Lotus Elan and Lotus Elan Plus 2 Forums

Hi,
I'm recommissioning a 1972 Sprint fitted with Dellorto's that is proving difficult to start when cold and very difficult when hot. It had not run for seven years. I removed the plugs the last time it failed to start. They were very sooted up. I am not familiar with Dellorto's and wondered if any Dellorto experts out there might have any suggestions.

Thanks

Alan.

Hi Alan,
A good starting point would be to check the float levels are set to the correct height and also to remove all the jets blow out with compressed air and check they are the right ones for that engine.

The first things I would do after that amount of standing time is strip and rebuild the carbs with a kit from Eurocarb and, if you have access to an ultrasonic cleaner, run them through it.

It's difficult to start trouble shooting until you know the carbs are clean and not gummed up with varnish and the like

check out the anti thief switch in the glove box the contacts can get corroded

Are you confident you are getting a good spark

You are using new petrol? After seven years the old stuff will be no good.

Thanks for the replies guys, I've blown out the jets again and replaced the ex. manifold gaskets which were blowing.
Switched the immobiliser switch off and on to prove it works ok. Hot and cold starting now with no problems. Is it cured? I'll take it for a run tomorrow and let you know.

Alan.

Nope still the same problem. Think I was over optimistic thinking I could get away without rebuilding the carbs after standing for so long. Just have work out how to get at the lower rear carb retaining nut, looks a bit difficult.
Alan.

don't under estimate that darned immobilizer/burglar alarm switch in glove box!!!!
I retained mine for originality purposes, but I had to really switch it back and forth several times to clean and lubricate it before it functions properly. several occasions, i'll be driving down the road, and suddenly the car dies, I quickly reach over, pop open the glove box door, and flip the switch up & down, and BINGO, back in service.
Quirky, yes, but I live with it...

Once the front carb is off it?s not too bad getting at the lower rear carb nut. I?m on Weber?s, but that bit is the same, checking the tightness when reinstalling is more tricky, don?t want to over tighten the thackeray washers. Do you have electronic ignition or the standard spark system? While you have the carbs off I?d pull out the distributor and give that a bit of an overhaul, clean, lubricate and make sure the centrifugal advance system is free and not sticking. I?d be tempted to fit electronic ignition while doing this if you haven?t already, and fit a suitable matching coil. Check if you have the reduced voltage system to the coil (12v starting, 9v running) and if so ensure you are getting the higher voltage during starting. Together with a new distributor cap, rotor arm, plugs and plug leads you could then be sure any problems were fuel related and not ignition. While you have all the above off, remove and overhaul your fuel pump, the diaphragm can go hard and the valves can stick, especially if you have left it with petrol sitting in it for many years. Together with your planned carb overhaul you should then have an engine that starts reliably hot or cold. The above is basically what I did when putting mine back on the road after over 30 years and it started first time and continues to do so. Hope you get it sorted and can be out enjoying it on the road again.

Although I get what BBB is saying my advice would be to try and isolate the fault first, before throwing lots of money at it. New replacement parts - including electric ignition changes - are no guarantee of a cure.

I?d check things one at a time - just concentrate on carbs if that?s what you want to focus on first, then if still not good move onto other items.

Just to confuse things, most carb faults are electrical !

Let us know how you get on.

Regards
Richard

AlanG wrote: Just have work out how to get at the lower rear carb retaining nut, looks a bit difficult.

It is tricky but not too bad with the right tool. In my case I use a "mini ratchet" and 1/4" drive socket then reach up from under the front carb. It is tricky to get the socket/ratchet on but once you have you can get the nut off with out much more fuss.

The mini racket is basically a like racketing spanner that takes standard bits, for example
* https://www.amazon.com/Tacklife-Screwdr ... B07895C665

Thanks for the comments. Carbs removed. No problem once engine was jacked up. Will rebuild them soon as rebuild kits arrive. I will also replace engine mountings as the rear carb was fouling the bulkhead.
Alan.

richardcox_lotus wrote:Although I get what BBB is saying my advice would be to try and isolate the fault first, before throwing lots of money at it. New replacement parts - including electric ignition changes - are no guarantee of a cure.

I?d check things one at a time - just concentrate on carbs if that?s what you want to focus on first, then if still not good move onto other items.

Just to confuse things, most carb faults are electrical !

Let us know how you get on.

Regards
Richard

One thing at a time- ALWAYS. This is a Lotus you are dealing with.

I wasn't saying electronic ignition must be fitted and the coil must be replaced, just that if you are thinking of it, while the carbs off is a good time to do it as the access is so much easier. I still think on a car that has been laid up for 7 years a basic overhaul of both the fuel pump and the distributor make sense while you have easy access as both can be a cause of poor starting. Neither are particularly difficult to do and the cost of basic overhaul parts is pretty cheap and they are readily available. Personally, if the carb overhaul doesn't fix it, i'd wish i'd done the pump and distributor first time round to eliminate them too, but we all have our own way of doing things and it was just a suggestion of what i'd do in the circumstances based on having just brought a Plus 2 back to life after over 30 years off the road.
Let us know the final solution.