Author Topic: plug caps  (Read 1356 times)

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Offline hymodyne

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plug caps
« on: July 01, 2005, 12:29:57 PM »
Hi all,

I've got problems with cylinders 3 and 4. I started the bike and those pipes are cold. when I put an spare plug into those caps, I get a visible but weak spark. with my ohm meter set on 20K, they read 8.6 (#4) and 10.4 (#3) ohms. These are replacement coils (used) from a '72 cb500.

the carbs have been rebuilt and completely overhauled, and at times, all four pipes have been hot--just not 3&4 right now.

suggestions?

hym
"All things are ready if our minds be so."

Offline TwoTired

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Re: plug caps
« Reply #1 on: July 01, 2005, 02:39:31 PM »
It would be interesting to know what the resitance of the 1&2 plug caps are.  And, if you swap them with 3&4 does the problem move with the plug caps?

Are your plugs clean?  Dry or wet?
Are you using resistor plugs?  What is their number?

What is the voltage across each set of open points?

Are you using the stock, points, etc?

Are there any cracks in the ignition lead wires?
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 bryanj

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Re: plug caps
« Reply #2 on: July 02, 2005, 03:20:31 AM »
Cant be the coils as 3 & 4 are off seperate coils
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!