Help? Mini misfiring and not accelerating

[lewi123]

Hi, im having trouble getting my 998 mini city 1988 running.

The engine starts and ticks over fine and will accelerate if throttle is opened slowly with some misfire but when throttle is opened fast it just boggs down splutters terribly. With the air filter off, if i half cover the air intake the problem seems to be almost resolved.

1. Its running a SU HS carb, piston rises and drops freely
2. Has had new condenser
3. Timing is set
4. Points cleaned and adjusted
5. Leads and plugs all seem to be fine

Would appreciate any help??

[guru_1071]

check the oil in the dashpot, sound like there is none, so the pistion is shooting up and over fueling.

[nick1275]

i had this, was a faulty new condenser. im not saying this is the cause of your issue but might be worth looking at

[lewi123]

Thanks for your help, fixed the problem by going from one extreme to the other by replacing the thin stuff out of the carb dashpot with thicker ep90 gear oil.