more plug color questions...

GoldenMotor.com

steampunk

Member
Mar 10, 2011
440
0
16
lakewood co
i keep finding conflicting info on a 2 stroke plug colr reading ....it looks like it is a immenant failure indication at some places and not at thers...4 strokes at 3/4 throttle but runs great other then that....both plugs are out of 48's...im at 6k ft elevation .... one on the left is from a port matched motor with a expansion chamber and rt carb running a 70 size jet and 32:1 valvoline the other is an stock motor with a nt carb and ht pipe...(the chrome muffler)..24:1 valvoline for break in..both were pulled after a reg ride...not doing a plug chop...idled out etc...the tweaked motor has 400 on it the other is still less then a 100 still in breakin...plug on the right was new before a simple 20 miler with hills last night

im thinking too rich still? or am i trying to blow up my motor? ....im probably just too paranoid but i cant seem to find a solid answer...all the conflicting stuff i have found has left me kinda doubting my judgement



 
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Norman

LORD VADER Moderator
Jan 16, 2008
2,605
6
38
71
pampa texas
At the altitude your at I'm thinking a 0.65mm main would be the way to go.
The left plug looks kind of rich, the left plug looks lean but it does have a dark color same as the left plug plus you said it was a new plug. Different types of 2 stroke oils and gas will make the spark plug different colors. But basically black oily is too rich and a white insulator is too lean the center electrode will also have a blue tint if it getting real lean. Shoot for a tan color on the center insulator part of the plug. Some may be a darker or a lighter tan again depending to the fuel and what additives are in the fuel and the type of oil used.
Could be the right plug needs a little more fuel in the lower setting so a clip change of 1 notch to make it a little richer.
You really need to do a wot run chop the ignition and then read the plug to get the main jet set properly. Then do the lower or needle settings.
running a 32 to 1 oil mix is in my opinion better than a 25 to 1 mix. I prefer using Polan syn 2 stroke oil at 40 to 1 with regular gas. This fuel mix works fine in my bikes and in my holmlite weed eater.
When your breaking in an engine it won't hurt to run 25 to 1, I usually only do 1 to 2 tanks of that fuel mix and they are only filled half full, then switch over to the 40 to 1 then tune the engine.
I also run a spark plug gap of 0.017 to 0.020". Looks like your running more of that for your gap.
 
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steampunk

Member
Mar 10, 2011
440
0
16
lakewood co
the motor that the plug on the right is in...just tipped over 100 miles so its getting put on 32:1...then i may get a solid reading off it...the grey plug (left) is in my modded motor...it got up to 250 today after a hard pull but it hasnt exibited any signs of over heating...ill be putting a .068 in that one...its currently running a .070..... and probaly a .065/.067 in the other motor...it has a stock carb and pipe on it....thank you for the input norman
 
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