Setting Points

[whiteclad57]

So, the manual basically expects you to already know how to set breaker points, reasonable for a mechanic in the 70's, not quite so today. I think I've got the gist of it, rotate the flywheel to F-1, adjust baseplate so that point barely cracks open, rotate flywheel to F2 ensuring that points stay opened, then rotate to F3 and F4 ensuring the same with the right(?) side points. Then fine tune to adjust for split timing. What I don't understand is when or how is the proper method for setting the point gap. Do I just eyeball when the point opens widest at the highest point of the cam and adjust to 0.016 from there, or do I adjust at a certain point on the flywheel?

Also I don't have a premade light on hand for doing this, would I be correct in assuming a standard 13v tail light bulb wired to pair of alligator clips would suffice for this?

[Rambozo]

Yes, a tail light with some clips is perfect for that. You can also use a multimeter to measure voltage with the key on, or just use the continuity meter with the key off. The plugs fire when the points open. The coils build their charge while the points are closed.
Yes, put the rubbing block on the highest part of the cam, then set the point gap. At one time there was something called a dwell meter that would let you get the point gap set exactly, by measuring what percentage of rotation the points were closed, but good luck finding one of those anymore. Some multimeters can do duty cycle, and I recall there is a way to convert duty cycle and dwell. Just like you can get the timing pretty close with a test light, but you can get it exact with a timing light. Another tool close to getting lost in antiquity.
Makes me feel old.
I've never done points on a GL1000 but I had a CB750 that I think had the same points setup. You could only change the timing for one set of points, on the baseplate, then rotate the whole plate to move them both. A pretty good system, once you got the hang of it.
Remember to put a light smear of lube on the point cam to keep the wear to a minimum. Does that have a felt pad the rubs lube on the cam?

[whiteclad57]

Alright i spent 3 hours and apparently can't even correctly set the initial gapping, when adjusting at the highest point of the cam lobe I have nearly 3mm of dwell to get rid of, clearly this can't be done without nearly rotating the plate halfway around so obviously I'm doing something wrong. Does anyone have a diagram or picture of how the concentric is supposed to look when adjusting for the left and right points gap?

EDIT: I should have figured; the manual is extremely misleading if the points have ever been replaced about how to set the initial gapping, in this case I had to set both sets, not just the right, using the additional gapping on the points mounting holes without rotating the backing plate. At the very least they are now gapped correctly to start timing, which by the way is near impossible to do with a set of needle leads hooked up to a voltmeter. Update after I make a test light tomorrow. It's rather disappointing how there is not literally a single video out there on how to set the points on these bikes correctly, only a $40 pdf (not knocking it, haven't bought it but the guy who sells it has helped me immensely with his other advice especially regarding the B clutch spacer).

[whiteclad57]

Well, the timing light is just making this even more confusing, setting the gap to 0.16 and aligning the left side points to the F1 marking results in them only staying open until the T1 mark then closing, then reopening nearly perfectly at the F2 mark and closing at T2. To my understanding they are supposed to stay open right until reaching F2 then close at least according to Randakk's split timing article. I'm not exactly sure how to do this I can't shrink the gap to keep the points open until they reach the f2 mark without also causing them to run over, while the second set is firing. Any ideas?

[Rambozo]

The number of people interested in setting points is probably very small. Dwell is measured in degrees so I'm not sure what you mean by 3mm dwell. Changing dwell (point gap) will change the timing. In fact on some engines that is the only adjustment. So, the first thing you do is turn over the engine by hand and set the point gap for each set of points on the highest point of the cam. If you want at this point you can spin the motor with the starter and check them with a dwell meter. Not as accurate as with it running but usually more than good enough. (gap alone is usually good enough). Then you set the timing of 1&2 cylinders by rotating the base plate. Then set the timing of 3&4 cylinders by moving the sub plate. Moving either plate can slightly alter the point gaps, but usually not enough to worry about. Just back the screws off a little so the parts are still snug, and use the provided adjustment places with a flat head screwdriver to pry the points or plates slowly to bring them into spec. I put red lines to show where to adjust the gap and blue lines to show where to adjust the timing with a flat blade. That is what the little bumps and grooves are for.

If you really want things exact, the nice thing about bikes is that you can fine tune the dwell and timing with the engine running. Apart from GM peek-a-boo distributors you can't do that on most other engines.

[whiteclad57]

Perhaps I'm not explaining the problem well enough, I can get the timing for points 3&4 great, no problem. The problem is that the points plate for 1&2 has too large of an opening for the mounting screws, as such if I place it all the way to the left it throws the point all the way over to where I have almost 3 millimeters of it, I f I put it all the way to the right, then I have so little that the points never open. If I try to set it somewhere in the middle, then I have an issue where the top and bottom are not perfectly equal and so my gap intervals are all wrong. The manual offers no answer for this problem, as it is the best I have, is that the 3 and 4 timing are correct, and the 1&2 is mostly correct unfortunately it also firing at T2 causing a weak spark for that side. No turn of the base plate is unfortunately enough to not get it to not fire at T2 while also leaving the dwell correct for T1. I'm at the point where I should probably take it in to be looked at by someone with points experience, however labor prices around here being what they are, it might just be best to switch to a dyna system and have it over with, anybody have experience running a dyna with stock coils compared to the 5ohm dyna coils?

[Rambozo]

Some pictures might help. Are you using a new set of points?

[whiteclad57]

I am using a new set yes, the bike has always run hot ever since I've had a mechanic adjust the points after I rebuilt the carbs, and every part of the cooling system has been replaced or checked, and spark plugs show slightly rich if anything so the ignition timing was the only thing it could still be. The existing points on it were heavily corroded and worn down, probably original to the bikes 38,000 miles. So, I replaced the condenser and the points set.
Just earlier today I took it on a 15-minute drive, and it just confirmed my suspicions, the bike still runs hot and now the idle is 500rpm lower with pretty consistent deceleration backfiring from what sounds to be only on the right-side exhaust. I would give photos but they wouldn't really be of any use.

Left points open at F1 through T1, close, then open again when bike hits F2 and close a bit after T2
Right points open at F2, close at T2.
I'm pretty sure the left points opening at F2 is the main problem here, but it seems no matter what I do I just cause an issue elsewhere for example extending the gap to 0.021 or so will stop the points from opening on F2 but it also causes them to close super early on F1, the only other thing I believe could be causing this is that the rotating cam on the advancer is scored and slightly pitted.

[Rambozo]

The timing would have to be massively retarded to make it run hot. And a good cooling system should still be able to control it. Measure the dwell and timing for each coil with the engine running. The points cam could be reground back in the day, but finding a shop that can do that will be a hard task. Some antique car shops still have the old distributor equipment.
It sounds like you might be better off taking it to an expert. Or devote some time to learning about this. Also, you need to say what you are looking for when this is over. I have done restorations where the customer wants it exactly as it came from the factory, and others where they want it more reliable and are not opposed to upgrades like electronic ignition. On a bike this old many things will be in poor condition even if they haven't failed completely. Due to the fact that many replacement parts are no longer available, some parts will require uneconomical repairs. This is fine for a restoration, but not practical for just a rider.

[whiteclad57]

Yeah, I'm getting the feeling here that just installing a dyna system would be best here. I don't know what else could cause such high temps though if it isn't the timing. it has a brand-new radiator with additional fins over stock, new hoses, replacement oem thermostat, I've ensured that none of the engine passages are plugged, oil is clean and changed, the return mesh is clean, fan comes on slightly early if anything. The plugs tell me it isn't running lean, likewise the working fuel gauge says it isn't a 7v regulator issue. I guess it could just be a bad temp sending unit, but the fact it blew a head gasket last year makes me think it isn't. I did buy an IR laser thermometer to check if it is actually overheating, which I will check in an hour or so, I'm assuming standard op temp is 210 Fahrenheit based on what's shown in the manual.
Also, I realize "take it to an expert" is generally good advice, however that the last time I did that, I got screwed, hard, and ended up paying close to two grand for the equivalent of a jury-rigged tuneup on a bike that needed so much more and most of what was done I had to redo properly later. So, I'm reluctant to do it unless I'm actually completely out of options which unfortunately I seem to be.

[Rambozo]

No matter the timing, the cooling system should be able to deal with it. Measure the water temp going into and out of the radiator. Many so-called "improved" radiators do not work as well as the OEM. Many bikes have borderline cooling systems, that have had special tweaks from the factory to run at acceptable temps. More fins, means less airflow, so it may not be capable of shedding the heat without a more powerful fan to go with the higher fin count. The days of good copper and brass radiators are long past. However, there are plenty of custom aluminum radiator makers out there that should be able to handle this. Because of the differences between copper and aluminum, the aluminum unit will probably need to be larger to get the same performance.

[whiteclad57]

Well, I measured the temp at the end of another 10 minute or so ride. The dash thermometer was right at the last third of the white area around 205-215F or so. readings on the top of the block near the sending unit itself were around 170-180F, while readings near the sight glass were closer to 200F, a reading taken at the rad fins was right around 168F. I don't know enough to know if this means the unit is accurate and internal temps are higher from the lack of exposure to the ambient air, or if the unit itself is failing and temps are actually a good 20-35 degrees cooler than its showing. I'll take another measurement at the rad intake and outtakes tomorrow to rule out the rad 100%. I'd test the sending unit itself but the manuals method for doing so just makes it seem easier to replace it.

Just to be clear, if the lower end of the operating gauge is 85c and the upper end is 110c, then the middle should be 97.5c or right around 208f correct, and unless the bike is for example loaded to max capacity and lugged up a grade should not exceed that temperature during normal riding?

Also, in regard to the points this is what I was referring to, the holes in it that the mounting screws to the base plate secure to are about 1.5mm larger than the diameter than the screws themselves so there's is free play in either side that leads to an exaggeratedly large or small point gap that can't be adjusted out by just rotating the base plate depending on where it is secured down, you can see in this case that there are multiple indents around the mounting holes from where previous owners I'm assuming had to move them to get them centered. I've had no such luck getting them centered myself.

[Rambozo]

The pivot post of the points should protrude out the back and fit into a matching hole in the breaker plate. The oversize screw holes are normal as they need clearance to let the points pivot. It sounds like your points or plate might be damaged. I was unaware that you can no longer get new points from Honda. That really sucks as the old Honda tuneup kits came with a whole replacement breaker plate with both sets of points and new wiring with a heat sleeve and all new screws. If the points are just flopping around the screws, you will likely never get them set properly.
Here is a pic where you can see where the posts should locate in each plate.1 2 on the lower plate and 3 4 on the upper.

There are used ones on ebay, but beware, from some of the photos you can see some are missing parts.

When riding at speed, the temp should hover around the thermostat set point of 82°C as I recall. When stopped it will climb to the fan set point of 100°C as there is no airflow through the radiator without the fans. The fans should cycle on and off to hold that point. This is also the case when riding slowly or stop and go.

[whiteclad57]

The worst part about working on a thrashed-out bike with no experience of how a proper one should be is I can't tell what's wrong and what's just a idiosyncrasy standard to a 45-year-old machine.
So, to clarify since I've replaced the points completely, should the initial gap on the left side points be made using the extra room around the mounting screws, not by rotating the base plate? Since this is what I have been doing. I don't believe the plate itself is damaged, although all the screw heads were stripped and missing washers, so I had replaced them with equivalently size Allen heads.
Yeah, the points I have are aftermarket although I made sure that there is little side to side play in them and the swing arm is free of looseness, in other words they are as close to acceptable as I could get without paying for NOS.

[Rambozo]

Rotating the base plate should not be changing the maximum point gap at all. If it is, something is wrong. Only check the point gap when the rubbing block is on the top of the cam lobe. Turn the engine by hand until this is the case. Forget the timing marks when setting the point gap. Look at the cam and make sure the points are at their maximum gap, then measure and adjust that set of points. Make sure the points are located on the plates and only move by rotating around their pivot point. Run the yellow screws down lightly until the points no longer can be moved with your fingers, but are not fully tightened. Insert a large flat blade screwdriver where the yellow X is. Align with one line of the X and rotate the screwdriver to pry the points open or closed as needed to set the gap. One line of the X pries them open the other pries them closed. This can even be done with the engine running using a dwell meter. Then lock down those yellow screws. Rotate the engine to move the cam to the other set of points and repeat.
Next set the timing of the number one cylinder by rotating the entire breaker plate. The best way to do this is with the engine running using a timing light. Static setting with a test light using the timing marks will be close enough if that's all you have. Lastly set the timing for cylinder 3 by moving the sub plate using the green screws and the flat blade much like setting the points.

This is a wasted spark system so there are more sparks per revolution than your typical 4 stroke, but it is also split into two by the dual points and coils. So, proper setting on ignition test equipment would be a 2 stroke two cylinder. Since that isn't common, you can use a dwell meter set for 8 cyl cars and it should read 22.5 degrees. For timing lights that show degrees, it really needs to have a setting for two stroke, or you will have to double the readings. You could also use the Honda T marks or a degree wheel. I always added paint marks to my Hondas so I didn't have to use the plastic window thing to see the timing marks without blowing oil everywhere. You can put a TDC marker on anything that spins at crank or cam speed.

[Rednaxs60]

To further the timing light issue, have had to learn about this for a wasted spark engine. Any timing light will work. If you have an older timing light with a degree dial, set it to "0" and leave it there, don't use the degree dial. My timing light is my Father's older Snap-On MT241T.

I have found the engine timing port on the 1200 to be a PITA engine started or stopped. I fashioned an engine case timing mark pointer and installed it above the left side timing belt:

I am upgrading my '85 FI model ECU and have installed a 36-1 crank trigger wheel and use the teeth on the trigger wheel for degree increments. One tooth is 3mm wide and is equivalent to 5 degrees of timing. One valley between each tooth is 3 mm and equivalent to 5 degrees of timing. I would recommend the use of a thin, stiff 75 mm plate sandwiched between the crank timing bely pulleys as a degree wheel - make sure it cannot move. I mention 75 mm because every 3 mm of circumference is equivalent to 5 degrees of timing.

Install the engine pointer and timing degree wheel, set the engine at #1 TDC, mark the degree wheel at the pointer as "0" degrees. Mark the degree wheel with 6 to 10 - 3 mm marks both ways. This allows you to check max timing advance that is at approximately 3000 RPM.

Just a few thoughts on points and timing. I remember the old days in my Father's garage.

[Riccardo3257]

Did you resolve these issues? I’m having difficulty with my ignition timing on my ‘75. I’m pretty sure everything else is okay so I suspect ignition timing. One thing I have noticed is that the manual states that when the timing mark F-1 aligns the dot on the breaker cam should be in line with the rubbing block of the points for number 1&2 cylinders but mine isn’t. It aligns with the rubbing block for 3&4 cylinders