9 replies to this topic

[DAC1952]

Starts without issue and revs lovely however when you get her out and up to about 20mph she starts to judder / bog down quite violently. Playing with the choke does help things but it’s short lived. However, sometimes if you turn it off and back on it drives like a new car.

998cc engine with mini spares stage 1 kit.
All new points, dizzy, plugs, leads etc. HIF4 - seems ok. Compression consistent in all 4 pots. Dashpot oil exists and is fresh as is oil. Timing seems ok. Idles fine.
Replaced plugs as was sooting up.
Have been getting some grey smoke from air breather.
New head gaskets and all other gaskets too. New rad etc. essentially, most parts are new!

Banging my head against a wall.
Had been sat for a number of years. 

Any suggestions welcome. Thanks in advance.

Edited by DAC1952, 03 February 2025 - 02:08 PM.

[bpirie1000]

Manifold gasket all tight? No air leaks? Usual ways to find one (if there is one)

Also think the mixture may need a tweak!!

With the choke improving it suggests too lean. If no improvement with choke then poss too rich.

Edited by bpirie1000, 02 February 2025 - 08:45 PM.

[68+86auto]

Do not touch the carb until the ignition system is proven to be perfect.

Is the condenser loose?

[DAC1952]

Checked condenser, seems ok. Checked this morning for leaks using the wd40 method around the manifold gaskets but no change in engine tone. 

Drove her this morning and was horrific until going down hill and managed to hit 50 and then she opened up and was bang on. 

[Chris1275gt]

For very little money I’d change the condenser to rule it out.

[andyapanel]

Have you checked the float bowl for rubbish? I used to get little flakes in there before I fitted a fuel filter.
Good luck.

[andyapanel]

Have you checked the float bowl for rubbish? I used to get little flakes in there before I fitted a fuel filter.
Good luck.

[Lplus]

What kind of fuel pump is used?  This sounds like intermittent fuel starvation to me.

[babsbrown]

Have you gapped the new plugs to the right gap?

I know its noddy but can easily be missed.

[coopertaz]

sounds like points closed up or condensor breaking down