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Discussion Starter · #1 ·
I worked my '73 CL350 a little harder than it liked today. Got it stuck in some ruts in central Oregon. After I finally got out I found that it wouldn't stay at idle. It ran ok, but not as good as it has been.
I pulled the carbs and re synced them. Figuring I might've bumped an idle screw in the struggle to break free of the ruts. I tuned it to a healthy 1200 rpms but found I was lacking power taking off from a start.
While it was idling I thought to pull the plug wires to see any change. Pulling the left wire off the plug made no difference. Pulling the right wire killed the engine. I swapped the plugs from either side to see if it was a plug issue, but the problem remained on the left side. I took a peek at the points and saw they were sparking on both sides.
The damnedest thing is the engine still responds when I pull the throttle on the left side only. So it's gotta still be firing somewhat.

I'm not sure what I should look into next. Any tips?

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Discussion Starter · #3 · (Edited)
Could this be a coil issue? I saw in another thread how to test a coil, and I'm no multi-meter wizard, but I set my fantastic harbor freight meter to the 20k ohm setting and connected to the female ends of the yellow wire that leads to the points, and the open green wire that's never had anything connected to it. My meter reads .01. If I did it right, I'm guessing that means I have a bad coil. But I'm cautious to confirm this.

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Discussion Starter · #4 ·
If you were revving the snot out of it I'd check you cam followers.
It looks like that involves taking off the head? I'm not exactly in an ideal area for a serious surgery like that.
I wasn't revving too high. No more than 5-6k. But it was hard work digging out of sandy gravel. I'm leaning towards a bad coil, but I'm not sure what else to consider.

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It looks like that involves taking off the head? I'm not exactly in an ideal area for a serious surgery like that.
I wasn't revving too high. No more than 5-6k. But it was hard work digging out of sandy gravel. I'm leaning towards a bad coil, but I'm not sure what else to consider.

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no, just take the tappet inspection caps off and check your clearance with a feeler guage. Although that's probably not it as it'd probably be really loud tapping sounds. But,... Easy to check.
 

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Discussion Starter · #6 ·
no, just take the tappet inspection caps off and check your clearance with a feeler guage. Although that's probably not it as it'd probably be really loud tapping sounds. But,... Easy to check.
Rad. Thanks! I'll check it in a bit, getting hot out here!

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So it it no spark, or it's just not firing the cylinder?
If you have spark then try and set your cam chain tension and double check your ignition timing. Check for actual spark first. Then plugs and plug caps/ignition wire condition.
 

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Discussion Starter · #8 · (Edited)
So it it no spark, or it's just not firing the cylinder?
If you have spark then try and set your cam chain tension and double check your ignition timing. Check for actual spark first. Then plugs and plug caps/ignition wire condition.
I suppose I'm not sure of the difference. At idle I can pull the boot off the left plug and not effect the idle at all.
While the boot is off there is no change in idle when I actuate the left carb throttle. But when it's on I can rev the engine when I actuate the left throttle.
How would I check the condition of the wires? They 'look' fine, but I'm not sure of any underlying problems.
Is checking the cam chain the same as checking the cam followers as previously mentioned?
Am I on a wild goose chase with a possibly faulty coil?

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Do you have a spare spark plug? If so, plug it into the non-firing boot and place it on the engine. Crank or kick the engine over and see if the plug sparks.

Cam follower is different than chain tension.
 

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you might go to a auto parts store and pick up a spark tester. About $6.00. Put it between the plug and the coil. If it lights up you have power to the plug . If not then you might have a coil or points problem. A very easy and fast check.


Bill
 

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When you took a peek at the points and noticed they were sparking, did you check to see when exactly they were sparking? I can't remember if you've done this from your previous posts, but it's up there to have a good running bike. Common motor has a good video on it. My two cents is check that the gap is close to spec but don't waste a lot of time on that. The closer they spark when they're supposed too the better your bike will run. I have a cover with a inspection hole so I can tweak them perfect with a clamp on strobe light while the bike is running.
 

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Since points can wear quickly and the gap change as a result, it's possible that the weak spark is caused by a really narrow points gap. It would run when the revs are elevated but might be too weak to run at idle. I'd go over all of it again just to be sure as doode suggested, including points and timing, and get the spark tester as Bill suggested too since it's cheap enough and you'll have it with you as you travel since this is your daily transportation now that you're out on the road

EDIT: what he said too^^^
 

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Discussion Starter · #13 ·
Thanks for the tips guys. I've exhausted my resources here in central Oregon, but I'll be in Reno next week. I'll get a spark plug tester there and troubleshoot what yall have suggested.
While it was running I moved the points back and forth and couldn't notice any change in the way it ran, but it wasn't a very precision experiment.
Luckily I'm staying in farm country for the Eclipse and our friends loaned me their little Honda ATV to get me around their property in the mean time so I'm in good company!

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Uh, you don't need a plug tester. Just pull the existing plug and lay it on the engine and see if it sparks.

When you did your experiment, moving the points around while running, was this before or after the running issues that led to you starting this thread? Why not just take the time to check your point gap and ignition timing?
 

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Discussion Starter · #15 ·
Uh, you don't need a plug tester. Just pull the existing plug and lay it on the engine and see if it sparks.

When you did your experiment, moving the points around while running, was this before or after the running issues that led to you starting this thread? Why not just take the time to check your point gap and ignition timing?
This was after. It was running great before I felt the desire to bring my problems here.
I'm hesitant to properly check the point gap because I'm staying at a friends house and don't want to drip oil on their driveway by taking off the crank cover dealy. I also don't have a tester light with me to check the timing.
It's looking like I don't have the ability to fix my bike where I am currently, and I just have to gather knowledge until I can get to a bigger city with more resources.
I'm traveling the country in an RV with a couple bikes on a trailer, so I'm not always in the best position to really tear deep into my bike.
But with all your help it looks like I've got a few more things to check out before spending $100 on new coils. Thanks everyone!

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Do you have feeler gauges, a multimeter and some cardboard? If so, that is all that is needed. The cardboard is to keep the oil off he driveway. The multimeter is what I use to set ignition timing. The feeler gauges are for points gap and valves too. If you don't want to dig into it then I won't press you.
 

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Discussion Starter · #17 ·
Do you have feeler gauges, a multimeter and some cardboard? If so, that is all that is needed. The cardboard is to keep the oil off he driveway. The multimeter is what I use to set ignition timing. The feeler gauges are for points gap and valves too. If you don't want to dig into it then I won't press you.
My stupid brain hadn't considered that my multimeter could serve the same purpose as a tester light! I've got a feeler guage set too.
I've never checked my timing before, and my only knowledge on the procedure is from watching the common motor video on it. Hopefully I'll have some time this evening to try it out. Thanks.

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First

Pull the plug on the non firing side.
How does it look?
Push it into the plug cap and lay it on the engine.
Remove the other plug cap.
Turn the bike on and hit the starter. Do you see spark from the plug?
 

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Discussion Starter · #19 ·
First

Pull the plug on the non firing side.
How does it look?
Push it into the plug cap and lay it on the engine.
Remove the other plug cap.
Turn the bike on and hit the starter. Do you see spark from the plug?
I finally made it to the big city!
I did as you suggested. Plugs are a bit dark, but nothing terrible. I am getting spark on both sides. So I guess somewhere some how the timing got messed up? I'll rewatch the common motor video and set my timing. Wish me luck!

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Discussion Starter · #20 ·
Well. I went ahead and bought new plugs for good measure. Set the timing, and my problem persists.
It idles okay, but is slow to rev on the throttle and when coming back down to idle. There's no difference in idle whether the left plug is connected or not.
But I set the timing, so I'm lost on what to do next.

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