Topic: Cold header pipe # 1 cylinder - eventually kicks in

[DaveBarbier]

Hmm. Testing the coils as per the link I posted and 0.01 is the only reading I can get from each coil.  All wires disconnected from the harness.  These are stock coils.  I'm a long way off 4 ohms.  If I have such weak spark, how does it even run?

If you're getting that reading on both coils when your only complaint is 1/4 and 2/3 is firing fine then you must be testing it wrong.

Snap a clear picture of the coils, meter with leads and the wires you're connecting to all in one picture if you can.

[b1jackson]

I did the repair job on the two wires before I did the meter readings.  There was also a slightly bare wire on one of the black/white wires connecting the coil to the harness so I fixed that too.
I forgot to mention that my plugs are all new and NGKR DR7EA

[Deltarider]

http://blacksquaremotorcycle.com/ignition-coils-test/

Using this as my guide

Thanks for the link. It's an excellent guide and can be used for those to come. In defense of Clymer I must say that ohmmeters in the early 70s were not as cheap as they are now.
When I reread, I see that you have both 5KΩ sparkplugcaps and R(esistor) sparkplugs that are usually around 5KΩ as well. Even if that was OEM for Canada models, it's a bit much. Most of us prefer either 5KΩ sparkplugcaps or R(esistor) sparkplugs. I'm not saying this is the cause of the problem, but all in all you have a bit much resistance there. With everything else OK, it will run however. The problem is that these resistors have the nasty habit to increase in resistance over time and then you'll have little or no margin left. My advice would be to run the normal D7EA plugs when you have the 5KΩ caps. For the moment you can use what you have and check carefully if there's any 'firing' between caps and head (= ground) or HT leads and ground. Best seen in the dark and listen for little cracklike sounds. On the other hand four NGK D7EA plugs is not a big investment and you could help us if you tested both sets and communicate the results. After all there is the chance the #1 sparkplug is no good anymore and simply replacing could be the cure. Mind you, we're still in step 1 of trying to analyze what is possibly wrong. BTW, I recommend to use the Honda plug wrench that is probably in your toolset. I've made it a habit everytime I replace a sparkplug to put a tiny little bit of coppergrease on its thread (Not all needs to be covered. Far from it).

[b1jackson]

[/quote]

Snap a clear picture of the coils, meter with leads and the wires you're connecting to all in one picture if you can.
[/quote]

[calj737]

The black probe from your meter is connected where? It should be connected to the BLK/WHT wire of the coil you are measuring.

[b1jackson]

Yes, it is.  My black probe is busted so I just have to make connection with the wire tip.

[calj737]

Is the BLK/WHT wire just above your hand the wire you're testing with the black probe?

[b1jackson]

Yes

[DaveBarbier]

Above the yellow wire and to the left of the green wire, is that a solid white wire or a black/white wire?

So you're touching the yellow wire and the black/white wire with the meter leads. Ok. What is your meter set to in the ohms scale? The picture isn't very clear.

Do you have any known resistors laying around that you can test and confirm the meter is correct? But you tested the plug caps and got good results...

[b1jackson]

Above the yellow wire and to the left of the green wire, is that a solid white wire or a black/white wire? Thats from the other coil I believe.

So you're touching the yellow wire and the black/white wire with the meter leads. Ok. What is your meter set to in the ohms scale? The picture isn't very clear. 20 ohms. Same as when I did the plug caps

Do you have any known resistors laying around that you can test and confirm the meter is correct? But you tested the plug caps and got good results...yes, meter is fine

[Deltarider]

Just figured out your's must be a K3. Now I know, I have some more advice but first things first.

[b1jackson]

Ok.  Here is an update.  A weird one...but an update anyway.

I hooked all the coil wires back up and swapped in new plugs in 1&4 (same kind as what was in it).

Before I hooked the fuel tank back up, I decided to bump the starter and run it abit. Fired right up and # 1 pipe warmed up right away #2 stayed cold, and 3&4 were warm.  So I swapped in a new plug in number 2 and trimmed back the spark wire abit.  Then reinstalled the tank thinking I was in the clear.

Backed it out and ran it about 5 min.  #1 dead cold and all others hot.  What?  Frigs sake.  I think that I am going to trim back the spark plug wires abit and see if that isn't the issue.  Perhaps with a weakening old coil, it doesn't take too much to prevent a full spark where the wire goes into the boot.  Blasted carb cleaner into the line to before the tank went on.

FURTHER UPDATE - wires all trimmed back now and caps retreaded back on.  Ran it again and same thing..cold #1 header all other perfectly hot.  Pulled #1 plug and then cranked it.  Lots of spark and it ran briefly on three cylinders with one plug removed and spark running through me. bzzzzzzz. Haha.

[b1jackson]

Tomorrow's job will be to try a valve adjustment.

[Deltarider]

If you haven't done that before, maybe it's wise to have somebody attend that has experience.
BTW, still haven't read that you checked for arcing between plugcaps/HT leads and enginehead when everything is in it's place. Best observed in the dark

[b1jackson]

Yes. I did check last night looking in the dark and could not see any arcing anywhere. 

Regarding a valve adjustment, is it possible that one cylinder could be so far out of adjustment that it won't even fire while all others work and perform perfectly?  I know I have to check them all but it seems strange that I'm still having problems with only one cylinder and I know it's capable of firing because the pipe #1 was hot as per post 36 above.

[Deltarider]

Yes. I did check last night looking in the dark and could not see any arcing anywhere. 

Regarding a valve adjustment, is it possible that one cylinder could be so far out of adjustment that it won't even fire while all others work and perform perfectly?  I know I have to check them all but it seems strange that I'm still having problems with only one cylinder and I know it's capable of firing because the pipe #1 was hot as per post 36 above.

I do not think it has to do with the valves because it wouldn't explain the 'kick in'. But maybe it is a good opportunity to exercise a valve gap check. When you do it for the first time, I always advice to have somebody attending that knows how to do it and can check what you've done.
But I'd rather start with a simple test to see you have the correct fuel level in the bowls and fuel flow is constant and not intermittent. Are your fuellines OK, without kinks and without 'extra' filters? Reason I ask is that decades ago I had this 'kick in' effect and it was caused by an extra inline fuelfilter. K3 carbs sometimes have their vent tubes blocked or pinched closed by the main stand. These are all simple tests that won't take much time and you have to do them anyway. If you mistrust coil 1+4, you could swap it  with coil 2+3 and see if problem follows the move. Hope leads will be long enough. Coils rarely go bad but if they can't get rid of their energy for a too long period they will.

[b1jackson]

I talked myself out of a valve check with the fear of messing something up.  I have done them before but with a simple 1 cylinder scooter engine bench.  Somewhat easier.  I did pull the valve caps for a look and put the engine at TDC.  Sliding in the feeler, I see no need to adjust as I have good drag on the gauge.  I'm tend to agree that valves are not the issue since I have had fire in this cylinder before.

I checked the pilot screw on carb number 1 since it's reasonably accessible without yanking the carbs.  I turned it flush with 1.5 turns.  Then took it out and blasted a good dose of carb cleaner into the carb.  When I put it back in, I turned it out 2.5 turns from flush as I read somewhere that that is a safe starting point.

I do have a small clear inline filter which isn't clogged.  I need the filter as my tank is a bit cruddy inside. 

I'm just going to let it since for an hour or so before buttoning things back up and seeing if the pilot screw clean and tweak did anything.

[Deltarider]

I checked the pilot screw on carb number 1 since it's reasonably accessible without yanking the carbs.  I turned it flush with 1.5 turns.  Then took it out and blasted a good dose of carb cleaner into the carb.  When I put it back in, I turned it out 2.5 turns from flush as I read somewhere that that is a safe starting point.

Are the minuscule rings still there?

I do have a small clear inline filter which isn't clogged.  I need the filter as my tank is a bit cruddy inside.

  As long as there's a good filter on the petcock, no extra filters are needed and they can cause the fuel flow to become erratic.

[b1jackson]

Yeh, there is no filter on the petcock. 

I did notice rings but they may have stayed in the carb.  Maybe I am incorrect in calling this the pilot?  It's the needle looking bit with a spring that is under the carb closest to the engine.

[Deltarider]

Yes and it should be set as prescribed. There should be a small O-ring.

[b1jackson]

I'm losing ground now! : .

Put it back together and fires righ up.  Kept hand on the throttle for about 2 min or so and now #1 and #2 are cold.

WTF is with this sporadic cylinder fire?  Can't wait to hear how good it sounds when all 4 are firing!

[calj737]

So why not do the simple thing and replace your points and condensers? You've spent a great deal of time on coils and carbs, but I see nowhere that you've dealt with or mentioned servicing or confirming the ignition.

[b1jackson]

I guess that is where I should move to next then.

[calj737]

You should have confirmed this long before actually. It was encouraged on the first page, within the very first replies (3k Service).

All you've done is valuable too, but, intermittent spark at the coils is very symptomatic of bad condensers (or faulty points). A clear shot of your ignition plate please.

[b1jackson]