Author Topic: 73 CB350F, failed emissions; CO2 only  (Read 5590 times)

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Offline HondaMan

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Re: 73 CB350F, failed emissions; CO2 only
« Reply #25 on: June 22, 2012, 08:42:13 PM »
Oil is new, plugs are not.  I was under the impression that this was not an ignition issue but an air ratio problem and that plugs would help (unless they showed signs of excessive carbon etc.

In that case I should consider changing the points too.

You might actually find that filing and cleaning, then resetting gap and timing, works better than all but the genuine Honda TEC points sets. It's an interesting thing I've been studying these last 2 years: the tungsten on most points besides the TEC brand is pretty cheap (maybe impure, like Chinese lead in their batteries) and doesn't make a good spark. Reason: it lets the arc (upon opening) continue too long, which dissipates part of the spark energy by collapsing the coil's magnetic field too quickly - much like the Dyna S triggers.

The "cheap" tungsten (or whatever other feature is causing this phenomenon) is not extinguishing the arc-flame, in tech terms...I just got some TEC points from the Honda shop and tried them, and by golly, they work as I am used to seeing from a long time ago!
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Offline Trevdawg

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Re: 73 CB350F, failed emissions; CO2 only
« Reply #26 on: June 22, 2012, 09:06:38 PM »
I think the sea foam might have been against you here. Typically in a car when you run that stuff it shoots tons of black out to "clean" the engine. That probably caused some of the issue.

Offline scottly

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Re: 73 CB350F, failed emissions; CO2 only
« Reply #27 on: June 22, 2012, 09:13:44 PM »
Oil is new, plugs are not.  I was under the impression that this was not an ignition issue but an air ratio problem and that plugs would help (unless they showed signs of excessive carbon etc.

What do the plugs look like? Please post pictures.
Don't fix it if it ain't broke!
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Offline rboe

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Re: 73 CB350F, failed emissions; CO2 only
« Reply #28 on: June 22, 2012, 09:53:44 PM »
Scott, I pulled the far right plug, nice and light tan. Looked good.

Hondaman; I was wondering about the points. they are old, have no idea how much time they have on them but they could very well be the weak link here. If I order Honda branded parts I should be getting the TEC brand points? I just received two new points files. Just may give them a whirl.

I have not messed with points since my old CJ360T days; holy moly that was a while back (and I'm not saying I was much good at it then either; maybe this is my chance to forget old bad habits!!!!).

I wonder how much gas I should burn through her to settle down the effects of the sea foam? Thinking out loud there. In any event, I tried to get her going on the cheap and easy  - which actually worked! - but getting her legal is going to take a bit more. Will look into the collectors insurance loop hole. Getting her plated and riden will do more good at this point. Will give me some wiggle room really look into the combustion bits. She seems to run stronger each time I sneak out for a test ride.
1974 CB350F
2008 XR650L
2012 Griso SE

Past iron
1971 Suzuki TS125
1977 Honda CJ360T
1981 Kawasaki 550Ltd
2000 Moto Guzzi Quota

Offline rboe

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Re: 73 CB350F, failed emissions; CO2 only
« Reply #29 on: June 22, 2012, 09:55:39 PM »
The last couple issues of Cafe' Racer they talk about converting a bike to pointless ignition. I'm wondering if that is a route to consider. Anyone here do that for their small Honda?
1974 CB350F
2008 XR650L
2012 Griso SE

Past iron
1971 Suzuki TS125
1977 Honda CJ360T
1981 Kawasaki 550Ltd
2000 Moto Guzzi Quota

Offline scottly

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Re: 73 CB350F, failed emissions; CO2 only
« Reply #30 on: June 22, 2012, 10:01:27 PM »
Have you checked ignition timing?
Don't fix it if it ain't broke!
Helmets save brains. Always wear one and ride like everyone is trying to kill you....

Offline rboe

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Re: 73 CB350F, failed emissions; CO2 only
« Reply #31 on: June 22, 2012, 10:08:23 PM »
No sir I have not. I have some errands to do tomorrow so tomorrow evening or Sunday AM (no garage, in the afternoon it is well over 100 degrees in the shade and I tend to melt so little work gets done outside and naps become very high priority  :D  ).

I did drag out the dwell meter and the strobe. Tried to make sense of the directions and didn't have the time to reinvent the wheel before heading to the vet and put it off. It's on the docket to do now.
1974 CB350F
2008 XR650L
2012 Griso SE

Past iron
1971 Suzuki TS125
1977 Honda CJ360T
1981 Kawasaki 550Ltd
2000 Moto Guzzi Quota

Offline scottly

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Re: 73 CB350F, failed emissions; CO2 only
« Reply #32 on: June 22, 2012, 10:16:04 PM »
Yeah, it's f'n hot, even up here. Conserve your energy and do a quick check with the strobe for now; worry about dwell later.
Don't fix it if it ain't broke!
Helmets save brains. Always wear one and ride like everyone is trying to kill you....

Offline tomkimberly

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Re: 73 CB350F, failed emissions; CO2 only
« Reply #33 on: June 22, 2012, 11:52:34 PM »
The last couple issues of Cafe' Racer they talk about converting a bike to pointless ignition. I'm wondering if that is a route to consider. Anyone here do that for their small Honda?

Dyna S, I have it on my 350F, set it and forget it.

Tom

Offline rboe

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Re: 73 CB350F, failed emissions; CO2 only
« Reply #34 on: June 23, 2012, 11:47:49 AM »
Sold! Have one coming in. My past experience with points; the bike and I are better off avoiding them. I have an extra plate with points so at any time it can be made stock if need be.

Took the Griso out for breakfast this morning. What a transition going between the two.  ;D
1974 CB350F
2008 XR650L
2012 Griso SE

Past iron
1971 Suzuki TS125
1977 Honda CJ360T
1981 Kawasaki 550Ltd
2000 Moto Guzzi Quota

Offline rboe

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Re: 73 CB350F, failed emissions; CO2 only
« Reply #35 on: June 23, 2012, 06:44:32 PM »
Checked the timing this evening. Dead on. Removed plugs 1 & 4, posting pics here. Ran it a bit, checked the header temps and they are way off now (messed with the air screws as advised earlier) so when my four cylinder adaptor comes in I need to sync them.

This is the number one plug.
1974 CB350F
2008 XR650L
2012 Griso SE

Past iron
1971 Suzuki TS125
1977 Honda CJ360T
1981 Kawasaki 550Ltd
2000 Moto Guzzi Quota

Offline rboe

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Re: 73 CB350F, failed emissions; CO2 only
« Reply #36 on: June 23, 2012, 06:45:03 PM »
The number four plug.
1974 CB350F
2008 XR650L
2012 Griso SE

Past iron
1971 Suzuki TS125
1977 Honda CJ360T
1981 Kawasaki 550Ltd
2000 Moto Guzzi Quota