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HIF Questions

Posted: Sat Jan 21, 2012 4:43 pm
by welshrat
I have recently picked up a HIF carb and inlet manifold, never had anything to do with them in the past so hoping someone can answer a few questions for me. I believe it is a 38 rather than a 44, diameter of carb opening minifold side is 1 1/2 inch, am I right in thinking the 44 is 1 3/4. Can anyone let me know what conects to what on the picture (1 to 6). Also any info on choke/accellerater cable fiiting would be very helpful. Thank you[frame]Image[/frame][frame]Image[/frame]

Re: HIF Questions

Posted: Sat Jan 21, 2012 4:54 pm
by bmcecosse
Hmm -5 looks like fuel in and 6 possibly a feed back to tank. 4 is breather and 3 is the intake for sucking fumes away from the crankcase. 2 is vacuum advance connection to dizzy - and 1 must be a connection for a silly vacuum gauge ! I would just plug 6 and 1 and see how it goes. It's possible that 6 and 1 are a 'part throttle' weakening device which I think was used on later models.

Re: HIF Questions

Posted: Sat Jan 21, 2012 5:55 pm
by linearaudio
Quite right, BMC! Number 6 should connect to number 1 with a length of black rubber pipe. It is the "part load weakening" device fitted to later HIF's. If when you run the engine up you find it hesitant when you are cruising, then it will be down to this,either 1/4 turn of the mixture screw to richen overall(somewhat defeating the object!) or disable it, by blocking both ports 1 & 6.
I find mine fine in summer conditions(hence my staggeringly good fuel economy :) ), but this time of year I had to richen slightly. Probably might have got away with angling the air filter intake towards the exhaust manifold, but hey-ho!