No spark. Buggered coils?

[dentedvw]

Let me preface this once again by saying that I am learning as I go. This is my first motorcycle, and I don't even know anyone with a working bike. I have a clymer manual, but there is only so much that one can learn from this. For example, it doesn't tell me that when your two cylinder honda sounds like a harley, one cylinder is not firing.
So I get a bit down a road before I realize that the reason it's a bit sluggish is not that the carbs aren't just right, it's that one cylinder isn't firing. One exhaust pipe not hot, and only mildly warm air coming out of the end. Pulled plug to be sure, yup, no sparks. Got home and checked oil. Ayup, its pretty gassed up. Still, it moved down the road, not fast mind you, but I got around a bit. Now, the only reason I know to check these things is that I asked a friend who used to have a bike. He says it's probably the coil, and I am inclined to agree, but then again... what do I know. I can see that the condenser looks pretty new.
If it looks like a duck... right?
71 CL350
Thoughts? Get new coils? Good place to get one?

My apologies for posting so many questions, but I don't know anyone with a working bike, so the internet is pretty much it for me.

While I am at it, I need either a petcock, or new rubber bits for the valve, also the brass nozzles occasionally fall out.
Gas cap is ziptied together as well.
Might as well get all this stuff in one box if I can. Recommend a good place to find some of these parts?

 

[dentedvw]

I found this tonight over at AllExperts.com, by Bill Silver. it seems like he knows what he is talking about. I am going to copy it here, because you never know when this stuff will disappear. I guess I will have a crack at it tomorrow.
http://en.allexperts.com/q/Motorcycle-Repair-837/1971-Honda-CB350-Twin.htm

The most common problem with having no spark is that the points are dirty and not making good contact. Get a small point file or some fine emery cloth to scrub the faces of the points clean. Be sure that there is no grit left behind to keep them from closing fully. Use some contact cleaner to be sure. The maximum gap of the points should be .012-.014" fully opened on the point cam. The point cam should be lubricated, as well. Generally, I suggest that the point plate be removed (put a scratch mark at the edge so you can get it back close to where it was), so you can inspect the spark advancer, making sure that it is allowed to fully advance and retard w/o assistance. If it is sticking, the retaining bolt/washer has to be removed from the end of the camshaft and the mechanism disassembled, cleaned and lightly lubricated with lithium grease or point grease if you can find it at auto parts stores now. BE SURE to mark the point cam before you slide it off the end of the advancer, as it will go back TWO ways and one will not allow the engine to run.
Once that is done properly, put a LIGHT coat of point cam grease on the point cam, reinstall the point plate where it was marked and then check the point gaps. After that, with the bike on the center stand, you have to remove the dyno cover...put a pan underneath the engine because there is oil inside. Use a wrench to turn the engine over slowly and watch the points open and close. With either a 12v test light or volt meter, turn the ignition on and watch when the points open and close. The meter or light should show this clearly. IF you get differences from one side to the other, then the points are still not closing OR the condenser has failed on one side. Generally, the side with a bad condenser will ARC heavily when you turn it over and the point faces will have HEAVY pitting. The condenser pack is up with the coils under the fuel tank. They are packaged 2:1 so you have to replace the pair of them together. Check ebay for some cheap ones, as HONDA wants a stupid amount of money for them. Or check m/c salvage yards.
The points will open at the F and LF marks when properly set. Do the left side first, moving the point plate to adjust the point opening time. If the right points do not have a separate base adjustment, then you can open/close the point set slightly to change the point open time. Once the timing is set properly, then you should have a good sparkk on both plugs. Use new ones to test, as old fouled ones that will short out internally it it will appear that you have no spark still. The spark plug caps can also go bad, so unscrew them from the wire end and check the resistance with an ohm meter. If they are close to each other... around 5-10K ohms, then replace the caps.
You can leave the point cover off when the engine is running and watch the points for arcing issues.
When you put the dyno cover back on recheck the oil level to be sure that it isn't too low after the cover was removed.

 

[dentedvw]

This is cheap at JCW. Would it work?
http://www.jcwhitney.com/autoparts/Product/tf-VehicleBrowse/s-10101/Pr-p_Product.CATENTRY_ID:2005149/p-2005149/N-111+1971+200730434+600001798/c-10111#BVQAWidgetID

Chrome-plated Ignition Coil, for 2-cylinder 12-volt Motorcycles that require a double ignition lead ZX013085X $32.99

 

[chrisf]

I found this tonight over at AllExperts.com, by Bill Silver. it seems like he knows what he is talking about. I am going to copy it here, because you never know when this stuff will disappear. I guess I will have a crack at it tomorrow.
http://en.allexperts.com/q/Motorcycle-Repair-837/1971-Honda-CB350-Twin.htm

Yep, that's exactly what i would suggest. I had the same problem over the weekend and it was nothing more than a timing issue. What sucks is that you have to dump the oil every time you need to crack the stator cover. The little light with the alegator clips was invalueable. I think I got mine for $3 at Lowes.

--Chris

 

[dcmspikes]

This is cheap at JCW. Would it work?
http://www.jcwhitney.com/autoparts/Product/tf-VehicleBrowse/s-10101/Pr-p_Product.CATENTRY_ID:2005149/p-2005149/N-111+1971+200730434+600001798/c-10111#BVQAWidgetID

Chrome-plated Ignition Coil, for 2-cylinder 12-volt Motorcycles that require a double ignition lead ZX013085X $32.99

you k now i was just looking at these over the weekend. for that price its worth having new ones for state of mind. i read some of the product reviews on the site. everyone was pleased with what they got. most said that they were a little large. if anyone has used or know someone that has used these on a vintage Honda application this could be a good product.

 

[dentedvw]

Well, the odd trouble continues. Yesterday I had a fellow come over to have a look, and he helped me ensure that the points are within spec, and that the timing is all lined up. I didn't have new points yet to put on there, or a new condenser, but the condenser appears pretty new, as does one points arm. The contacts on the pads look pretty good as well. To be sure, I cleaned them up with a fine emery cloth. You could see small sparks from each set of points, so it seemed to be working well.
But, it still only runs on one cylinder. It's still not always the same cylinder.

Could it still be the coils? I wish I had a known good set for reference.

The guy who came over suggested maybe I should check the valve clearances, but to wait until the engine is completely cooled off. Does this sound about right? Any other suggestions about what to check?

The plugs are newish, I bought them when I got the bike. The wires and plug ends appear to be in pretty good shape, though one is a bit short.

The carbs are recently rebuilt using Keyster kits, and they were in pretty good shape when I did it too, nothing really very gummed up. There is gas in both carbs, and there isn't really any air in the gas lines.

 

[DrJ]

I just went through a coil problem myself. This is what I did. I cut off about 1/4" from the ignition wire ends and took a look at the core. On 2 sets that I suspected were bad, the core was black and looked burned. On the third pair both cores showed a clean copper colour and guess what? Those were the ones that worked.

 

[dentedvw]

Yes, I checked that as well, one of the wires was a bit crudded up, so I shortened it to a shiny part, and reattached. Is there a better way to keep these ends on? They seem kind of flimsy. I paid $40 for one used coil without an end, so I had to use one that came on the bike. And then the cable was almost too short to use. Barely makes it.

 

[Fear My Twin]

First of all, Dont ever buy another part without asking here first, Im sure someone here would have sold you a coil for $20.

Secondly, I had spark on one cylinder too.

Went crazy trying to figure out what was wrong. Try swapping the condensers and see if you can get spark on the other cylinder.

Secondly, my problem turned out to be that the PO simply had the coil wired completely wrong. As simple as it sounds, run through your harness making sure all the bullet connectors to that cylinders coil are nice and clean AND all the connections are made between the same colors.

IE: Yellow wire [Connection] Yellow wire

NOT

Blue wire [Connection] Yellow wire like mine were hooked up.

I totally understand how frustrating it is. Trust me, the first time you take her for a ride and you learn to steer with the foot pegs you'll get more pleasure than your first time with a woman