Topic: Setting points timing - help

[Greyhound]

So I’m trying to reset static timing on a 77 CB550K using a circuit tester.

I have the needle point grounded to one of the screw holes which holds the points cover on, and the clip on the bolt to the yellow wire.

When I slowly creep the kickstarter with my hand until I get to T F 1-2, the circuit tester never lights up, even if I go all the way around 360 degrees, it never lights up.

What am I doing wrong??

[kawabunga]

Do you have the key turned on? Killswitch set to run?

[Buddhapie]

You need to have juice going to the points.


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[Deltarider]

Looking closely at 1+4 breaker in the picture... could it be some metal 'lip' is accidentely contacting the plate?

[Deltarider]

Ooops, sorry, I misinterpreted your picture. I need glasses. Anyway, check the breakerpoints small bolt doesn't short to plate. Sometimes the forked terminal touches the plate accidentely.

[brewsky]

Did you observe the points actually open visually?

[Greyhound]

Yupp kill switch set to run and ignition turned on.

Yes the points open/close, the bike starts and runs, I just want to perfect the timing since it hasn’t been set in a long while, and I will be installing a Hondaman ignition, so I’d like the timing to be perfect.

[Deltarider]

So... what was the cause?

[Buddhapie]

If you want the timing perfect then use a timing light. Also im wandering if your circuit tester is faulty or you didnt have it grounded, if the bike runs it should definitely light up.


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[Greyhound]

Still trying to figure it out. Circuit tester is brand new.

Indeed timing light would be best, but I don’t have one. Although I’m not against getting a light to do it that way, I’d like to figure this out to know what is happening.

[brewsky]

Does the circuit tester light up when you use it across the battery terminals?

Do you have a multimeter?

[PeWe]

It is sometimes easier to redo and do it right instead of investigating what you have done wrong.

Hondachopper has several tech tips.

http://www.hondachopper.com/garage/garage.html

Ignition:
http://www.hondachopper.com/garage/carb_info/timing/timing1.html

Read this too, important to make sure the plate sit tight.
https://motorcycleproject.com/text/sohcign.html

This is another
http://forums.sohc4.net/index.php/topic,147444.msg1678696.html#msg1678696

Plus Hondaman's hint of cutting the advancer springs 1/2 wound.

It take some experience to make points to work really fine.
Just read and do.

[Bodi]

Since the bike runs, the problem is with your measurement technique.
It is odd to connect the test light the way you have. Normally I would connect the clip to ground and poke to test for voltage with the light's pointy probe tip. Set a point contact definitely open - gap visibly open - and probe around it. With key and kill on there must be battery voltage across the contacts on an engine that would start if kicked over.
With an old filament bulb test light either polarity works but I have used a low voltage probe with LED that only lights with tip positive.
And be a bit careful, even with an excellent condenser a voltage pulse from the coil appears across the points when they open... not enough to hurt you but gives a decent jolt.

[Keith]

Seriously, I would invest in a decent dwell meter and a timing light. That is the best, most accurate method. You can also check your advance with a timing light.

[kawabunga]

I will echo the suggestion of buying a timing light. You think you're close with static timing until you check it with the light. They're great to have.

[Greyhound]

Thanks a lot for the assistance. I already have a multimeter, but haven’t tried it on timing. I’ve ordered a timing light.

However, I somehow thought that static timing would be tighter than with a light, since you can precisely adjust the point to the exact place where the plug fires... How does a light make this process more precise than that?

[scunny]

The timing light tells you where the spark occurs at full advance, which is where you will be riding.
static is at idle.
You still haven't said if the light you are using works when connected straight to the battery ?

[PeWe]

The strobe light will measure the real result when everything moves.
These electric parts  will act differently at 1000 ---> rpm than when measure by just turning crank by hand.

Same with measure point gaps with a dwell meter which will give you the reality.

Setting gaps and ignition statically is just the start point to make engine to start. The rest is to adjust when it idles at around 1200 rpm.
Verify full advance at around 2500-2700 rpm.
Important to not forget checking 2:3.
I usually verify cyl 4 (1:4) and 3 (2:3) with ignition strobe lamp clamp sensor on HT leads.
 
You need to recheck and adjust again, dwell, ignition strobe lamp, adjust dwell again and maybe ignition 1:4, 2:3 again and again........

Dwell meter will make it possible to adjust it to run very evenly.
I'm sure many have tried to synch their carbs when the real problem was not equally adjusted points. I guess it is possible to set one point at its highest gap 0.4mm. Adjust the other when engine is idling until engine runs best by ear.

The Dwell meter will show you the numbers so you will see how to adjust.

It will be easier if points are close to highest gap. It is  common that it is not possible to move 1:4 plate or 2:3 plate enough clockwise when it enter bottom of the slits. Clockwise - retard (later), counterclockwise - advance (earlier).

My K2 had points at max gap, not possible to retard enough for correct setting at idle.
Dwell at 8 cyl setting 23-24.5*. (Max to min gap)
I set to around 23.3 since it differs warm vs cold.

I cut both advancer springs 1/2 wound so the advancer will not advance too early.
This made it possible to get ignition correct at idle. 1:4 /2:3 F lines up with case mark at idle and full advance at 2600-2700 rpm.

I prefer 1200 rpm idle to ensure oil pressure when really warm and easier city riding with not that abrupt stop in low speeds at throttle offs .

It is possible to make it to work really fine with points.

One thing that will make you crazy entering a never ending adjusting loop is if the point plate sit loose and can move sideways when the 3 bolts are not tightened.

The 3 embosses on crank cases need the to be hammered upon to swell so plate can not move sideways the slightest.

If it can move sideways, it will move either side horisontal or up- down when adjusting 1:4 ignition. This will change point gap which will make it to run uneven. Smaller gap advance, larger retard.

This is probably the reason why people gave up points, installed Dyna or similar electronic point free ignition instead that will not change ignition setting if plate slides sideways a little.

I guess this is different on different cases. My CB750 K6 really needed to be adjusted. Sharp metal hammer and hammer straight to the embosses with plate in place, not tightened bolts. A little on each at the time so all 3 will swell equal. Not hammer from the side to risk cracking them.

My CB750 -72 cases also needed adjustments.

My latest CB750 -75 engine build has cases where plate sit tight and nice.

Engine will not run better with ignition max advanced. Risk for pinging, holes in pistons and lower power.

I tested on dyno a few years ago. My ignition was adjusted properly, maybe goal to not let it be retarded.

I turned plate around 2mm on its outer edge compared with embosses in cases, marked with a marker pen.

Advanced it a little , less hp, retarded gave +2 hp compared with initial setting. The hp was in the 90whp area.

It is possible to adjust it to get perfect ignition at idle AND full advance.

Do not give up and set ignition wrong by only adjust at full advance and get a rattling crappy idle with bad behavior at take offs until reaching 2500rpm. Easy to get it really nice if you know how.

My K6 had such sloppy springs so full advance happened before 2000 rpm. Not before 2500 on a CB750.

[Greyhound]

Works!

Thanks a lot to everyone who chimed in. I tried reconnecting the circuit tester by grounding it to the engine and using the needle tip to touch the wire screws for each side, this was after I charged/tended the battery (which was way low).

Runs much better. I’ve ordered a timing light to refine the timing once it’s running as well.

One question... Which notch on the crank should line up on the notch on the bike? The left one or the right one?

Or should the single notch line up directly between the two notches?

[seanbarney41]

I disagree with much of this.  I often time a bike statically to get it running, and then check with timing light and its right where I set it statically.  Also, unless something is wrong with your advancer, it's gonna advance right to the ll.

[Greyhound]

Okay are you saying that setting timing statically is suffice?

[Deltarider]

It all starts with checking the breakerpoints gap. Normally that's the only thing that changes over time causing the timing to go of. So normally readjusting the breakerpoints gap is enough to correct the timing. You can do it statically using a feeler gauge (0,3-0,4mm) when points are positioned at their maximum opening or dynamically using a dwell meter. Aim at 24,5^o-23^o when 8 cylinder scale is dialed. Statically the yellow 'F' mark should align with the mark in the crankcase.

[seanbarney41]

Okay are you saying that setting timing statically is suffice?

yes

[bryanj]

Must be, i spent years in UK dealerships and never used a strobe

[PeWe]

But it is convenient to see how it works and advancing.
Not expensive tool either. Wrong ignition, too advanced can be expensive.

https://www.ebay.co.uk/itm/200634411103
I have this one, shipping was much lower when I ordered.

Similar from USA too