced the whole thing with a Weber DGV (electric choke) which has been fantastic so far. Better starting, increased power, easier to adjust, sounds great. Kits on ebay for about $300.

More info when I dig up some links...

 

[tosoutherncars]

My hero, John Twist (do a search on You Tube and you'll be busy for hours!) wrote an EXCELLENT article covering the most common causes of running rich, specifically for the CD150 and others with the water choke.

--link here--

Rebuilding the choke...

https://www.sterlingbritishmotoringsociety.org/files/choke.pdf

A few choices...

https://www.triumphspitfire.com/carbchoices.html

Typical DGV install

https://www.kosier.net/spitfire/Weber.html

DGV kit

https://cgi.ebay.com/ebaymotors/32-36-WEB...emZ360059009783

 

[Percy]

Has anyone used the Moss manual choke conversion kit, part #386-325 with any success?

 

[tosoutherncars]

Ouch! $140 plus shipping? For that price you could probably find a used dual SU setup... AND part of the cost of two rebuild kits...

https://cgi.ebay.co.uk/Twin-SU-carburettors-for-Triumph-Spitfire_W0QQitemZ250255267111

Or a very-good-condition single SU. Or half a brand-new DGV...

I suppose it would be worth finding out whether the 'universal' manual choke conversion kits would fit. I know the "Help!" section of my local parts store has a kit with several different sizes of cover. Price under $20.

 

[DrEntropy]

Check with NAPA, too. I recall they had a "conversion kit" for a manual choke a number of years ago. It weren't elegant but I recall it WORKED.

 

[DNK]

Hey, is running Rich better than running Poor?

 

[DrEntropy]

I'd prefer: "runnin' FAT."

...sounds SOOOO much more "contemporary" y'know. :smirk:

 

[DNK]

You can tell you know racing.
said that to a mechanic friend of mine and he gave a the dumb stare.

 

[DrEntropy]

I don' know JACK.

 

[DNK]

Jack 's a waiter at the local breakfast place.

 

[Dudly]

Thanks everyone, what is the deal with the water choke. It interests me that after putting all this restrictive emissions control on the cars actually run less efficient.

Oh well, this choke issue will keep me out of trouble for a few weeks. Hope to have things sorted, including new skins before Mid Ohio!

Goal is to drive her there park in the infield and just soak it all in.

P.S. Thanks for the links tosoutherncars

 

[tosoutherncars]

Let us know how it goes!

 

[Dudly]

Thanks, boy that Weber on e-bay sure looks tempting.

Also love that SpitfireGT6 online mag.

 

[RonMacPherson]

The water choke (automatic choke systems) was a "suggestion" rather than a mandate from the EPA. In their opinion lots of people were not pushing their choke cables in while driving their cars, everything from Austin Healeys to Hondas, and the EPA wanted to reduce the amount of emissions being produced.

So they "requested" the auto manufacturers to all go with auto choke systems that did not need to be unset when driving.


Obviously they did not do a lot of research on the subject...

 

[tosoutherncars]

Thanks, boy that Weber on e-bay sure looks tempting.

Also love that SpitfireGT6 online mag.

Dudly,

Some others may pooh-pooh it and suggest the spendier SUs or DCOEs, but my DGV was easy to set, goes like heck, and sounds fantastic (big growl when the large secondary opens.) Let me know if you'd like, and I'll see if I can get a video clip.

-Duncan