The Triumph Dolomite Club - Discussion Forum

The Sprint is finally idling very sweetly but once I put the engine under load, it starts chugging, as if a plug has gone dead. Idling back it's ok but won't take up speed.

ideas?

It's due for a head recondition and timing chain replacement.

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1972 Spitfire MK IV
1972 Stag
1980 Sprint

1962 Land Rover Series 2a
1961 Land Rover Series 2a (under restoration)
1983 Land Rover Series 3

1995 Suzuki Samurai SJ413

1972 MGB GT (banished for being too tight to fit in it)

Oil in dashpots or lead or plug breaking down? Insufficient points gap or duff condensor....you name it, it could be loads of things.

Change one thing at a time....

Jonners

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Note from Admin: sadly Jon passed away in February 2018 but his humour and wealth of knowledge will be fondly remembered by all. RIP Jonners.

Fuel starvation

Paul

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hmm - that's interesting.

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1972 Spitfire MK IV
1972 Stag
1980 Sprint

1962 Land Rover Series 2a
1961 Land Rover Series 2a (under restoration)
1983 Land Rover Series 3

1995 Suzuki Samurai SJ413

1972 MGB GT (banished for being too tight to fit in it)

Mario

Check the bottom of the float bowls for dirt / debris etc - this could reduce the quantity of fuel going to the jets, whilst on tick over its fine but when more fuel is requires it could be resticting the flow - assuming you have SU carbs.

Paul

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Could this be the reason? The SU manual says that the gap should be 0.125 but it's more like 3/8 inches. The other one is only slighter better. No adjustment is possible so it seems that the wrong valve/float has been fitted.

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1972 Spitfire MK IV
1972 Stag
1980 Sprint

1962 Land Rover Series 2a
1961 Land Rover Series 2a (under restoration)
1983 Land Rover Series 3

1995 Suzuki Samurai SJ413

1972 MGB GT (banished for being too tight to fit in it)

Problem solved - PO fitted a washer which, once removed, let the float higher in the chamber. Will check whether this makes a difference to the 'chugging'

_________________
1972 Spitfire MK IV
1972 Stag
1980 Sprint

1962 Land Rover Series 2a
1961 Land Rover Series 2a (under restoration)
1983 Land Rover Series 3

1995 Suzuki Samurai SJ413

1972 MGB GT (banished for being too tight to fit in it)

That angle is not good of your float. The base has to be level or a tiny bit going up. I do sand a fiber washer to size to have the correct angle. Also the floatneedles come in sizes. A sprint does need the larger size. There are many parts in su's that look identical but are not and are easily mixed up.

Jeroen

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Classic Kabelboom Company. For all your wiring needs. http://www.classickabelboomcompany.com

Had the Sprint sent to a mechanic friend as I could not solve the severe tapping issue that it had. Within 30 minutes he phoned and said that problem solved - a shim had fallen out and led to the tapping noise! How the hell could that happen (the shim falling out I mean)? It never occurred to me to have a look around the cylinder head.

_________________
1972 Spitfire MK IV
1972 Stag
1980 Sprint

1962 Land Rover Series 2a
1961 Land Rover Series 2a (under restoration)
1983 Land Rover Series 3

1995 Suzuki Samurai SJ413

1972 MGB GT (banished for being too tight to fit in it)