[Ice]

 My intent is to get a programmer if Br. thump wants to part with his power arc and compare it to mine. Since Chumma has a programmer already he can borrow my power arc for establishing some baselines for comparisons if he'd like.

[1 Thump]

My intent is to get a programmer if Br. thump wants to part with his power arc and compare it to mine. Since Chumma has a programmer already he can borrow my power arc for establishing some baselines for comparisons if he'd like.

Ice: Mine is the older non programmable version.

[Ice]

 Crap 

 There still has to be a way to hack into it. The factory programmed it somehow.

[solg]

My intent is to get a programmer if Br. thump wants to part with his power arc and compare it to mine. Since Chumma has a programmer already he can borrow my power arc for establishing some baselines for comparisons if he'd like.

Unfortunately the Power Arcs are write only.

[ace.cafe]

The hardest part is getting an ACCURATE TDC  index. You have to split the dwell period, and it really needs a degree wheel to do it, unless you have the timing chest open. Just trying to eyeball it could leave you up to 20 degrees off.

If you need to retard the whole curve slightly, then just set the index to 2 or 3 degrees ATDC instead of TDC and every part of the curve will then be 2 or 3 degrees retarded. If you need advance,  the do the same idea in the BTDC direction. Ya gotta get resourceful to get what you want, if you can't get into the program.

[solg]

I haven't been setting TDC with a timing wheel. I have been using a .01mm Starrett dial indicator being careful to take up the gear lash were I set TDC.Using a timing wheel seems a bit messy with having to remove the primary cover and all. But, if it offers more accuracy perhaps I should give it a try. My thinking is that I must be getting pretty close my way because after switching back to points ,and using the aforementioned procedure,the bike usually starts on the 1st kick. (As long as I have the choke set match the ambient air temp.)

[ace.cafe]

The piston dwells at TDC for almost 20 degrees.
You could easily be several degrees either side of TDC without knowing it, unless you split the dwell.

[solg]

Understood. I will use a timing disc next time.
But, excactly how do you get to TDC with a timing. Disc? I have read Hitchcocks tech note on the subject but , to me it seem to be missing a step.

[ace.cafe]

Understood. I will use a timing disc next time.
But, excactly how do you get to TDC with a timing. Disc? I have read Hitchcocks tech note on the subject but , to me it seem to be missing a step.

I will have to describe it when I get home from work. I had to take a local store job because Enfield business isn't happening.

[solg]

Sorry to hear that!

[tooseevee]

Understood. I will use a timing disc next time.
But, excactly how do you get to TDC with a timing. Disc? I have read Hitchcocks tech note on the subject but , to me it seem to be missing a step.

           You find TDC with a dowel in the plug hole or a TDC Finder tool (Google It).

            Then you fasten a piece of wire to a solid place on the engine; a screw or a bolt.

             Then you put your degree wheel on loose and bend the wire to point at the graduations.

             Then you turn the degree wheel to where your pointy wire points to 0 degrees. (Everything has to have a point. Right ?  )

              Secure the degree wheel.

               You now have a degree wheel fastened to the crankshaft. Turn the engine one way from 0 and you have degrees before TDC. Turn it the other way and you have after TDC.

                I hope that isn't clear as mud  The zero doesn't have to be at North (Up). 

[solg]

Thanks, that much I understand. That doesn't nessisarily bring you to the center of the dwell though.Does it?

[tooseevee]

Thanks, that much I understand. That doesn't nessisarily bring you to the center of the dwell though.Does it?

               I've never much dwelled much on dwell 

               I've always set my bikes' timing static at full advance. I've never used a light. I just count on getting my points gap set very accurately and then I time the ignition with the points cam at full advance and the crank set on the Full Advance mark.

[ace.cafe]

123

[Arizoni]

solg

To answer your question, " That doesn't necessarily bring you to the center of the dwell though.Does it?", the answer is no.

The movement of the piston when the crankshaft is between + or - 10° is almost unnoticeable unless a dial indicator with its tip is placed against the top of the piston.

To get a better estimate of where the real TDC actually is, with the timing disk installed, the crankshaft needs to be rotated up to the point that the piston first seems to stop and note the rotation reading on the disk using the pointer as a reference.

Then, rotate the crankshaft a bit more until the piston just starts to move downward.  Take another reading of the angle on the disk.
Calculate the number that is half way between the two disk readings and then rotate the crankshaft around until that number is aligned with the pointer. 
Then, re-zero the timing disk. 
Doing this should set the disk very close to the right  place.
Of course using a dial indicator will get a much more accurate reading but the improvement isn't really worth the expense of buying a dial indicator (unless you have some extra money just sitting around).

After doing this, don't forget to rotate the crank to get the TDC at the top of the compression stroke to set the timing.