Author Topic: Spark plugs??  (Read 10128 times)

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Jim Shea

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Re: Spark plugs??
« Reply #25 on: September 28, 2005, 08:03:45 AM »
Geff,
How did you get on with changing the air filter? did you have any problems?

Offline TwoTired

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Re: Spark plugs??
« Reply #26 on: September 28, 2005, 12:49:52 PM »
D7ES is the old NGK number for the correct spark plugs for all the CB550s. 
D7EA is the new number to replace the old NGK number.  My understanding is that NGK just changed their numbering system since the time the bike was manufactured and manuals were printed.

Any plug with R in number is a resistor plug (DR7ES).  And, is NOT correct for a CB550 unless the plug caps have also been changed to NON resistor.

Running multiple resistors in the ignition, shortens the effective life of the spark plugs, by marginally reducing the peak voltage to the spark gap.  This can reduce performance.  As the plug approach end of life, they need more voltage to fire. The stock CB550 ignition system has a lower upper limit to the voltage it can develop, unlike today's modern High Energy systems that employ resistor type plugs.
Lloyd... (SOHC4 #11 Original Mail List)
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Offline GeoffT

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Re: Spark plugs??
« Reply #27 on: September 28, 2005, 01:19:01 PM »
D7ES is the old NGK number for the correct spark plugs for all the CB550s. 
D7EA is the new number to replace the old NGK number.  My understanding is that NGK just changed their numbering system since the time the bike was manufactured and manuals were printed.


Hi Two Tired, it could well have been D7EA. I just took the plugs out to have a quick look and compare with the pics in the haynes manual. I noticed the were 7 a somthing. The guy i bought the bike from put new plugs in last year.

How long should they last by the way?

Offline GeoffT

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Re: Spark plugs??
« Reply #28 on: September 28, 2005, 01:23:39 PM »
Geff,
How did you get on with changing the air filter? did you have any problems?

Put a new air filter in a few months ago on discovering there was nothing in the air filter box. Dave silver was able to provide all the gubbins for inside the box except the locking spring thingy. Fits in snug any way.

Going to change the oil filter soon. Its been on a year. I think i read you should change it every year. Never done it before but I have read on this site that we need to be carefull not to overtighten the nut or bolt on the oil filter housing. ;)

Offline TwoTired

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Re: Spark plugs??
« Reply #29 on: September 28, 2005, 01:50:43 PM »
The owner manual says the clean and regap the plug at 6000 miles, replace them at 12000 miles.

The spring thingy in the air filter is rather important.  It presses the filter forward to seal against air bypassing the element.  The filter loose in the box won't effectively seal and control the airflow.
Don't confuse the insertion resistance of the oil breather stand pipe as an effective seal for the filter outlet to the carbs.
Might be able to make a wooden wedge to take the place of the spring.

Or, I could post a pic of one so you could make something for the function.
Cheers,
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 GeoffT

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Re: Spark plugs??
« Reply #30 on: September 28, 2005, 02:08:01 PM »
Two Tired

that is a great idea. If its not to much trouble. It is quite a tight fit as it is but any improvement would help.

Offline TwoTired

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Re: Spark plugs??
« Reply #31 on: September 28, 2005, 02:27:42 PM »
Here is is:
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 GeoffT

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Re: Spark plugs??
« Reply #32 on: September 29, 2005, 05:31:36 AM »
Interesting shape. Where and what does he clip on to?

Offline SteveD CB500F

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Re: Spark plugs??
« Reply #33 on: September 29, 2005, 05:36:36 AM »
It holds the air filter in (see earlier post on this thread).
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Offline bryanj

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Re: Spark plugs??
« Reply #34 on: September 29, 2005, 07:59:31 AM »
Got several of those spring thingies new if you want one email me direct (with an address) and i will work out shipping
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Offline TwoTired

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Re: Spark plugs??
« Reply #35 on: September 29, 2005, 10:06:52 AM »
Interesting shape. Where and what does he clip on to?

If you look toward the rear of the air box (inside).  You'll see a molded channel (surprise) the width of the spring.  The arch side goes against the filter.

Cheers,
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 GeoffT

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Re: Spark plugs??
« Reply #36 on: September 29, 2005, 10:29:50 AM »
Cheers guys great help once again. ;)

popeye

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Re: Spark plugs??
« Reply #37 on: September 29, 2005, 08:24:25 PM »
a dab of anti-seize on plug threads makes 'em easy to unscrew ;)

Jim Shea

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Re: Spark plugs??
« Reply #38 on: September 30, 2005, 12:49:54 AM »
One thing I did notice was that there was an amount of dirt, bits etc accumulated around the plug housing, before you remove the plug it is a good idea to blow any crap out of the plug area to stop it falling in to the barrel.