Morris Minor Owners Club

having caved and bought yet another hif38 carb, as my other one was not working at all, i got this new one working but its running the engine very rough. it is also running rather fast, i have reduced the throttle adjustment screw so its actually not doing anything and when i reduce the mixutre, it does reduce the revs.
however, if i stop the engine and restart the engine, i have to use full throttle to start then i can reduce it almost immediately.
so, how can i get the carb set up right, so it runs well and i can start it on the key every time (like i could do with the standard carb)

Is the choke on all the time maybe

nope, when the choke is pushed in, its off at the carb

to lean maybe

not sure, it runs ok without the choke, i just have to use the choke to get it going then i can knock it off straight away

You certainly have your adventures Chris! I really don't know what to say - I bolted mine on - started the engine - twiddled the screws slightly - and it's been perfect ever since! Look for air leaks - is the dizzy vacuum pipe connected - is the rocker cover breather connected to the brass inlet on the side of the carb ?

yep all connected up correctly. ill go back and check for air leaks and then i am scratching my head. i followed the haynes su carb book and reset it all, but that just maid the carb do nothing. i did fettle with the screws and it works, but alas not fantastically.
ill have a fiddle abit more then report back i think

Usual Qs - does the piston rise/fall easily? What needle is in the carb - and is there some 3 in 1 oil in the damper chamber ?

Yes the float moves freely, its got a AAA needle in it, and 3 in 1 in the damper. So all is well on that part.

Take it for a good run - then look at the plugs and report back colour.

Most well-used SU carbs will be worn around the throttle spindle, allowing air in. This allows them to run with the throttle butterfly fully closed....

Not so much the HIF - it's return spring is on the shaft - so not the side loading of the earlier carbs on the spindle. Unusual to get any significant leakage there.

well i got the carb running sort of.
it still takes full choke to start and then i can pop it straight back in a few seconds later. However, once its started it runs at a nice idle speed but once i set off and have to stop again (junction, traffic lights etc) the engine revs are very high, even though nothing is sticking.
so what could be causing both these abnormalities?

Air leak at the manifold/head joint or manifold/carb joint or do you have a servo intake with a leaking pipe or leaking servo ??

strangely, whilst "crossword" was picking up the 8inch brakes, a bloke who has a mini and also a marine engineer said almost the same thing.
so ill go have a fettle with the gaskets, pipes and anything else seal related and hopefully that should fix it

Well it MUST be sucking air somewhere - otherwise it CANNOT run!

Chris ,
The other random thought that occurred to me whilst travelling back , I recall from somewhere , either here or Mr. Vizards book that the HIF38 & 44 carbs prefer the dashpot piston to be vertical & i believe there is an adaptor available for the inline engine that makes the angle correct . I think the Metro transverse engine is at an angle that makes HIF carb pistons vertical . Might be worth trying .

Regards Andy .

That's a new one on me......... Any of mine have/are at an angle and work just fine.

Ditto - had a pair of HIFs on a Rover V8 that were both at an angle.... from the factory.

Exactly....... the beauty of the HIF is that it CAN work at an angle !!!!!!!!!!