hi there ive got an old and poorly Anzani unitwin in need of some help!!
There is no spark, but there is - or at least was some life in her yet! there was enough juice to give me an electric shock, but not enough to make a spark - any one got any ideas??
does it need a new coil - can i even still get one??
HELP!!! (i get the feeling i'm a bit out of my league!! im a tinkerer - not a thinker!!)
If you have a tingle then coils (there are two of em) are probably OK.
Do usual service under flywheel, points gap and clean and check for corrosion anywhere with terminals and grounding. Gap is 0.020.
Parts may still be traceable . Wipac Series 1149Z.
Plugs 0.022 Champion L10 (L85C or L90C)
16:1 mix
Any resistance in HT wires through, replace.
Is it 10 or 15hp?
Amal or Zenith Carb?
They are great machines.
Post a Pic of It if you can.
Regards
C.I.
Last edited by Collector Inspector on Wed Dec 03, 2008 11:12 am, edited 1 time in total.
Unitwins never managed to excite me.
You don't see many nowadays, havn't been offered one for several years.
Didn't everyone's view change when they transmogrified it into the Class A & B racers, the story has it that the Americans would not santion it's use as a petrol powered race engine due to it's ability to whoop the home grown Mercury, so only achohol versions in the US.
There is a petrol one in the Science Meuseum London, carrying a label that says it was the first outboard motor to exceed 100 MPH.
I have one, just got to reasemble the gear driven magneto & sort the exhausts, I don't think the neighbours would be too impressed with a 340cc race motor with megaphones barking at them.
Collector Inspector, you say the usual under flywheel service - but how do i get flywheel off?
I can and have removed the rip-cord bit and loosened the bolt on top (with much grunting!!) but the flywheel dont wanna budge!
If you bend the thread at the base above the taper on the crankshaft, proper tightening again is not efficiently achieved.
Copious amounts of CRC or better penetrating fluid. I prefer inox. Then put it all back together as it was and leave it alone for a couple of days.
OK
Slacken flywheel nut until its flange exerts some reasonable pressure against starter plate but not enough to bend, buckle the plate or strip the threads of the retaining screws.
Tap nut sharply with 1lb hammer. If nothing happens after two goes, more CRC and wait awhile. Keep the force from the nut in play the whole time.
Patience and it will loosen with no damage at all.
I can not believe that someone on this site would ever suggest using a puller.
The starter plate is that the bit with the pully thing - highly technical terms here!! - for the starter chord... of so,
shouldnt the starter plate be removed, i can see no advantage to it being left on when clubbing the thing with a hammer??
All the Super singles that I have dismantled have a self pulling system , just like Villiers industrial engines.
I must admit I've never had a Unitwin apart , if it is a self puller , you will de irrepairable damage using the hammer method.
Does the flywheel nut come right off , or does it loosen , and then after around three quarters of a turn tighten up again.
further to twostrokenut's comment, the nut comes off completely, and hence my confusion at the advice posted by collector inspector. I will post photos later tonight if i can work out how to do it.
the nut was likely not the original then as it was just a standard Hex nut, does that mean i am going to need a flywheel puller after all?
i does look like the rope sheave is original at least it has the anzani logo in the top, although it is fastened to the top of the flywheel by three screws (which look to be about 50 year old so may be the original fixingsd)
Hmm, if it is a standard type nut it will not do the deed old son. The original nut has two flats which were probably rounded off over the years. There is a ring under the cover on the bottom of the nut.
Be very careful and as others have said "Best Of Luck"
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