Flywheel fit and electrics

[TMofCumbria]

I bought a 199A. It would not start when I went to collect it but owner said he had had it started to check it was OK that morning. No spark, but when we removed the plug but it did look as if it had run. Got it home cleaned the points and checked gap whch as correct. There was now a spark but may be not as bright or as consistent as it should be. Still no start although I think it fired a few times. Tested the HT coil and secondary winding was open circuit so bought new coil from Inmotion. Slightly better spark but still no start. Had the condenser checked by an electrician. No Mf capacitance so ordered one from Inmotion which has just arrived.

When removing the flywheel the nut was not very tight, only 30 to 40 ft lbs, it should be 75 ft lbs. However the flywheel was very difficult to pull off, I had to use an impact wrench on the puller bolt. When I got it off I found there were slivers of metal on the tapers and dents and areas galled out. The key and keyway are in good condition. Because of the lumps and dents the flywheel would not go back on properly, and could be rocked about. I removed most of the high spots with a die grinder and am now lapping the flywheel onto the taper, just about got it satisfactory. When the flywheel is fully seated how far should the threads on the crankshaft stick out beyond the flywheel?

Obviously the flywheel not being seated as far back as it should be and possibly not concentric on the crankshaft, will have reduced the magnetic flux in the source coil so I am hoping properly seating flywheel along with new capacitor fixes the problem. Does anyone know what the resistance of the source coil should be and who can rewind them? (please dont suggest electronic ignition, I am wanting just to get the bike running and everything else checked before I spend a lot)

The timing was 2.9 mm BTDC. However to achieve this the stator plate was in the fully retarded position, which seems unusal. I have had bultacos many years ago and think the stator was usually near middle position. Unfortunately I did not clock the flywheel before removing it and it may have been running out of round due to the shards of metal in the taper. If this was the case it would affect the timing. Where would anyone expect the stator position to be?

Thanks

Tony

[stevem75]

It sounds to me you have a very firm grasp of what’s going on and how to repair and set the ignition on this bike. 
you’ve covered the basics well.  New condenser is a great start.  I’d be suspect that you needed to replace the ignition coil as the original femsa coils rarely if ever require replacement.  However it’s a base covered so good on you for replacing.  The timing issue as you mentioned…. The stator plate was fully retarded ( this would mean all the way counter clockwise).  We see this sometimes with the points that are available on the market today.  The rubbing blocks on the points are of inferior material and wear exceedingly quickly.  Often times so much so that the points won’t open enough or at all. So look at your points carefully to see that the block has ample material on it.  Make sure the points themselves are clean and free of any oil or dust or debris.  Use a fine file or sandpaper to clean. And remember to remove any sanding debris.  You’ve lapped the flywheel taper.  When fitting the flywheel have the points cam lobe aways from the points as it will allow the flywheel to slip more easily into place.  The end of the crankshaft should just protrude a little further or flush with the flywheel itself.  
Once in place set your point gap first.  16 thou is spec.  Once set then adjust the timing by turning the stator plate advanced or retarded to get the correct timing.   You’ll need a dial gauge in the bore for this step.  Try not to make adjustments to the timing with the point gap.  Verify too that your plug cap is in good working order.  And obviously use a new plug.  NGK BP5ES is the correct plug.  However non resistor plugs are becoming harder and harder to find so you may have to settle for a BPR5ES.   The points systems usually give good blueish yellow spark.  This is plenty.  If you’ve got spark move on to fuel.  A clogged pilot jet or clogged enrichner tube on the bings and Amals can give problems with cold starts. And finally compression. Primary and secondary compression is important.  Primary being engine case compression secondary being top end piston compression. These bike are notorious for needing regular crank seal replacement.   Step by step keep up the process and I’m sure you’ll suss out the issue 

Steve