Timing adjustment at limits

[Greg65]

Ok boys and girls advice please.

The timing adjustment on my bike has always been on limits, ie I am now at the point where I can no longer rotate the face plate clockwise any more. Up until now I have set timing by use of multimeter but have splashed out on a strobe unit. This shows me requiring further adjustment, which is not possible. I have stripped, checked the auto advance and reset the contact gap to 0.35. What am I missing or is the cam on part number 196 out of limits? Suggestions please.

Cheers,
Greg

[K2-K6]

Take the advance and retard mech off the crank,  now spin the motor to see if the spindle is bent at all.  If it's out it'll give you timing setup error.

Also the min points gap is 0.3 mm if you set the 1and4 pionts at that it should force you to rotate the whole plate anticlockwise (just trying to visualise that)   the gap reduction should retard the timing and cause you to compensate by moving the plate.

Obviously finish by setting the 2and3 points to match.

[Greg65]

Thanks, Ive set it to 0.35. Will do as you suggest and check for true. Also would the part of the points that rides the cam wear significantly?

Thanks,
Greg

[K2-K6]

If the points heel that rides the cam wears, it's compensated for by adjustments to the points gap and not the timing.  So you'd eventually find them not able to open the points far enough to make the gap you want. It wouldn't generally give the problem you are getting.

The gap you set will change the timing though.  It's no detriment to set them at the lowest end of spec as it has the effect of increasing the dwell time on the system.  This is the amount of time the points are closed and so charging the coils until the spark is required. Some view this dwell as more critical to performance than setting them to an absolute gap.

[Greg65]

Thanks K2, quick check of understanding. By lowest end of spec do you mean smallest gap ie 0.30 or the largest at 0.4?

Greg

[K2-K6]

Yes the 0.3 mm should retard the timing a little and reduce the need to rotate the plate clockwise.

That should give you a bit more room to get it correctly matching the correct timing position.

[TrickyMicky]

I suffered the very same problem a couple of years ago, and discovered it was caused by the pattern backplate I had purchased. The purchase was made because I needed new points, and rather than fiddle about fitting these it seemed a simpler idea to buy a fully fitted unit, wire it in, time it, and Bingo, job done! After much head scratching it transpired  that there was not enough length to the adjustment slots which led to there being a compromised setting between cylinders 1/4 & 2/3. Having kept the original backplate, new item was returned to DS and exchanged with 2 sets of OE points with no problem. Fitted new points to old plate, and happiness and serenity was restored. Michael.

[Greg65]

K2. Thanks ,reduced to 0.3 and on limits. As far as I can tell the spindle is not bent. Nice weather, might have to do an extended test. Oh dear.

Tricky. Checked my back plate, the only marks are Tec. Is this an original plate or an after market?

Thanks,
Greg

Edit for SP and extra info.

[K2-K6]

TEC is an original supplier to Honda of that era,  so if there's a problem you'd have to compare it to another to see if any obvious discrepancy present.

If you can get the timing now with points gap at smallest but within spec then it shouldn't be a concern.

Smallest gap would only give you concern perhaps if the condenser is not working well.  Gap should only close up if heal material wears, but light oil on the little felt pad should largely prevent that.  I'd not see it as any problem at low-ish mileages.

[mattsz]

An old thread, but since Greg65 didn't follow up to say whether he solved his problem, I thought I'd continue rather than start a new one...

I set the points gaps - the 2-3 points gap adjustment screw was so tight, I didn't stand a chance of loosening it without stripping the head.  I drilled it and used a torx bit to extract it, gotta get a new screw! There's a lot of that going around on this bike...

Anyway, I found the points plate to be roughly in the middle of its adjustment range - but both sets of points opened with the F mark almost a centimeter from the "matching mark."  In order to get the 1-4 points to open right at the F mark, I had to rotate the points plate clockwise as far as it would go, until it bumped to a stop.  As it happens, this position set the static timing perfectly.  2-3 ended up very close too, just a minor adjustment to bring it into line.

So... does this seem appropriate?  Presumably the bike was running well last time it was used a few years ago - is it possible that the static timing marks would be so far off to make the bike run well?

Final position of plate (sorry, the pic is rotated 90º CCW for some reason):

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Marks:

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[Deano400]

Yes the 0.3 mm should retard the timing a little and reduce the need to rotate the plate clockwise.

That should give you a bit more room to get it correctly matching the correct timing position.

Do as K2-K6 says. I had the same problem and all was resolved by setting the points gap to 0.3 mm.