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TomChar
08-23-2012, 11:03 AM
Hi all,

I recently bought a '74 TR6 with dual MCHH carbs. Car runs well, but it's definitely running rich. After quite a bit of searching the web, it appears that the MCHH is somewhat akin to half a DCOE, but I haven't found anything to actually verify that, or even found any techical docs specifically for this carb. I ordered a weber tuning book, that claims to cover the MCHH, but it hasn't arrived yet and the weekend's coming up :-).

Does anyone out there have specific info on these carbs, are the tuning procedures, jets, etc., the same as the DCOE?

Cheers,
Tom

Mickey Richaud
08-23-2012, 11:43 AM
Welcome, Tom!

Just recently I read something about those. Not sure where it came from - maybe this forum...

Someone else will surely pop in here shortly with an answer.

:cheers:
Mickey

hondo402000
08-24-2012, 08:56 AM
Be interesting to see what the book says, if its half a DCOE the good thing is you will only half to buy 1/2 the number of jets, but jetting is not as simple as going down one size, on the DCOE there are 3 circuits, the Idle circuit, the progression circuit and the main circuit and they over lap each other!

I wish you luck if its like jetting a DCOE, only took me 1 year after my engine rebuild to get mine running in the 13.1 to 14 range

by the time you get it right you will be a master of the carbs,

I would suggest you get a air fuel meter and install it so you know exactly where its running

innovate has a digital one, dont get the hand held units they suck

Hondo

DNK
08-24-2012, 10:24 AM
...
I would suggest you get a air fuel meter and install it so you know exactly where its running

innovate has a digital one, dont get the hand held units they suck

Hondo

See
HERE (https://www.britishcarforum.com/classifieds/showproduct.php?product=550&title=innovate-lc1&cat=19)

TomChar
08-28-2012, 08:27 AM
Thanks guys,

In my searching I came across Redline, and sent their tech guys an email. I received a surprising quick and rather detailed response from them, describing the MCHH's as exactly that, half a DCOE. Alas, they are no longer in production, but are still serviceable.

With the info on their website and Bud's response, I've gotten the car to run much better, although not quite inline with the proper tuning specs. At this point I'm still tinkering a bit. A synchronizer is something he's recommended to help with tuning, although with only two venturis's, tuning *should* be much easier than with, say, you guys with triple DCOE's.

Tom

hondo402000
08-28-2012, 07:03 PM
play with anything long enough and you get really good at it,

Hondo