Hi,

The ignition advance should be set at warmed up engine.
1. connect the magnetic pickup of the timing light to the 1st cylinder's high tension lead
2. disconnect the hose from the distributor's vacuum advance chamber
3. loosen the distributor retaining screw
3. the idle RPM must be between 850 and 950
4. use the timing light on the flywheel, adjust the advance knob until the "T" mark is aligned with the arrow
in the observing window
5. read the advance value, it should be between 7 and 9 degrees
6. If the advance value is not within the range above, adjust the distributor housing (clockwise - decreases the basic advance, anticlockwise - increases the advance)
7. repeat from step #3
8. when finished, the distributor retaining screw must be re-tighten. After this check the advance again.
9. reconnect the vacuum hose

 

Also you can check timing at max advance, 4500rpm I think. This might be more important to you that correct timing at idle. Of course the correct timing at idle should also give the correct timing at all revs but old ign systems (particularly dizzy advance springs) mean this may not be the case. I think the "II" mark on the flywheel corresponds to the max advance setting, so with the advance knob on your timing light set to 0 and the engine at 4500rpm the "II" mark should be visible.

 

Ok thanks for that guys. Will try it out today weather permitting.

 

I've read that for unleaded you should retard the advance 3 degrees. Does this mean I should set the advance at about 5 degrees? I'm a bit confused

 

Don't think leaded/unleaded will make any difference - it's the octane rating you need to be aware of. In NZ you can get 91, 95, and 98. Set to factory specs if I run 91 my sprint pings noticeably but with 95 it's fine.

So just make sure you use 95 or higher, assuming the octane rating system is the same in the UK.

 

Unless the petrol has a very low MON rating like mine in Uruguay!
(But not the case in UK, you have access to good quality petrol)

The RON here is 97 but MON is 83!!! So it acts like a 92 RON.
Loads of octane boosters required and less advance.

 

Right, I've checked and adjusted the timing but the car still isn't running very well. Fine on acceleration but when you are cruising it starts to stutter, especially in forth gear for some reason. Any ideas?

 

If this happens around 2000-2200 RPM, the ignition advance may increasing too fast.
You can try to disconnect the vacuum hose from the distributor's vacuum chamber
to see does it make any difference. (plug something into the open end of the disconnected
hose, to block the air entry)

 

If idle is bad too I'd check for a vacuum leak in the inlet

 

think the guys have said already, but it sounds a classic case of dirt in the jets.

take them out and clean them, some carb cleaner and a blast with an air line should sort it

 

Okay, car is now fine at idle, just poor when running, especially at lower speeds. So I'm going to have a good look at the carbs. Sprint is on twin carbs and I think they are webers. Anyone got any advice, like what I should be looking for, is it worth stripping them down? Do I need to remove the carbs or can I access them by just removing the air intakes? Any info and tips would be helpful. Thanks

 

Clean the idle jets. Lift the airbox complete with curved trumpets off the top of the carbs and then you'll see the top of the carbs. The idle jets are 2 of the brass screws in the top of each carb. Unscrew and remove and make sure they're absolutely spotless - brake cleaner/carb cleaner and a blow through with compressed air. Try that first and see how that improves things.

 

Thanks sprint Veloce, I'll give that a go this week and report back.