5 replies to this topic

[64mini]

Hi all, i have a slight problem when coming to a stop. The revs sometimes just drop away and it wants to stall. Bit of heel and toe is my normal fix. Its done this since the engine was rebuilt. Its a 1380, modified head, 286 cam with twin hs4. I understand the idle will never be great but just trying to get it to run as smooth as it can. Idle is set to around 1100 and runs fine when driving/accelerating and while running in the garage (not under load). Plugs look ok, maybe a bit rich. Aaa needles, su carb oil and red springs. Would different oil or blue springs change the way it returns to idle? No vacuum leaks that i can find. No rolling road anywhere near me here in oz! thank you

[cal844]

Try a slightly heavier oil, it's a bit of experimentation!

Make sure the piston spring is fitted in the dashpot of the carb.

[Spider]

Check the Fuel level in the Float Bowls. It may not be this, but worth checking.

The Carbs may also be fitted with the wrong type of Damper, one that offers damping on acceleration but next to no damping on dashpot piston fall.

[Matpaul]

Distributor with faulty / worn advance mechanism? i.e not returning to the same idle advance. I had the same problem some time ago and like you used to feather the throttle to keep it going. CSI distributor fixed it.

[andyapanel]

If you lived in England, I would suggest cleaning the carb and ensuring the piston can move easily.

Where you live, do you ever suffer fuel vapourising? Its just a thought, but I have relatives where you live and they like to inflict photos of interminably hot sunny days on me. 

Good luck

[64mini]

Thanks for the replies. I live on the gold coast. Very hot today. There are worse places to live! The distributor is being replaced very soon. My budget can't stretch for a csi unit so had to go with C-27H7699 from mini spares. Should arrive this week.
I've checked float levels. All ok. I check with a 1/8 drill bit between the top of the float and bottom rim on the float lid. If you know of a better way let me know.
The different dampers seem interesting. Im running auc8114. The new twin hs4 sets come with 8114 according to ms diagram. I assume that would be the correct one? I have a spare set of auc 8103. The carbs are originally off a 71 mgb from memory. There are several different dampers but i cant seem to find what the affects of the different dampers will give?
As for fuel vaporizing, its possible. The carbs seem to get very warm indeed. I've got a heat shield and exhaust wrap but i have thought about phenolic spacers? Any thoughts on these spider?
I'll try different oils and the other dampers i have this weekend and report back. Thanks again