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MG Midget and Sprite Technical - HIF44, a couple of questions

Hi, I picked up a HIF44 at a car show at the weekend for the princely sum of £5 and I'm 95% sure that I have the right one, but I have a couple of questions.

I have scoured the archives but I cant find definate answers:

I'm missing a couple of parts on the throttle spindle, in pics I have seen of HIF's they have a return spring either side of the spindle, The carb I picked up (no ID tag) doesn't have a threaded end on the pipe side (vent, vacuum, fuel) of the spindle so would it be OK to run with just 1 return spring on the other side?

Also when the choke spindle is rotated should there be any movement on the jet as on HS2's as they choke pulley seems that it will only give an increased idle where it makes contact with the throttle pulley.

Last but not least when the throttle disc is fully open it has approx 1mm side to side play but fits snug when closed, is this normal and will fitting the throttle pulley/spring tighten this up, or do I need a new spindle?

Thanks in advance.

Mark
Mark Whitmore

pics of mine:-
http://www.eatworms.org.uk/album/album2.php?album=midget-HIF44&mode=page&index=12
Dean Smith ('73 RWA)

Thanks for the pics Dean, I'm sure I've looked through those during my delve into the archives but still very helpful and thorough!!!

Done a bit more research on a couple of mini forums and it seems that the earlier hif carbs only had the spindle threaded on one side so that should be ok.

Can someone advise on the 1mm side to side play on the spindle when open and the choke/jet question.

Thanks
Mark
Mark Whitmore

Mark, I had to wind the springs up pretty tight to get a smooth return on mine once the throttle cable was fitted. Dean - doesn't yours have that spiral pulley as a throttle lever? I thought they all did.

The only drawback I can think of is if you want to enter competitions. The scrutineers will expect one more return spring than you have carburettors (i.e. 2).

What happens inside the integral float chamber when you open the throttle is a mystery to me, but someone will be along in a minute.
Nick

No - mine has a simple crank rather than the "snail". It was from an Ital. I had a HIF38 that came with my titan and that had the snail. I was going to nick it but in the end the HIF went to a mini (998) owning friend.

It did mean I could simply drill a new hole in the crank to both :-
a) reduce the pedal movement required (and get full throttle)
b) provide less leverage and make a stiffer thottle pedal. It was much lighter initially on the HIF than the old twins.
Dean Smith ('73 RWA)

Thanks for the info so far.

Just one last question for Dean:

I am looking to use the same K and N filter and I would like the logo to be level as well (I'm funny about these things!)

What did you use to block the original 'post' holes that are used to connect to the front plate to the rear?

Thanks
Mark
Mark Whitmore

Mark - just a couple of well fitting grommets I had. From an assortment pack I bought ages ago so just lucky they were a good tight fit.
Dean Smith ('73 RWA)

My "second" spring...


Steve Clark

close up - for the static end of the spring, I fabricated a wee metal bracket with a nole, fitted under one of the float cover securing screws....


Steve Clark

Note that if you 'Vizardise' the carb by thinning out the throttle spindle that it is a good idea to remove the outboard spring as it will twist the spindle. I've been running with only one spring for over a year now with no problems.
Steve Church

but don't forget a scrute will insist on 2 springs for any type of motorsport
David (davidDOTsmithAT stonesDOTcom)

This thread was discussed between 22/06/2009 and 02/07/2009

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.