Even tried starter fluid through the carbs...no pop. Plugs fire on the bench but they sure don't seem to
be delivering when installed.
ET: Engine (Twin) Still Can't Start My Twin, Replaced Mag, But Not A Pop
- Thread starter CarlHungness
- Start date
be delivering when installed.
That 4 degrees is one huge difference from what I've done previously. Years back I made a piston stop at 39 degrees, and for this go-round I screwed the end bolt so I got 35 degrees. I set it at the 35, open the ears of the ATD wedge them open with hand carved wooded piece (with a wire through it in case I drop it). I then set the points to J-u-s-t opening (can tell with my light connected to center bolt HOLE with center bolt removed..can tell
when the light goes off..the 'shoe' on the cam ring is on the bottom, as it has always been, I have a pencil mark
there..and just as light goes off, I install the ATD ever-so-carefully. I take out the earth brush, install a 5/16 bolt
to hold the armature (finger tight), check point position, screw on the ATD, tap the outer washer at its pins,
then tighten. Then I replace center bolt in points, check to see if the light goes off at 35 degrees..all done on
#1 cylinder. This Lucas has been timed that way time and again. Spark on bench is good. Will get a helper
to see if plugs are firing in-situ, can't kick it and hold the #1 plug at the same time. First time for everything, first
time in over 30 years of installing the Lucas, then B-TH it isn't starting. I dis-connected the kill button wire, thought
it might be shorting out. Fun problem this one.
Thanks, I am at 35-36 this time. Previous years with the Lucas and B-TH I had 39 degrees. I re-set the bolt
in my piston stop.
Approximately how long would one make the piston stop for bottom dead centre. I could mess about for half an hour trying to figure that out. I'd be using an old spark plug, gutted with an adjustable center bolt.
You might just have given us a clue. For easy starting one needs to have the points opening at about 4 deg BTDC, In the olden days with normal fuel one needed a a fully advanced figure of about 38 - 39 BTDC fully advanced, The movement on the ATD was designed to take the timing from 39 back to 4, i.e. a range of about 35 degrees. If you have the timing at 35 fully advance now that give a timing of about zero degrees fully retarded. That is retarded for easy starting. Could that be your problem? If so the it is only a matter of cutting down the range of the ATD.
You are saying 'cutting down the range of the ATD' and I am not in synch with the statement enough to know
what to do. Are you saying time it at 4 degrees?
Yes. Four degrees BTDC fully retarded. That is do not push out the weights in the ATD. Let them stay in their fully home position. This will probably mean that when on the road with modern fuel you might get some pinking ( squeaky noise, I am not sure what you call it over there) but at least you will know that the bike goes. Then you can think about cutting down the range of movement of the ATD mechanism and that is another subject.
Well at least you are being specific enough. I've never installed the ATD without pushing the weights out but I respect the opinion and will give it a go tomorrow. I still wonder just what the hell has changed. I'm going from 35 degrees down to four! That's an incredible amount. At this point though, it seems as though my years of study haven't served me very well in knowing how to install my sparking device. I've never encountered such a prickly problem. "Cutting down the range of the ATD" is a foreign statement to me, so I require some knowledge here too.
Will post my results.
your deco' lever isn't hanging up?, surely you'd notice and still get the odd attempt at ignition. I'd be looking at the dry plugs as initial concern.
As sure as eggs is eggs this is going to be a numpty one when it comes to light.
As sure as eggs is eggs this is going to be a numpty one when it comes to light.
With the ATD off the bike you could try measuring its range (by sitting it on a timing disk with a piece of wire as a pointer for example). The range would need to be 15.5 degrees if you want 4 to 35 on the timing. If it is 17.5 you will have 0 to 35 making it harder to start (although I would think it might still fire at least).