Dutton Kit Cars and their owners
Hi - I have a Dutton Phaeton with an RS2000 2.0 litre pinto engine in. It has a webber 32/36 carb manual choke in but is running very roughly. The car starts ok and runs ok in lower rev range but as soon as you press the throttle it splutters and bogs. If it is in 4th gear and I rev it goes through the lower range but as the revs build it again splutters. The situation is improved if when this happens I pull the manual choke out then the car takes off like a rocket. I need to set up the timing advance but dont know what to set it too. I have it set to 10 degrees BTDC but no improvement. Also has anyone any suggestions for setting the carb - I have done a fair bit of reading and tried to set up the lean best idle adjustment but the car is still running like a pig. Any suggestions as to where to go with this would be greatly appreciated.
Think its standard - files attached
Yes it standard , It maybe worth checking the valve timing ,it is very easy to get the belt 1 tooth out , but I still think its an air leak somewhere causing your problem
I checked the belt timing again - the piston is at tdc - the bottom pulley with the timing marks on lines up at tdc with the mark on the engine block and the top pulley 'mountain and moon' marks line up so all seems ok for the belt position. I will go over all bolts again to check for tightness - then i will give up until next week - thanks for all the help so far - I wont let it beat me !!!
Checked all the marks again - all seem ok - timing set to 10 degrees btdc - idle mixture screw 2 turns out - idle speed screw 1 1/2 turns onto throttle - won't start unless i put some more throttle on - misfires when revved - plugs black and sooty. Obviously running too rich now - how do i change that. Checked all nuts etc for tightness to eliminate leaks....not sure what to do next!!!
Spray carb cleaner around your manifold to eliminate any leaks
if your idle increases then that's your leak
In the past I have found leaks in just about every bit that can leak including the bearings on the lower spindles. I bought a set of these for each carb I have refurbed over the years, fixes possible air leaks on those spindles for good, also stops the spindles binding. Carb cleaner is a bit on the flammable side so beware spraying onto hot engine parts. Make sure you have the insulator / spacer plate fitted under the carb.
It would also be worth spending £8 on a endoscope camera to plug into your phone, check the exhaust valve seats for pitting without taking the head off. (you will have to remove the manifold though)
Clean the plugs and run at idle, Put the slow running mixture screw in to one turn, wind the slow running stop in two full turns. Do not use more throttle than needed to get it fired. give it ten minutes, switch off and check the plugs. If it's wet or sooty you may need to get a new mixture screw as they do wear. They also deform the aluminium inside the carb body if overtightened.
Its a primitive engine so think primitive tools. The old gunsons tool for looking down the plug hole to set the mixture works well, gunsons colourtune I think it's called.
Did you write down the numbers on the jets while you were cleaning them?
Its a new carb Ade , however one thing Glenn said struck me as odd , he changed the cambelt because the existing one looked old ,now why would the builder reuse an old cambelt , what else was not changed , the inlet manifold gasket??
WD40 does the same job
An air leak would have more effect when the engine was ticking over (i.e. high vacuum) than when revved and it would lead to whitish plugs (or maybe just one white plug). Glenn has black plugs, so it doesn't sound like an air leak to me.
What happens when the accelerator pump diaphragm splits, does anyone know?
@Glenn: I believe that you took the various jets out to clean them. Did you see any markings or numbers on them? I would imagine that there would be numbers showing what size they are which we could check against the standard spec. I'm thinking that the previous owner might have changed them while trying to get the car running correctly when the problem was actually a blockage.
What happens now if you pull the choke out Glenn?
Thanks for all the replies guys - I am going to do some more digging tonight if the weather holds - as for the jets at the bottom of the float chamber i think they were both marked 140. The car was running pretty well with a big improvement after i cleaned the carb and set the best lean idle. The problems seem to have occurred after i changed the timing belt. When i said it was old i guess it had been on for a while but for less than £10 i got a new one. I'm thinking now it may be one tooth out on the top pulley as it is difficult to see the markings using a mirror and torch although they seem to line up. Anyway let me know what you think and i will report back as soon as i get a chance - thanks all.
I have a Vernier pulley on my Pinto, with a high lift cam, which I run with 6 degrees (crankshaft degrees) of advance. That is supposed to increase the low end torque (by closing the inlet early) but I have never run it any differently so I can't vouch for its effect. Some people with longer duration camshafts run twice that amount.
There are 38 'teeth' on the standard camshaft pulley, so being out by one tooth represents about 9.5 degrees on the camshaft, which would mean 19 degrees on the crankshaft. I would imagine the engine would still run but that it would have quite an effect.