I was just wondering after doing mods, what is your opinions on plug reading.
IE....
How long to wait after doing a mod?
Should you just let it idle?
Should you ride it for a little while or just park and go through the full rpm range?


What is your opinion let me know.

 

Ive always been told to install a new plug and hop on the bike, ride it in an open field and open it up wide open as you go through all of the gears. Then kill the engine, remove the spark plug and get your reading.

 

i am a firm believer in tuning off the plug. i don't know what bike your tuning but, if its a 2stroke its absolutely important after modifications to look at your plugs. what i do is let the bike idle 10, 15 mins. if the mod you did effects the idle wildly then obviously you should not go romp the gears. shut the bike off use a pair of cloves and pull the plug and look it over. if the plug looks good. DO NOT CLEAN IT OFF!. put the plug back in and let the bike run back up to operating temp. pull through the gears as you would when your riding, constantly varying rpm. make a few pulls through all gears. and pull the plug right away. and read it. once you understand what to look for you can start tuning for performance... just remember richer you run, less down time your bound to encounter!

 

I've been reading plugs for a loooooong time. It is virtually impossable to read a plug without lead in the fuel. You can, but it takes forever to color the plug. If anybody does not believe me just do this test. Take a good running quad and pull the plug. Put in a new plug and do the test like Raptor450 suggests. See that pure bone white plug? Looks lean don't it? Now leave that same plug in there for a days ride. Pull it out. See the slightly tan color? Right on the money now ain't it?

Race gas is a different story. Do what Raptor450 suggests and you will be good to go.

 

well its going to be my 450 wolverine, so a 4 stroke automatic running on premium

When I ordered the 488 kit from FST, I asked what he suggested on jetting and he told me to just go up one size on the main(im only jumping up 67cc and from 10.5 to 11.0:1 compression).

I have never done a whole lot of modding on my past quads and this is the first thing that I have done major that would require a rejet (other than the pipe and filter, which dynojet had figured in and recommended the proper jetting)


So if anyone can tell me a little more on the spot info I would appreciate it. Sorry for not providing enough info earlier.

 

<div class="FTQUOTE"><begin quote>Originally posted by: ctateusa1

well its going to be my 450 wolverine, so a 4 stroke automatic running on premium



When I ordered the 488 kit from FST, I asked what he suggested on jetting and he told me to just go up one size on the main(im only jumping up 67cc and from 10.5 to 11.0:1 compression).



I have never done a whole lot of modding on my past quads and this is the first thing that I have done major that would require a rejet (other than the pipe and filter, which dynojet had figured in and recommended the proper jetting)





So if anyone can tell me a little more on the spot info I would appreciate it. Sorry for not providing enough info earlier.</end quote></div>

plug runs get easier and a little better with practice but heres the basic run-around. Ok with the real plug run im going to tell you your looking to test the correctness of the main jet, you dont want the idle jet interfering with your reading. Now most of the time I do this on a fully manual but an auto should be easy too, the hard one is the semi auto with gears but no clutch. So on a manual you line up on a strait road or strait field. you give it full throttle and run at max RPMs for at least a few seconds, then at the same time you cut the engine and pull in the clutch (or in your case put it in nutral (so the wheels aren't turning over the motor hence pumping fuel that wont be burned. Now when you come to a complete stop your plug reading should be representative of your jetting at WOT (wide open throttle) or totally on the main jet. Now you take the plug out and lood at the "L" that comes over the plug and the thing in the middle itself. (sorry i have no clue their official names but that should convey my point. The standard jig, very light tan or typically white spots (covered white in some cases) means a lean condition. whatever you do you DO NOT want LEAN. That means there is too much air and not enough fuel. Most people agree a correctly jetted bike when checked on a plug run should be a golden to tan, and pretty much dry. this would be a good jet. Now a rich condition will be dark to black and if rich enough will start to be wet or even soaked in fuel. now because 2 strokes burn oil with their gas their jetting is more finiky and you can "foul" a plug (which is when it gets gummed up with unburnt premix) much easier, although a 4 stroke can foul a plug too. Remember, the most important thing is that your bike is running well, and not lean. So if your bike is running amazing and you check the plug to find its not tan its dark. If your not having any problems dont mess with it. if its lean on the other hand you run the risk of the piston getting hot and melting to the wall of your cylinder (bad thing) basically other than not lean (white spots/light tan) if its running good your good to go but its a good gauge if your plug is dark and damp you can lean your mix up a bit and may find the motor wasnt running as well as it can

forgot to add: as far as how long you should wait to plug run and re-jet it should be right away. Plug will show evidence of lean/rich condition right away. If plug was really really rich before mod (and you should check your plug before you do a run just to see where your starting at) it cant hurt to throw a fresh one in they are only a few bucks... I always keep a few spares around anyhow. If you get it dialed in right and it was running on the old plug can throw the old one back in if its not too old