Author Topic: Spark Plug Color  (Read 1681 times)

Offline peter

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Spark Plug Color
« on: 27.03. 2011 16:20 »
In my BSA Gold Flash Jg.1954 the left spark plug is always brown, and the right spark plug is always sooty and black. The bike runs quite well. Do I have to change something anyway.
Peter
1956 Royal Enfield Bullet 350
1956 AJS 18s
1949 Royal Enfield 500 J2
1954 Golden Flash 650
1985 Virago V1000
2001 Wildstar V1600
1966 Velosolex 50
1999 Virago XV 1100
2012 Kawasaki W800
2016 KTM Duke 390

Offline lawnmowerman

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Re: Spark Plug Color
« Reply #1 on: 27.03. 2011 17:39 »
Hi Peter

A carb bias spacer may help - angle it towards the brown plug and it may even things up. I think they are available from Draganfly - or possibly Cake St classics. Maybe an idea to fit new plugs after so you can see the colour change.

Jim
1959 A10 SR
1938 Wolseley 14/60
1955 Ferguson TEF20 tractor
1965 Ferguson 135 tractor
1952 Matchless G80 rigid
1960 BMW R60
1954 Matchless G80S
1955 Ariel 500 VH
1951 Sunbeam S7DL
1960 Matchless G12 with Watsonian Monza
......and loads of lawnmowers

Too old to Rock and Roll but too young to die  (Jethro Tull 1976)

Online muskrat

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Re: Spark Plug Color
« Reply #2 on: 27.03. 2011 19:46 »
G'day Peter,
                brown is good, black is either oil or fuel. Get a mate to follow you on a ride and report any smoke from the right pipe. Blue is oil, black is fuel. Black, try Jim's fix. Blue is rings or valve guide. Check compression then add 1cc of oil down plug hole and test again. If comp goes up rings are sus. Another quick fix is to use a hotter plug in the right pot, B7ES in left and B6ES in right.
Test and report back.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, .
Australia
Muskys Plunger A7

Online BSA_54A10

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Re: Spark Plug Color
« Reply #3 on: 28.03. 2011 12:59 »
Also check carefully the timing.
Some of the cam rings are not exactly 180 deg and a slightly out of time spark can also give you sooty plugs
Bike Beesa
Trevor

Offline beezalex

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Re: Spark Plug Color
« Reply #4 on: 29.03. 2011 19:09 »
Judging mixture by the color of the top of the plug went out the window with modern fuels and the removal of tetraethyl lead.  That said, if your plug has dry soot at the top of the insulator, it's way too rich, if it's greasy soot you're burning oil. You should have neither.

If you really want to figure out your mixture by reading plugs, you need to look at the base of the insulator.   You can either do this by exposing the entire insulator by cutting the threaded portion of the plug off or getting a plug reader (really and otoscope).  The following links will help you interpret what you see:
http://www.strappe.com/plugs.html
http://www.mindsciencemotorsports.com/graphics/PLUG%20TECH.htm
http://hondaspree.net/wiki/index.php5?title=Carb_-_Lean/Rich_Tutorial
Alex

Too many BSA's


Offline peter

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Re: Spark Plug Color
« Reply #5 on: 29.03. 2011 21:55 »
Thank you for your advice, I will try out some advice.
If the problem is solved, I will answer
Thank you all, Peter
1956 Royal Enfield Bullet 350
1956 AJS 18s
1949 Royal Enfield 500 J2
1954 Golden Flash 650
1985 Virago V1000
2001 Wildstar V1600
1966 Velosolex 50
1999 Virago XV 1100
2012 Kawasaki W800
2016 KTM Duke 390

Offline renos-a10

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Re: Spark Plug Color
« Reply #6 on: 30.03. 2011 08:10 »
Good morning Peter,

I have the same problem and i check timing first.The problem is solved.
So check your timing.
Good luck
Renos
1954 BSA A10 Plunger
Cyprus

Offline peter

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Re: Spark Plug Color
« Reply #7 on: 08.04. 2011 19:30 »
1.Compression is well
2. a mate followed me he havent seen  smoke from the right pipe.
a new Problem, if I drive very slowly so I have  misfire in the pipe,  I think I have to ckeck the timing.
Peter
1956 Royal Enfield Bullet 350
1956 AJS 18s
1949 Royal Enfield 500 J2
1954 Golden Flash 650
1985 Virago V1000
2001 Wildstar V1600
1966 Velosolex 50
1999 Virago XV 1100
2012 Kawasaki W800
2016 KTM Duke 390