Lotusfab

Sorry misread your rpm 3000 is main jet. Go up two sizes and see.

I am running HC pistons, but LC carbs so my set up is different. I tried all of the jetting for the 45M carb using my 40H carb. I found the mixture was far too rich, the progression holes in the carb body are different. In the end I left the smaller 35 mm choke in with the standard 40H jetting, but a few sizes up on the idle jet. Now perfect. I stumbled across the solution by rejetting and testing. It takes a lot of time and effort. If you have a standard engine and everything is good ie no air leaks, carbs good condition and floats correct height. I think the stumble is probably caused by weakness in the mixture. Its not at main jet at the rpms your talking about so the solution is confined to the idle jet. So if your pump jets are clear and adjusted correctly two things you can try. Increase the idle jet size by 2 and see how you go or try a richer idle jet holder. There is a table for them with the numbers that tell you weather its leaner or richer. You could try the smaller choke, it makes the engine more stable at lower rpms, but can degrade it at its maximum performance. My car made 180 BHP on the rolling road at about 75 per cent throttle. Alternatively, spend £300 with Northampton Motor Sport who can switch out the jets on the road under load. They will get to the solution much quicker if your fed up messing around.

Thanks. Well done for having a go. Persistence pays off. It took months of work to refine it with countless changes of jetting all to arrive at a very simple but unexpected solution.

Car just had its final MOT the tester was impressed with the emissions, I was worried as always…Looks like the tune at Northampton Motor sport was worth it, although they did say it wasn’t really necessary to adjust anything. We went up one jet size although they said it could be left. It took me ages to solve the stumble problem, but have to say its now as good as it can be. The solution was not the jets, but to reduce the choke size. Remember I installed forged HC pistons. Over 1000 miles now done and it drives really well. Such a difference to when I first drove it! Anyone who has tried tuning these cars will understand why the numbers below are impressive.

If anyone wants to see this car it will be at the NEC classic car show on 12/13/14 NOV.

Hi Dave, wow thanks for that! I may have sourced some,but will be in touch. Thabks.

Anyone got any of these to sell please?urgently need one to make up a wheel centre that fell off! They are 60 mm centre hole fitting. Thanks.

Clean the grease off and Write on each shim Numbers 1 to 8 depending on the cylinder, I or E with a marker. Then if you drop them all its no problem.

As above, make sure when you do the timing it is set at 3000 rpm or whatever the higher figure is in the manual. The reason for this is the engine will spend most of its life operating around the higher rpm. When it reduces to idle you will find its around 8-10 if the distributor is in good condition.

Well done. Blow them through with compressed air and wrap them in something until you get to putting them back on.A Lot of bits on the car do take persuading to get off, but they all come apart eventually. Tracking down tools that work is half the battle. Getting the bits out of the camshafts is an essential bit of the build. Good luck with the rest.

Mmm, I have taken out quite a few. Make sure the allen head is very clean so the allen key can get all the way in. I would soak it in wd40 overnight and try the next day. Heat might help. Good luck, they do come out if you persist and they are tight. Try clamping the camshaft on a bench and a long arm allen key.

Try autosparks, I get all my stuff from there and that is a standard connector. Reuse the housing. Also buy their crimp tool if you havnt got one, the ebay ones are cheap, but most are useless.

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Thanks David. That looks good!

Have you got a link please?