Did some plug chops and jetting tweaks...

Micahdawg

Member
Feb 2, 2001
503
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If you read this Rich, I picked up a handful of BR8ES's at the local shop and hit the trails this weekend. I got the bike warmed up and took it out to a straight section of road right off the trails. Put the new plug in, putted down the road and came back WOT in 3rd and WOT in 4th....then cut the ignition.

When I got home to inspect the plug I found a 1 mm thick dark carbon ring but it was only dark for about 1/4 the way around the plug. The rest of the way was a light brown hint of a carbon ring just as thick. Plus the dark section had a little wave to it.

I went back and tried the chop again with another plug only this time I rung it out from 1st through 5th and once I hit top speed and pinned I did the chop. Found pretty much the same thing. Only dark for a very small section, then light brown the rest of the way around.

My jetting is 162 main, need second clip from top, 99 octane Klotz 32:1, temps were dry and about 85 degrees out. I'm thinking I might go back down to the 3rd clip on the needle. The bike smoked and spooged worse on the 3rd, but didn't seem to run worse.

Also, I followed Spanks jetting procedure and got the bike warmed up with a fresh plug, then carefully turned the airscrew out (starting from 1.5 turns) until the idle reached the highest point. The idle picked up higher and higher until the screw was all the way out (2-3/4 turns out). According to his procedure, that means my factory #48 pilot jet is still too rich?

One annoying thing the bike was doing is if I'm at idle in neutral, the bike will purr like a kitten. If I barely crack the throttle open (1/8th) the revs jump ALL OVER the place---chopping, cutting, up and down. Could this be loading up from too much fuel? I sat still holding the throttle at this point and carefully adjusted the choke knob from closed to 20 clicks out.....also adjusted the air screw from closed to all the way out and couldn't EVER get the irratic chopping to go away (except with the airscrew totally closed and then it would load up and be hard to keep running).

Micah

P.S. Mid range feels good....then a little flat spot into a pretty good top end.
 

Rich Rohrich

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Keep in mind all you are reading with this method is the main jet at WOT. The rest of the settings you'll have to figure out by the ride and feel method.
 

Micahdawg

Member
Feb 2, 2001
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Right....the main jet is all I was looking for with the plug chop. Does it sound like I'm not riding it enough at WOT before cutting up the plug, or would you say that my findings are indicative of a lean condition. It would have been nice to see a uniformly dark ring around the base.

Micah
 

Rich Rohrich

Moderator / BioHazard
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Jul 27, 1999
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From your description it sounds like you are safely rich (maybe too rich) on the main jet.

Now you can sort out the rest of the circuits and then go back and recheck the main.
 

Micahdawg

Member
Feb 2, 2001
503
0
Thanks for the insight. Also forgot to mention that I repacked the silencer this weekend to eliminate that concern.

Micah
 
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