Author Topic: cb350 four cylinders 1(most left) and 4(most right) not firing  (Read 10292 times)

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Offline Dos

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #25 on: October 08, 2014, 04:01:01 PM »
I'm having a hard time loosening the point gap screw.. I don't want to strip the thing.. When it does spark its orange compared to the left side that has white sparks. Maybe it could be the condenser? I'm going to fix the gap first. I have to set it to F and then I can loosen

Offline Dos

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #26 on: October 08, 2014, 05:33:58 PM »
Put in a new condenser and points from another bike..nothing

Offline Dos

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #27 on: October 09, 2014, 02:07:09 PM »
Sorry guys don't mean to annoy you and I may be a novice but I'm trying hard with the tools I got.. So far I have changed spark plugs, checked spark plug caps, swapped coil cords with opposite coil, changed right side points , swapped out both condensers and still nothing. I have drained the oil yet. Battery is running low .. Also, I'm getting backfires now

Offline flybox1

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #28 on: October 09, 2014, 02:36:06 PM »
was the yellow points wire in contact with the points plate?  did you verify in the dark that a spark is not jumping there?
D8EA plugs, yes?
What was your ohm reading on your caps?  did you cut the wire back some?
what about valve lash?  .002" IN and .003 EXH
what did you set your points gap at?
Carb clened and float height checked?

'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

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Offline Dos

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #29 on: October 09, 2014, 02:47:01 PM »
Yellow wire was not in contact
In the dark there is sometimes a spark but it's orangey
I'll have to borrow my friends multi meter again but i will get back soon

Offline Dos

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #30 on: October 09, 2014, 02:49:19 PM »
Also carb 1(most left) has always leaked gas from exit tubes. It stops when it's ridden.. Gas is coming out of it Noe when I try to start it not a lot though

Offline Davidov

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #31 on: October 10, 2014, 09:50:18 AM »
Check resistance across the coil.

Use this one. Don't worry about the number in this video. The procedure is what I'm getting you to see.
http://www.youtube.com/watch?v=xJMkt-MESHI
« Last Edit: October 14, 2014, 07:39:20 AM by Davidov »
-David

Offline flybox1

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #32 on: October 10, 2014, 10:05:27 AM »
Also carb 1(most left) has always leaked gas from exit tubes. It stops when it's ridden. Gas is coming out of it Noe when I try to start it not a lot though
the 350F float valves have a metal tip, and over time, they can wear their seal out against the float valve seat.  If they need replacing, they should be replaced as a set.
Debris in your gas can also lodge here, and hold the valve open, causing drips.  clean tank+working filter=clean carbs.  You'll also need to verify that your floats are set properly.  24mm is correct, not 21mm as noted in several places.
24mm holds the fuel at the correct level in the bowls (3-4mm below bolw gasket seam) often times this corrects any overflow. 
'78 750K (F3 engine) PD42b's, Modified airbox w/K&N  filter, 40/110 jets, 1 needle shim, IMS@ 1 turn out. Kerker + Cone 18" QuietCore

Past Bikes
1974 550K0 (stock), 1973 CB350F (stock), 1983 Yamaha XS400K (POS)
77/78 cool 2 member #3
"Knowledge without mileage equals bullsh!t" - Henry Rollins

"This is my CB. There are many like it, but this one is mine…"

Offline TwoTired

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #33 on: October 10, 2014, 10:09:44 AM »
Check resistance across the coil.
http://www.youtube.com/watch?v=rRQ45lT2d3c

If you use this procedure for testing SOHC4 coils, every single one will test bad, including a brand new one.
Lloyd... (SOHC4 #11 Original Mail List)
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Offline Dos

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #34 on: October 10, 2014, 01:35:07 PM »
I feel like it is definitely coil related. How can I properly check

Offline TwoTired

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #35 on: October 10, 2014, 01:45:33 PM »
Have you looked at the FAQ?

Primary should measure about 4.7 -ish ohms.
Secondary should measure about 15,000 ohms.  Neither primary nor secondary should connect to each other, so resistance = infinity is normal for SOHC4 coils.

The coils aren't magic.
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

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Offline Dos

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #36 on: October 10, 2014, 02:16:34 PM »
Yeah I have to just get a good multimeter. But good news I started her up and its sparking I took a picture while it was running. It is definitely the right point so I'm guessing that would go to the right coil

Offline xtravbx

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #37 on: October 10, 2014, 05:32:17 PM »
Where do you live?

Offline Davidov

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #38 on: October 11, 2014, 11:17:18 AM »
Check resistance across the coil.
http://www.youtube.com/watch?v=rRQ45lT2d3c

If you use this procedure for testing SOHC4 coils, every single one will test bad, including a brand new one.
Oops, forgot I found that during my 350 twin adventure. That would be misleading.

Have you looked at the FAQ?

Primary should measure about 4.7 -ish ohms.
Secondary should measure about 15,000 ohms.  Neither primary nor secondary should connect to each other, so resistance = infinity is normal for SOHC4 coils.

Dos, you really need to look these specs over first before you "feel" like it's coil related.

That picture shows sparking on the points plate? You need to see spark at the spark plug.
-David

Offline Dos

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #39 on: October 11, 2014, 08:35:35 PM »
Man this is just one thing after another lol. Battery died I gotta charge it now but I'll test all 4 spark plugs once its back up.

Offline Dos

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #40 on: October 11, 2014, 08:37:09 PM »
My cam chain tensioner bolt snapped off as well. So the screw is keeping the can chain at the right tension but it's stuck in there the head came off

Offline Davidov

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #41 on: October 12, 2014, 04:00:25 PM »
Your sentences are confusing.

So you have no spark out of the coil for 1 and 4?
-David

Offline Dos

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #42 on: October 12, 2014, 04:09:41 PM »
Sorry. No I have spark coming for 1 and 4 and not 2 and 3

Offline Dos

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #43 on: October 12, 2014, 04:19:54 PM »
This is driving me crazy. Coils 1 and 2 show a reading of 4.5 ohms from the two little output wires.

Offline TwoTired

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #44 on: October 12, 2014, 04:33:13 PM »
This is driving me crazy. Coils 1 and 2 show a reading of 4.5 ohms from the two little output wires.


One tiny step at a time, eh?
Step one of two show a good coil so far.
Lloyd... (SOHC4 #11 Original Mail List)
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Offline Dos

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #45 on: October 12, 2014, 05:22:21 PM »
I'm sorry. Okay so the coil on the left side is shoeing 4.5 ohms and that's when I stick the two prongs into the tiny connectors. The right coil is also the same. However the coil on the left side goes to cylinders 2 and 3 and the spark plugs don't fire when I test. The coil on the right that goes to cylinders 1 and 4 does.. Now I switched the connectors to the opposite sides and when I tried to electric start the bike shut off.. I can't turn it on there is no ignition light now.. I charged the Battery all day. I look at the rectifier which looks likes crap and one wire going into it looks like it melted and the wires are frizling apart.. I am at a loss idk what to do lol. I took the rectifier apart and I'm not to sure if I assembled it back together correctly

Offline TwoTired

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #46 on: October 12, 2014, 07:16:57 PM »
If you aren't going to read these posts, you probably aren't going to fix it with our help.

You have to measure the coil output resistance too, as I instructed earlier.  Then you can eliminate the coil as a problem source.  You can also (in addition) measure voltage across the points, both when they are open and when they are closed, and report the readings.

Less flail, more plodding, picking away at the unknowns, to build a store of knowns about the bike.
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

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Offline Dos

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #47 on: October 12, 2014, 07:33:49 PM »
Will do. How do I measure the resistance? I'm a little confused on how to test. There are 2 pins a female and male and I stick the negative and positive prongs on them and get the 5 ohms reading. I'm guessing that's the primary coil? How do I test the secondary?  There are two spark plug chords going out and two thickle metal prongs on either side I'll take a pic
« Last Edit: October 12, 2014, 07:35:59 PM by Dos »

Offline TwoTired

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #48 on: October 13, 2014, 01:30:32 AM »
Ever read the FAQ?

Or, do you insist we type out the procedure again here?
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline dave500

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Re: cb350 four cylinders 1(most left) and 4(most right) not firing
« Reply #49 on: October 13, 2014, 01:49:51 AM »
you can do it loyd!