New plugs. Help with reading. Rich-Lean?

After 12 long months, my 3rd gen is fully rebuilt. Still dialing in fuel mixture & carbs. Bike has been rich forever. On the quest to lean it out. The plugs are new. First ride round the hood for about a mile under 3k rpm, clutch in, coasted to a stop & took them out. Too early to tell? perhaps on the right track? Float heights are good. Im thinking still on the rich side......

 

How does it run?

How does it start when cold? How's the idle?

How does it pull throughout the revs?

 

I've always been told to put in new sparks and just take off getting the rpms up high then just shut off the engine not giving it a chance to idle. You don't want the engine to idle or be too low in rpms.

 

They are only a smidge dark, but you only rode a mile and were at very low rpms. Getting the motor fully run in and cruise around 4-5k for several miles then pull a plug and see what you get. The plug will likely lighten up as it gets hotter with higher rpm use.

 

First off you can not read plugs the way you did it and get a correct reading. Rangerscott has the right idea.

Now with that said you can get a general idea...maybe of what's going on with the way you have done it. The blackness you see may only be from cold idle with choke/enrichment on. (unless things are really out of wack) With unleaded gas you do not read the porcelain because the lead in race gas or the old days is what left the color. Instead you read the base ring and ground electrode from the heat gathered by the plug. Once a plug gets black on the porcelain from enrichment it may not burn off with normal riding. It might with prolonged high rpm use.

There is really only one way to read plugs and for most it's a real pain because of trying to get to them.

Here's a site that will explain the correct way to read plugs for tuning. It's not really practical for street use.

https://sites.google.com/site/ksmsinc/technical-info/title-3/reading-spark-plugs

 

What was included in the "fully rebuilt" operation ??

 

Perfect. Thank you very much. The bike runs better than it ever has however there is a slight off idle hesitation(time for the guitar string). Feels like bike wants fuel and finds it intermittently, then gets it above 2-3ish rpm. After that it pulls nice thru the other 2 circuits all the way up. Starts right up w/ no enrichment (in summer). Idle hangs up for a few seconds, after that holds pretty smooth at 900-1000rpm. New thread but I must add I have new boots, lubed them a bit and made sure they were seated completely. Propane gas around intakes proved differently. (Other vaccum leak locations?) Upon thinking on this, I remembered a variable that must be the culprit. The new needles and seats I bought were from a VT600 upon recommendation from the seller. Research seemed to show compatibility(yes should have forked to get OEM). To get them to work I had to bend the tangs at perhaps a 75 degree angle, to the point where they were not touching the spring button but when they did it would push them a bit diagonal first then down, which seemed dumb to me. And the micron diff between fuel flowing into bowls and not flowing is absurd. Some needles hang from thier tangs slightly different and open, some dont. Setting floats to the spec 9mm still allowed fuel to dump into cylinders & oil via 3 holes in carb throats. Even at 13mm same thing. SO I just went arbitrary trial and error and tried to get the fuel level in the bowl lower that the 3 holes in the throat using the clear tube method. The old needles have a wear ring that isnt too bad. Perhaps I should put the old back in with the proppa float height and see what happens (and get the right needles). It should way be easier and more accurate to make it work. I thought in general floats should be perpendicular to the needles. Mine are about 5 o'clock.

 

Squirrelman: New in engine- main & conrod bearings, crankshaft, pistons & rings, all tranny bearings(main & counter), some gears.
New in carbs- orings, bowl gaskets, fuel & air hose, (intake manifold gaskets were ok), new boots, new needles & seats....(the big variable!). Just posted a novel on that...

 

slides are good. needles looked ok to a semi-noob. stock jetting.

 

You are trying to read the plugs based on whats known as a Plug Chop. The correct way to do this is install fresh plugs in a motor thats already at operating temp. Then take a short high speed run through all the gears and hit the OFF switch to kill ignition, and hit the brakes. Then pull the plugs to get an accurate reading. You dont want any time on the plugs at idle, or coasting. Just the run through the gears and thats it.

 

New piston rings and new cylinder surface always need some accumulated mileage (break in) to seat and seal properly, and will allow excess oil to be drawn into combustion chamber, so your plugs colors are not so accurate at first and should not be relied upon.

Mark's (rustedroot) directions for a plug-cut probably need additional info that you need to grab the clutch lever the same time you hit the OFF-RUN switch before coasting to a stop in front of your garage or wherever you're going to pull plugs.

 

Yes thanks I didnt consider the break in period not being accurate. And big thanks for plug chop. Very good to know. I will keep updating...

 

I'd get out and get several good rides under it to get it broken in before you think about working on tune, as long as it runs reasonably well.