17 replies to this topic

[HarrysMini]

3-in-1 is way too thin.
 
Like others have said, drain it out and refill with engine oil.

3in1 is SAE20, which is what the genuine oil supplied by SU is. If it's causing problems and you need to use 20w50, your carb is worn out or you're using the wrong spring.

[Vipernoir]

Brand new HS4s (definitely not worn out), HIF38s, HIF44s, twin HS2 and assorted other carbs I've played with all produce a better throttle response with 20w50 than 3-in-1.
The HIF38 on Tubbs was tried with different springs, needles and dampers to no avail.  Changed the oil and it was fine...

[Ginge620]

 

I'd check your ignition timing and also that your vac advance is connected and undamaged. Mine had terrible flat spots despite a nice blue burn on colour tune, a quick fiddle by ear of the timing and instant pickup. Mine is adanced more now than specified but doesn't pink and much better than running on book figures.
 
don't forget that quoted figures are probably for lower octane fuels so that will make a small differance

How did you time the engine by ear?
 

turn the dizzy slowly listening to the engine speed, when it is at its fastest clamp the dizzy and readjust the idle speed on the carb

With or without the vac tube on?