cu hall ignition distributor

[njv]

hi
a while back it was noticed that the hall sender fully elecronic dizzy has funky characteristics inbuilt in it this is a post ive cut and pasted here from the stf t4rum about what i have done to remove a little bit of the funk to the cu dizzy fitted to my typ4 engine to anybody on a budjet i think this makes a good dizzy choice for a typ4 engine an even better one with the modification and the vaccume hooked up from each carb results are excellent and once youve got it set up you need never touch it again

hi
i while back now in november it was posted that the electronic hall unit distributers had the ignition retarded to the no3 cylinder this was achived by the size of the slots cut into the beam breaker disk .

stock as follows
cyinder no 1 12.7mm gap
cylinder no2 13.8mm gap
cylinder no3 11.4mm gap!
cylinder no4 13.7mm gap

i have removed this disk and opened up all 4 slots to 13.8mm and what a difference it has made firstly i have gained 150rpm at idle the distributer was not removed to carry out this operation only the disk was removed from it so the distributer body has not been turned in any way!!

the engine is smoother throughout the rev range it is as if a slight imbalance has been removed that to be honest i never even noticed was there .

jake allways refered to these distributers as funky and yes id agree well ive got rid of the funkyness all 4 cylinders are now on the same advance curve fairly painless.

heres how it is not to difficult the worst bit by far is getting the disk out of the distributer first suggestion would be put a couple of drops of your favorite penertrating oil on there for a couple of days before you attempt it remove the circlip and with two wide blade flat screw drivers levering against the side of the distributer lift the disk up and of with a pair of twezers remove the small locating pin that holds the disk to the shaft put it somewhere real safe now!

ok in a nice safe enviroment with a set of small files and some real good tin snips equally open up each of the 3 smaller holes out two 13.8mm remove equal metal from both sides of the slots i trusted myself with tin snips on the number three slot or i would have been there all day
.

i have measured and measured and as far as i can tell the slots although smaller are still equally spaced around the disk if anybody else can observe otherwise please let me know

ok reinstallation in time hornoured is the reversal of removal couple of drops fom an oil can on your felt if you havent done it for ages fire it up away you go totally non funky full advance to all 4 cylinders .

once its warmed up and all you should obviously check timeing as you have altered the gap slightly on no1 by.5 of a mm on each side ive checked mine and im actually not going to touch it as it has given me a little moe advance at idle without in anyway affecting total at 3500rpm but i do need to turn my idle back down to 950 rpm from 100rpm

now this opens up the question what happens if i open them all up to lets say 14.5mm ie another .25mm shaved of the side of each slot?

now at the end of the day ive messed with something the factory did to try and limit some damage they new exactlly where they were setting the timeing for each single cylinder now on anotherwise stock egine these variables in timeing from cylinder to cylinder are probably not really noticable start bumping up compression and things need to be spot on timeing in each cylinder so your engine makes equal power

i hope this may be of interest to some off you out there running this type of dizzy

next one i need to do is get all 4 throats from my dells hooked up for vaccume instead of just the one on each side this should smooth it out just that touch further

happy holidays.