Lotus Elan

Tuning

PostPost by: bobm3142 » Fri Nov 18, 2011 5:01 pm

Although I'm no further forward I feel that I am nearing the end of this problem.

I replaced the small ally washers on the pump jets and it made no difference. I have had the timing accurately set (to 10deg BTDC) and checked with a strobe light to show proper advance/retard function. I have had the two carbs balanced (air flows) and the mixture control valves set to give correct combustion (it is now excellent). However, the engine still dies for a second (revs less that 2500 ish) when you ask the car to accelerate. As the revs are increased the mixture becomes very rich (constant not just as you accelerate). The conclusion is that the carbs need the jets sorting out. I don't know what is in the carbs but really suspect that they have been tampered with. I have found a guy, near me, who is really good with carbs and carries all the necessary jets in stock. So I'm off to see him on Tuesday (there goes another ?100 or so!). I'll start with a clean bill of health and have them completely re-jetted to the correct specification and I hope that it will be an end to the problem.

I'll let you know the results.

Regards and thanks.

Bob
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PostPost by: Spyder fan » Fri Nov 18, 2011 9:24 pm

Good luck with that and thanks for reporting back to us all. I was hoping to feel a bit smug about the pump jet washers, but I think you are on the right track and will find rejetting by an expert will do the trickl

Regards
Kindest regards

Alan Thomas
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PostPost by: twincamman » Fri Nov 18, 2011 10:59 pm

ok -I had that problem on the Europa ----25 years old goop and shizen in the tank from sitting -shmutz in the gas tank clogged the filter and would get moved around in the filter to allow some flow at higher revs or would stay jammed and stop the car with fuel starvation---the lean run fouled the plugs and hard starting and poor running resulted ----I have never been able to understand why the plugs foul on a lean run to stall situation but mine did . Perhaps oil fouled the plugs from the seal free valve guides --the elan was a combination of timing being off as in too far advanced and points too close as in wear nub used up -- :oops: Weber jetting is stage 1 -- choke 30mm --main 115 --air corr 200 --pump jet 40-- idle 45 f 9 -- tube f11 for the 105 engine and stage 2 is --choke 32 -- main 120 air corrector 180-- pump jet 40 -- idle jet 45 f 9 [[emulsion f11 ---save your 100 pounds and buy some ginnus -NOW if the motor was set at 18 degrees static [as the elan manual says] you will have this happen as you described yup the manual is wrong ----set the static timing to 10 degrees on the front indicating marks at TDC #1 start the car and set the timing light timing around 20 degrees at 2500 rpm and the car should be happy there as in good idle and take off from stop and smooth acceleration . I use that setting on both the 7 [105 ] hp and the elan 115 hp ---works fine -or the floats are not correct in their drop -good luck and keep us posted -ed
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PostPost by: bobm3142 » Sat Nov 19, 2011 8:17 am

twincamman wrote:ok -I had that problem on the Europa ----25 years old goop and shizen in the tank from sitting -shmutz in the gas tank clogged the filter and would get moved around in the filter to allow some flow at higher revs or would stay jammed and stop the car with fuel starvation---the lean run fouled the plugs and hard starting and poor running resulted ----I have never been able to understand why the plugs foul on a lean run to stall situation but mine did . Perhaps oil fouled the plugs from the seal free valve guides --the elan was a combination of timing being off as in too far advanced and points too close as in wear nub used up -- :oops: Weber jetting is stage 1 -- choke 30mm --main 115 --air corr 200 --pump jet 40-- idle 45 f 9 -- tube f11 for the 105 engine and stage 2 is --choke 32 -- main 120 air corrector 180-- pump jet 40 -- idle jet 45 f 9 [[emulsion f11 ---save your 100 pounds and buy some ginnus -NOW if the motor was set at 18 degrees static [as the elan manual says] you will have this happen as you described yup the manual is wrong ----set the static timing to 10 degrees on the front indicating marks at TDC #1 start the car and set the timing light timing around 20 degrees at 2500 rpm and the car should be happy there as in good idle and take off from stop and smooth acceleration . I use that setting on both the 7 [105 ] hp and the elan 115 hp ---works fine -or the floats are not correct in their drop -good luck and keep us posted -ed



Thanks for the info. Will update after Tuesday.

Bob
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PostPost by: bobm3142 » Mon Mar 11, 2013 11:09 am

Hi all, I know its been ages since I posted my problem and with all the helpful advice I have sorted it. I think that there are a number of lessons from my experience in sorting it so I will write the tail in a new posting. Thanks for all those who helped me. Regards, Bob
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