Engine Cutting Out

Check the point gap. ( Most likely closed)

90% of all problems are the ignition system after you make sure thats all correct then look at the fuel system.

Does it have a fuel filter thats blocked?

rm

ooFunk wrote:

Definately not the points, Had a Mobile Tuning Guy come round and go through the whole engine, ie the Valve Clearences, Spark Plag Gaps, Points, Condenser and Carb.

Like i said its intermittant, surely if it was points this wouldnt be the case.

Im pretty sure its fuel... the tell tell sign i guess is the stink of it!! i Forgot to mention this before, Is it possible that the float is sticking up, the pump is still pumping and therefore its pumping the fuel down the overflow? (Is the second pipe on the float an overflow??).

I dont have a fuel filter, should i install one? I thought they were only fitted to injection models, I can understand the benefits, but will it work ok on a carburetted engine?

Check that your dashpot is not sticking open, this would cause the problems you describe, just take off the air filter and give it a lift through the carb opening, it should lift up smoothly and drop down quite slowly all the way, you may have disturbed something when you put in the new needle, worst case scenario would be the needle rubbing on the jet as it isn't centred properly.

Hope that helps!

Thats a good idea Miniman, ill give that a go in the morning, To be honest i hadnt considered the internals of the Carb,. The Tuning guy i had round gave the Carb a really good clean out so they shouldnt be any Gunk in there that could make it stick. Is there anything to watch out for in that area?

Should maybe i be thinking about an uprated Spring? In a lot of "pre-packaged" Stage 1's they often come with one? I assume they are there to help return the dashpot.

Oil wise, i put in some General oil. Similar to 3 in 1 i guess. I have seen a few debates on this subject and im not sure which to go with. I was putting in same as the engine, 20/50 classic, but i found that i got the symdrome where you lift your foot at high speed and get more acceleration which im told is due to the dashpot in some way. I guess though if that is related to the oil then that scenario is better than the present.

Anymore thoughts are greatly appreciated.

That is caused by a weak mixture and that could be the cause of your other problems.

keith

Wouldnt a weak mixture give this problem all the time though? I pretty confident the mixture is fine, when its not having one of its funny five minutes the idle is very smooth and constant, no hunting at all.

Well i seem to have sorted it... Turns out to be the Valve in the Float. Was sticking up so no fuel!!. Why would the Revs tend to rise before cutting out if it was fuel starvation?? Indication that maybe im running too rich??

Thanks for all the advice and ideas, Still wouldnt mind some feedback on a few other points i made if anybody has the answers.... ie Fuel Filter? certainly would have helped in this situation but will it work ok or too much resistance? also piston spring?

Again Thanks all.... Shes a happy little car once more.

John

You may be running a little rich. It's easy to check with the piston lifting pin. Fuel filter can be fitted. I have run SU's with and without them and found no difference but I know that others here say they stop the float valve from getting dirt in it. The SU piston spring is there to control the mixture not to push the piston down quicker. A stronger spring gives a richer mixture across the range but also results in a greater pressure drop across the carb. Stick with the spring you have if it's set up right.

John