Author Topic: 350F plug chops.. I finally got a chance to do it.  (Read 850 times)

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Offline fmctm1sw

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350F plug chops.. I finally got a chance to do it.
« on: July 19, 2009, 04:32:20 PM »
Well, here it is.  My bike (seemingly) runs real good.  I looked at my plugs during a 1000 mile service and they were black :(   So here they are:  1/4 throttle first and then 3/4 to full (I was more watching the road than the marks on my throttle on that one).  The 1/4 chop I rode over 3 miles, had a lot of wide open space.  The 3/4 full not near as far, only enough to run it up to 80 or so.  Thoughts?


*edit* and I don't know if you can see it but there's a deposite of some sort on the electrode on 2, 3, and 4 of the 3/4 to full plugs..

Trying to add bigger pictures...
« Last Edit: July 19, 2009, 04:53:07 PM by fmctm1sw »
Quote from: 754
Dude is that a tire ? or an O-ring..??

Quote from: inkscars
This is not a pod thread
This is not a #$%* on my vacuum gauges thread
This is a help or GTFO thread.

1973 CB350F
1973 CB350G
1975 CB550K
1983 GL650I
1973 CB750K3 (http://forums.sohc4.net/index.php?topic=92888.0)
1984 Kawasaki KLT-250 (AKA 3 wheeler of death)
1994 Honda TRX300
1999 Honda TRX250

Offline Flying J

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Re: 350F plug chops.. I finally got a chance to do it.
« Reply #1 on: July 19, 2009, 04:38:22 PM »
I need to do a plug chop too. What plugs did you use? Cheap ones or standard.

Offline fmctm1sw

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Re: 350F plug chops.. I finally got a chance to do it.
« Reply #2 on: July 19, 2009, 04:39:31 PM »
Ah good point.  These are NGK D7EA which is one range hotter than standard.
Quote from: 754
Dude is that a tire ? or an O-ring..??

Quote from: inkscars
This is not a pod thread
This is not a #$%* on my vacuum gauges thread
This is a help or GTFO thread.

1973 CB350F
1973 CB350G
1975 CB550K
1983 GL650I
1973 CB750K3 (http://forums.sohc4.net/index.php?topic=92888.0)
1984 Kawasaki KLT-250 (AKA 3 wheeler of death)
1994 Honda TRX300
1999 Honda TRX250

Offline TwoTired

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Re: 350F plug chops.. I finally got a chance to do it.
« Reply #3 on: July 19, 2009, 11:45:24 PM »
First thing to cure/solve is why they aren't all showing the same deposits.

Valve adjust.
Compression numbers.
Ignition timing/ ignition lead inspection.
Carb boot sealing
Carbs clean with in-spec parts, adjusted equally. (and synchronized)
Air inlet differences/ choke butterflies proper.

Any exhaust obstructions?
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 flybox1

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Re: 350F plug chops.. I finally got a chance to do it.
« Reply #4 on: July 20, 2009, 07:30:52 AM »
First thing to cure/solve is why they aren't all showing the same deposits.

Valve adjust.
Compression numbers.
Ignition timing/ ignition lead inspection.
Carb boot sealing
Carbs clean with in-spec parts, adjusted equally. (and synchronized)
Air inlet differences/ choke butterflies proper.

Any exhaust obstructions?

+1 on all of the above.

#2-3-4 look ok(tan) on your 3/4-full, but might show different if you were able to run it longer to get a more accurate result. #1 looks a little lean.
'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

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