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Discussion Starter · #1 · (Edited)
I previously posted about my wiring hell that I completely resolved with yalls help. Now, my problem is I can't get the engine to start. I've got spark on both plugs. The previous owner was riding it just on the right cylinder. I replaced the left ignition coil and now I have spark on both sides and they are even. Except the new problem is when I set the points, I'll get spark but no combustion.

The carburetors have been completely disassembled, cleaned, and brass parts replaced.

The engine fired after the carburetors were cleaned - just right cylinder worked. This was before new ignition coil.

I bought brand new points and set them according to the CMC youtube video. I want to make sure I didn't do anything wrong so I want to explain what I did and see if you guys agree what I did was right:

I made sure left cylinder was on compression stroke, and right when it was at LF, I made the test light go from off to on. Then I rotated 180 degrees ccw and did the same with the right points until light turned on at F.

When try starting it, though, I get heat and loud backfires coming out of the left cylinder, but absolutely nothing from the right. Right side is cold. Smoke comes from left. I switched the spark plugs to other sides and had no success. These are spark plugs from previous owner. The bike is wired to my Suburban's battery while it's running so I don't run out of amperage. I feel like the problem has to be about how I'm adjusting the points.

Compression seemed equal when running it before I tried fixing things.

Why does everything I touch get destroyed.

Any suggestions or ideas? I'm almost to the point of towing this to a shop.
 

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Couple thoughts:

I can't remember why, but something is telling me to not use a car battery. I'd be very cautious with that. Also, you probably aren't destroy everything you touch, it just so happens that we're all the kind of masochists who like to beat our heads against the wall working on 40 year old machines that need to be finely tuned.

Anyway. Point 1 - check your (motorcycle) battery. If it's fully charged and a multimeter shows less than 12.6v, time for a new one. These bikes run like crap with a bad battery (and I have no idea how hooking up a big ole Suburban battery would treat it).

Point 2 - are you doing this with the points cover on or off? If it's on, take it off. The points can short through the points cover and you're in no danger with it off in your garage (put it back on before you ride, with electrical tape on the inside if that turns out to be the problem).

Point 3 - get new spark plugs. RockAuto has them for like $1.50 per, get just a crapload of them and swap them out whenever they get too crappy while you're tuning.
 

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Discussion Starter · #4 ·
When your points open is when the spark happens so that's when you should be on F or LF

Light off, not on
Oh wait so was I completely backwards? I want it to be from when the light is on to when it turns off right at the F or LF? now I'm embarrassed. I'll be back on this in the morning.


Couple thoughts:

I can't remember why, but something is telling me to not use a car battery. I'd be very cautious with that. Also, you probably aren't destroy everything you touch, it just so happens that we're all the kind of masochists who like to beat our heads against the wall working on 40 year old machines that need to be finely tuned.

Anyway. Point 1 - check your (motorcycle) battery. If it's fully charged and a multimeter shows less than 12.6v, time for a new one. These bikes run like crap with a bad battery (and I have no idea how hooking up a big ole Suburban battery would treat it).

Point 2 - are you doing this with the points cover on or off? If it's on, take it off. The points can short through the points cover and you're in no danger with it off in your garage (put it back on before you ride, with electrical tape on the inside if that turns out to be the problem).

Point 3 - get new spark plugs. RockAuto has them for like $1.50 per, get just a crapload of them and swap them out whenever they get too crappy while you're tuning.
I've been getting a nice spark from both but will try if the above comment does not help. The suburban has a 12V battery, just a lot more CCA, which I do not believe will matter. I was getting sick of recharging my battery. Current battery is brand new AGM charged at 12.7. And yes, points cover has been off the whole time.
 

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Discussion Starter · #5 · (Edited)
This is the part of the video that confused me: https://youtu.be/nDvghJiJGFc?t=15m3s

Why does he want the light to kick on when at the LF? Isn't it supposed to fire when light is off and is no longer grounded?

Edit: I'm sorry I'm very new and trying to learn a lot about this. I really appreciate when you guys explain the logic behind this stuff.
 

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At 13:45 he explains the light goes on when the points open. I didn't finish watching but I'm assuming once the points close then it grounds and the light goes off?
 

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The spark appears when the points open.

This is the part of the video that confused me: https://youtu.be/nDvghJiJGFc?t=15m3s

Why does he want the light to kick on when at the LF? Isn't it supposed to fire when light is off and is no longer grounded?

Edit: I'm sorry I'm very new and trying to learn a lot about this. I really appreciate when you guys explain the logic behind this stuff.
 

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Discussion Starter · #8 ·
So that means I did adjust the points correctly.... What should I look for now? I can take a video tomorrow if needed.
 

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Toss the spark plugs and install some new ones.
 

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my guess is the advance unit too and doode's thought of ensuring right is right and left is left in hookup.

If the advancer got removed from the engine, then disassembled to clean/oil/inspect, etc. I think it can go together 180deg out (the lobe and spindle plate are timed together and that in reference to the camshaft installation pin). look for marks on the points cam base and match it to the spindle plate base (you know, the plate where the advance weights attach).

I always set my points at .014" at their highest point on the cam, or lobe, both sides then time from there.

are you chasing a carburetor problem through the points?

in any case, this is a puzzler!
 

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I'm on board with the possible carb issue or the cam being 180 out.

Just to clarify; the CAM can go back in 180 degrees out, the advancer cannot. The end of the cam has one little guide stud that slots into one slot on the advancer, they have a fixed relationship that's always in the same place. However, if you put your cam back in with the lobes facing the wrong direction (http://www.hondatwins.net/forums/48...129-installing-cam-back-my-cb360-180-out.html), your cam will be 180 out and by proxy, your advancer will just happen to be 180 degrees out, but it only goes in one way.
 

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Discussion Starter · #17 ·
I never removed the advance or cam when disassembling. Haven't touched it since had the bike when running. Bike has not run for about 3 months though. It did run just out of the right cylinder after cleaning carbs. Trying to get left cylinder and starter to run required a lot of small orders that it took a while to have the engine running. Is that long enough for a freshly cleaned carb to gunk up again? I was running ethanol-free gas. Is there any simple way of testing without disassembling it? I'm about to head to advance auto to pick up new spark plugs. And I am positive the points are connected to the correct leads. There was not enough slack to screw it up. Black to right point.

Thanks for the suggestions guys. I'll get back to you.
 

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Hmm. I'll be interested to see if the new plugs help. Unless you left them full of gas, I wouldn't think there'd be enough to really gum them up - I'd be more interested in your float heights and making sure they're adjusted correctly/really, really clean to start. There's always the "spray some starter fluid into the intake while trying to start it and see if it vrooms" verification method to check that.
 

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Discussion Starter · #19 ·
Hmm. I'll be interested to see if the new plugs help. Unless you left them full of gas, I wouldn't think there'd be enough to really gum them up - I'd be more interested in your float heights and making sure they're adjusted correctly/really, really clean to start. There's always the "spray some starter fluid into the intake while trying to start it and see if it vrooms" verification method to check that.
Got the new plugs I'll try them tomorrow. I adjusted my float heights according to the CMC youtube video. They were initially wildly different and nowhere near spec. After adjustment the right cylinder worked fine.
 

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Discussion Starter · #20 · (Edited)
New plugs in. Is this a big enough spark? They seem smaller than the previous for whatever reason. Manual said I should have a fat blue spark.

 
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