running rich

Post by **napper62** » Sun Jun 18, 2006 8:59 pm

Hello all, my 1970 1098 is running rich, and I had a mechanic look at it the other day. He told me that the carb is worn and there is 'no further adjustment available'.

Any advice ? Do I need a complete new carb ? Or what ?

Any help would be very gratefully received.

Cheers,

Napper.

Post by **minor_hickup** » Sun Jun 18, 2006 9:09 pm

You need a service kit, available from East Sussex Minors and I'm sure from most other Minor places. The important bit is the new jet, which will have ovalled allowing too much fuel past the needle. The guy who rebuilt mine advised changing the needle as well. I'm not sure if it was necassary, but he said you may as well to get it running on top form.

Post by **napper62** » Sun Jun 18, 2006 9:18 pm

Thanks a lot, I shall do both.

Post by **minor_hickup** » Sun Jun 18, 2006 9:29 pm

Hang on! I think they do a rebuild and service kit. I'm not sure if the service kit has the jet assembly and cannot access the site for some reason. If it does thats the one!

Post by **napper62** » Sun Jun 18, 2006 9:36 pm

Ok, thanks for letting me know what I need, i'll contact a few suppliers.
Cheers.

Post by **Packedup** » Sun Jun 18, 2006 10:01 pm

Could be the spindle holes are worn - They can be redrilled and bushed at a price, but it's probably cheaper to find a good s/h carb.

If you feel like making a small modification to the car get a manifold that allows a HiF to be fitted, the spindle/ holes seem to wear much less on them (probably because the return spring is on the end of the spindle/ carb body, pullnig round rather than down) and they're not at all bad for a bit more flow/ economy

Post by **Welung666** » Sun Jun 18, 2006 11:38 pm

If you need a second hand carb I have a few

Lee

Post by **bmcecosse** » Mon Jun 19, 2006 1:26 pm

But worn spindles just affect the idle mix - making it a bit weak. Granted - some then adjust for this, which can make it run rich all through the range. There is always adjustment on the carb - may mean re-setting the needle. Does the 'mechanic' really know about SU carbs ?? Why do you think it's running rich ? Usual reason is blocked air filter - or choke mech not going home properly. Don't rush to buy a new carb - or even a service kit - till you know what's really going on.

Post by **minor_hickup** » Mon Jun 19, 2006 2:27 pm

Surely you should be able to see if the jet has ovalled? I know mine had and you could see clearly upon inspection. I had the same problem as napper, the jet was wound up as weak as possible and it was still thumping away at idle.

BM, spoke to the chappy who rebuilt my carb a minute ago, (a mates dad) and he said my needle was ever so slightly bent, which is why he replaced it.

Post by **bmcecosse** » Mon Jun 19, 2006 10:53 pm

Ah - bent needle - very nasty !! If the jet is right up - it's possible to set the needle down very slightly in the piston - but I agree, if the jet is worn oval - then get a new one. I assume it was worn by your bent needle !! Although throttle spindle wear is not ideal - it's not that big a problem - but the later HIF (horizontal itegral float) carbs are very much better - no surging or spluttering on corners for one thing!