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Poor running after speed


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Hi, Went on a drive to visit someone last night.  Car seems to be running OK.  Went past a lorry so hammered it a bit and the engine began to falter.  Engine appeared to be running and i dont believe I was one pot down based on sound and relative smoothness of engine.  Got to the point where I could barely move. As soon as I lifted the clutch the engine dropped off and no power.  Got to a safe place,  stopped the engine, restarted after only 30 seconds and was fine. Continued journey and drove home probably totaling a further 25 miles or so with no issue but did remain at about 50 mph.  

Had a suggestion that possibly the fuel regulator is playing up and over fueling the carbs.  As speed increases it allows additional fuel but doesnt cut back as I slow down but then recovers if I stop.  Looking at the exhaust it appears to be running a bit rich but any other suggestions?

Much appreciated.

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Glad it was a simple fix. Fingers crossed it's solved. Had been following this as I have a stutter when putting the foot down from 2000 rpm, clears up by 2500 and beautiful after that, but as I d

How do mean Jon. Incorrectly mounted.  you mean where its bolted to the inlet manifold.  There are alluminium spacers and large O rings.  All been renewed by me but checked by GST

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The O rings are there to absorb the engine vibrations which would shake the carbs & cause the fuel in the float chambers to froth, causing irregular high speed running if the mounting nuts have be over tightened, over compressing the O rings. Only people that don't know this over tighten them so I'm sure it's not your problem. Good luck finding the solution. :thumbup: 

Cheers,

John W

http://jonwatkins.co.uk

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I had a few similar issues before my fuel pump died.

It was working but in the end didnt have enough power to lift the fuel, so you could hear it running but was just old and gutless.

Our pumps have to work quite hard to maintain enough pressure and they are quite pricey too but you have to have the correct one to supply the pressure required.

 

buddsy

 

"Belief is the enemy of knowing" - Crrow777

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Well gone back to it today as have been away. Found excess cable on the choke where it connects to the carbs was catching on the plenum chamber section that sits over the top of the carbs. That was the excess revs and small amount of popping while idle. Didnt have time for a run but am hoping that may have fixed the other issue. Choke was on all the time. 

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Glad it was a simple fix. Fingers crossed it's solved.

Had been following this as I have a stutter when putting the foot down from 2000 rpm, clears up by 2500 and beautiful after that, but as I don't have the choke connected your solution doesn't solve my problem :) 

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@NigelM that'll be most likely changeover from the idle jet to the main jet

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One day I suddenly had an issue that I couldn't pull away from a petrol station unless I really revved the engine over 2500 rpm. Was advised that I might have water on the carb (not a technical term) and that I should just heat soak the engine to get rid of it by running up to temp on the drive until the fans cut in, let this happen a couple of times and it would go away. Did this, and it cured it.

 

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