[FUnk]

Hey guys, I just recently did a full tune up on my 99, including completely disassembling and cleaning the carb. After re assembly I set the a/f screw to what I believe was 2 3/4 turns out from lightly seated. I've now put about 45 miles on the bike since and I figured I'd pull the plugs and take and look. my question is how exactly do I tell if I'm rich or lean or just right according to my plugs , I'll attach a few photos of my plugs as well, thank you!

 

[flitecontrol]

Here's a chart. Spark Plugs

 

[7milesout]

Funk - How did the bike ride? Was it responsive? Have any running problems?

According to guys who do this, the way to read a plug is to hold the throttle wide open for as long as you can (I guess), then kill the engine, coast to a stop and then pull a spark plug.

I accomplished it a more modern way. See this thread: https://www.hondarebelforum.com/f18/52mm-afr-gauge-mounting-122021.html

If it rode responsively, your tune is likely good. It's a dynamic affair. Sometimes it's rich, sometimes it's lean, depends on conditions.

 

[DNMenzies1]

2 3/4 turns seems a bit rich I would think 1 1/4 - 1 1/2 would be a better range. These engines don't seem to be that fussy, mine ran with nearly half choke for 10 years and I didn't know it, I bought it off the show room that way. I would start with 1 1/2 turns and check the performance and the mileage, burn a tank full then check the plug, it should be a light brown. If you are getting about 60 MPG and it will do 65 - 70 MPH, you are there. If you can operate in that range I would not touch it.

 

[flitecontrol]

2 3/4 turns is what Honda recommends for the initial setting on second generation Rebels.