Lotus Elan

Access to Rear Stromberg Float Bowl o-ring : US Spec S4

PostPost by: bdea » Mon Dec 31, 2018 1:11 am

20181230_140553.jpg and
brass covered plastic jet cover

Trying to access the rear carb float bowl o-ring. What is the easiest way:

1- Unbolt the right motor mount and transmission mount, raise the motor and transmission?
How much clearance above the footwell can I get? It seems you need 1.5" minimum clearance between the brass covered plastic main jet cover and the footwell to remove the cover. I read somewhere on the forum someone has done this, but wasn't sure if it was that successful over doing # 2? I prefer this!

2- Is it better to remove:
a) the carbs at the US emission adaptor plate?
b)remove the carb and US emission plate as one unit?
Why is one better than the other?

I know the access to the bottom rear nut is the worst, requiring a modified shortened 1/2" wrench and alot of chosen words!

20181230_164159.jpg and
rear mounting nut access
20181230_154905.jpg and
brass covered plastic jet cover
20181230_140633.jpg and
brass covered plastic jet cover to footwell clearance
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PostPost by: mbell » Mon Dec 31, 2018 1:18 am

Can't comment on best solution but if you go for 1) I'd also remove a bolt and slacken the other bolt from the left engine mount to let it rotate and avoid potential damage to the left engine mount.
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PostPost by: bdea » Mon Dec 31, 2018 3:11 am

Good Observation and thanks for the tip on the left motor mount bolt!
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PostPost by: SENC » Mon Dec 31, 2018 4:39 am

Having recently removed my carbs, my plan was to remove them as an assembly, but a rotted motor mount had it sitting too low. I was able to get to the nuts, though, and remove the carbs, then jacked the motor and removed the intake manifold and adapter plates.

I'd remove them - that way you can inspect them and do any work necessary.
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PostPost by: 69S4 » Mon Dec 31, 2018 7:27 am

Don’t try to remove the float bowl in situ. Even with the engine mount bolts removed and the engine jacked as high as it’ll go it’ll still be a difficult job with very limited access. If you damage the gasket you’ll be taking the carbs off anyway. Getting the plastic jet cover out to replace the o ring is definitely a job for care and a steady hand on the bench. Removing the carbs as a unit isn’t that hard, it’s only the one nut you mentioned that’s awkward.

If you do take them off as a unit you might want to have a pair of new manifold o rings available as well. They usually swell up with use and are too big to go back in. They do shrink back to size over a week or two but replacing with new is a good idea as a leak throws the idle carburation way off.

You should have more clearance to the footwell than the picture shows (my rule of thumb is can I get my fingers between the carb bottom and the footwell). Engine mount issues are the usual cause and iirc there is some difference between the Weber and Stromberg arrangement (although I can’t remember what it is at the moment)
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PostPost by: collins_dan » Mon Dec 31, 2018 3:00 pm

Mine were leaking this spring when I started the car up, so just pulled both carbs as a unit. It’s very easy. I do find that a short wrench that makes that left rear bolt easier to access and remove. Good luck. Dan
Last edited by collins_dan on Fri Jan 04, 2019 10:46 pm, edited 1 time in total.
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PostPost by: bdea » Fri Jan 04, 2019 4:50 am

20190103_151755.jpg and
Normal Motor Height
20190103_151824.jpg and
Raised Motor Height
20190103_145815.jpg and
Motor Mount at higher position
20190103_145959.jpg and
2" height gain
20190103_150200.jpg and
20190103_153358.jpg and
20190103_154557.jpg and
Motor Mount might be sagging

UPDATE: Decided to unbolt motor and transmission mounts!

Wanting to startup the motor after 7 years of slumber and not have to resync the carbs just to start it. Also the pain and suffering of getting to the rear carb mounting nut. Was it worth it? It took 2.5 hours and forgot where I put the o-ring!
Forgot the note from above poster about removing the bottom bolt on the drivers side motor mount so it could pivot upwards. Removed the nut to the second bottom bolt, went to raise the motor with floor jack under oil pan to relieve the pressure on the bolt so I could remove it, then I forgot to remove that bolt! Raised the motor to access the o-ring anyway. May have twisted the mount,

Motor Mount OK! No Cracks!

Look at the attached pictures of my work, less the senior moments of clarity!

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PostPost by: Mike Ostrov » Fri Jan 04, 2019 7:43 am

Hi, Brad. Glad you are ready to fire up the Elan.

Wish I could remember the source for my "no hole" float bowls on my 1725 cc Stromberg Twin Cam in the Elite/Elan Mk II with the C-4 automatic.Someone on the list might have the details.

Can help you anytime till next Monday, as I start my 10th annual, 9 days of IRS tax re certification classes, 9 to 4 for my volunteer tax preparation at our local senior center.

Cheers. Mike.
[email protected] or (5l0) 232-7764
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PostPost by: Bombay Racing Green » Sat Jan 05, 2019 4:34 pm

Hi Brad,

Nice to see the progress on your car. I was the chap with Mike and Jon when we went for lunch just before Christmas.

All the best,

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1971 S2 Europa
1968 +2
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