How’s this plug look
#1
06-08-2018, 08:29 PM
How’s this plug look
Recently did my engine over, 85” Revolution Performance 10.5:1 pistons, head work and new valve train, got about 1000 miles and a change of weather since dialing in the carb. Seemed a little fat so I bought new plugs and readjusted, this is what they look like, I think they’re good, the first go around they were a little too white, so I went about a quarter turn with the mixture screw. A little feed back would be appreciated.
Last edited by Ironworker69; 06-08-2018 at 08:33 PM.
#2
06-08-2018, 08:50 PM
Seasoned HDF Member
How many miles on that plug.? It's hard to get a good reading without putting roughly aa100 miles on them... Today's fuels don't leave deposits like the past... They Look to have a bit of soot on the ring. Might be a little too rich. One way you can test for a proper mixture at idle is with a bottle of propane with a regulator and surgical tube. Remove the air cleaner, start the bike and run till warm. Point the surgical tube into the throat of the carb. Slowly crack the valve, if the idle goes up your idle mixture is lean. If it goes down your rich...
Last edited by 98hotrodfatboy; 06-08-2018 at 08:52 PM.
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ubreal (09-29-2018)
#3
06-08-2018, 09:18 PM
Seasoned HDF Member
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Evo-Wes (09-23-2023)
#4
06-08-2018, 10:36 PM
How, specifically did you do your plug chop?
Back in the day when I was trying to tune a Yamaha RD350 (way before wideband tuners existed, not to mention this is a 2-stroke) plug chops were the only way to get an idea where your AFR was. The MO for plug chops was as follows:
Hold your speed for a while, like 30 seconds
Then do all these at the same time: slam throttle closed, hit kill switch, pull in clutch and coast to a stop
Pull plug, see color
But as been said, good luck with today's cleaner fuels. My speculation on that specific plug is you just pushed the choke back in and built some speed for a mile or so, then pulled over to pull the plug.
Back in the day when I was trying to tune a Yamaha RD350 (way before wideband tuners existed, not to mention this is a 2-stroke) plug chops were the only way to get an idea where your AFR was. The MO for plug chops was as follows:
Hold your speed for a while, like 30 seconds
Then do all these at the same time: slam throttle closed, hit kill switch, pull in clutch and coast to a stop
Pull plug, see color
But as been said, good luck with today's cleaner fuels. My speculation on that specific plug is you just pushed the choke back in and built some speed for a mile or so, then pulled over to pull the plug.
Last edited by Mattbastard; 06-08-2018 at 10:37 PM.
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bentparts (06-09-2018)
#5
06-09-2018, 04:15 AM
How, specifically did you do your plug chop?
Back in the day when I was trying to tune a Yamaha RD350 (way before wideband tuners existed, not to mention this is a 2-stroke) plug chops were the only way to get an idea where your AFR was. The MO for plug chops was as follows:
Hold your speed for a while, like 30 seconds
Then do all these at the same time: slam throttle closed, hit kill switch, pull in clutch and coast to a stop
Pull plug, see color
But as been said, good luck with today's cleaner fuels. My speculation on that specific plug is you just pushed the choke back in and built some speed for a mile or so, then pulled over to pull the plug.
Back in the day when I was trying to tune a Yamaha RD350 (way before wideband tuners existed, not to mention this is a 2-stroke) plug chops were the only way to get an idea where your AFR was. The MO for plug chops was as follows:
Hold your speed for a while, like 30 seconds
Then do all these at the same time: slam throttle closed, hit kill switch, pull in clutch and coast to a stop
Pull plug, see color
But as been said, good luck with today's cleaner fuels. My speculation on that specific plug is you just pushed the choke back in and built some speed for a mile or so, then pulled over to pull the plug.
#6
06-09-2018, 05:30 AM
Looks rich on the low end (like mentioned the base ring), timing looks ok with the line at the bend, maybe a tad advanced.
The spot on the base ring should be thin, almost “see through”. However, if you used the enrichener, then reading is not accurate.
Need a side view to tell more. And I agree more miles tell a better story. YD
The spot on the base ring should be thin, almost “see through”. However, if you used the enrichener, then reading is not accurate.
Need a side view to tell more. And I agree more miles tell a better story. YD
Last edited by Yankee Dog; 06-09-2018 at 05:32 AM.
#7
06-09-2018, 05:58 AM
Seasoned HDF Member
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#8
06-09-2018, 06:57 AM
Looks rich on the low end (like mentioned the base ring), timing looks ok with the line at the bend, maybe a tad advanced.
The spot on the base ring should be thin, almost “see through”. However, if you used the enrichener, then reading is not accurate.
Need a side view to tell more. And I agree more miles tell a better story. YD
The spot on the base ring should be thin, almost “see through”. However, if you used the enrichener, then reading is not accurate.
Need a side view to tell more. And I agree more miles tell a better story. YD
#9
06-09-2018, 08:16 AM
Seasoned HDF Member
#10
06-09-2018, 09:59 AM
