Picked up Kawalski yesterday morning. The mech says the valves look brand new. Not even a piece of dirt in them either, well within the clearance spec. I guess all the low-RPM street crawling I do must be babying the motor. I'm VERY excited that at 9000 miles my engine topend looks brand new

He pulled the plug and according to him, the bike is running very lean. ??? I've got a Dynojet 128 main, the DJ needle on the middle clip, and the A/F turned out 2.25. I thought I was running it rich. I'm running 93 octane, would this be a factor? Is it true that the plug-test isn't very reliable on modern four-strokes? He suggested throwing the biggest jet in it that I have (which is the DJ 132 which came in the kit). He also suggested the stock needle.

Opinions?

Its not that hard to get to it so I figure I may just throw that 132 in it and take the lid off for giggles... yeah MPGs will go to turds... but MORE POWAR... I'm just worried that it would be TOO rich with a 132.

And for those of you who were curious: He showed me the old camcover gasket. He didn't tear it, it indeed had shrunken up as others have had happen. I'm very happy.

Now time to RIDE!

And oh yeah... when I picked it up, I went straight to the gas station, filled it up, and took off

I took this pic yesterday in the exact same spot I took the same pic a year ago:

One year ago:


And yesterday:

 

Glad to hear your mule is back on the trail. Happy times.

 

glad ur back in the saddle again bro! let the good times Rollllllll

 

Glad you're bike is back. I would not go back to the stock needle, that's the whole point of the Dynojet kit is the needle. Are you running airbox lid on or off or modified? Getting it jetted correctly is a process, hate to say it but you're just going to have to experiment. You might get lucky and happen onto the perfect setting first time, but that would be unusual. What clip position are you using with the needle? If you really think it is running lean with the 128 and 2.25 out, I would try as a reasonable baseline - pull the airbox lid, just remove it. Try the 132 main jet, needle on the 3rd clip, and set the fuel screw to 2.5 out.

But if it was running good in cool weather and now its not in hot weather, then chances are you are now too rich. I wouldn't pay much attention to the plug from the mechanic. For that to be reliable, you have to do a "chop" I.e., go WOT, then immediately hit the kill switch, pull the plug and take the reading along the side of the road. I seriously doubt he did that.

That doesn't mean it's not running lean, though. Sometimes when the jetting is close, the difference between running a little lean vs running a little rich is hard to tell. What I've done in that situation is put the airbox lid on, is is better or worse? Take the lid off, is it better or worse? Since putting the lid on will effectively richen the mixture (less air + same fuel = richer), that will help you determine which way to go on the jetting and help answer the question of whether it is a little bit lean or a little bit rich.

It's a process. Good luck.

 

That's what I thought... I know my dad said that's the big deal of jet kits is the needles (he has the JD Jetting for his DRZ). I'm currently running with the airbox lid on and the snorkel removed... needle is on the middle (3rd) clip. I know back in the spring I tried running with no airbox lid and it felt like it surged especially at 3/4s throttle then if I let off... like a lean condition. That's why I thought the 128 was dead-on.

IMHO the bike runs fine, its just a bear to start if I crash in the woods or it gets really hot in the woods. I've been told that's just the nature of our bike; combo of no hot-start circuit and CVK, etc. But riding around town today in 100 degree weather it feels fine... smooth throttle response, very peppy, feels great.

I'm seeing all the guys on here running 124 main jets with stock exhaust and I'm already running the 128 with stock exhaust... I figured I'd be rich if anything.

I think I"m just gonna leave it the heck alone. I think if I was dangerously lean (as in, cook a piston lean) the bike wouldn't run right, as in, it would surge, etc. The fan rarely cuts on, so I mean, I doubt its super-lean...

 

Maybe someone can chime in on this, this just an observation I've made. I think plug reading were more accurate for air cooled thumpers and two strokes. I bought a brand new YZ426 in 2001 and ran it around at 7000" elevation with the stock sea level jetting for a number of months before I got around to jetting it for that elevation. I remember pulling the plug when it had the original jetting and it had what I would call a definate white/grey "lean" color to it. When I changed to a smaller main and idle jet and lowered the needle the bike definately ran better with much improved response. And as I expected the plug still looked lean. I still have the bike and it has never had any engine maintenance other than valve clearence shim adjustments, air filter cleaning, and oil changes and it still runs great. So I'm just not sure that plug readings mean all that much any more on current L/C 4 strokes. The plug on my 07 crf450r is the same way and same with the KLX. They always looks lean. Haven't blown one up yet.

 

132 rocks, and throw the lid away. And sometimes you do get it right, or at least that's what the mechanic said when he handed my bike back to me over 10,000 miles ago. Yee Haa

 

Cliffsta, you're running pretty much the same setup I am. We're both at sea level, although I'm sure it's hotter in LA (we're at about 80'F, 80-100% humidity right now. My bike runs great, and although, if I stall it in the woods, I have to give it a little throttle to restart it, it hasn't really been a problem. I think you should keep what you''ve got. Maybe adjust the A/F screw a bit but I wouldn't worry too much if it's running well around town.

 

Glad to hear that you are back in the saddle

 

Yes, and no.
Its not the modern 4 strokes, it's the modern fuels.
Gas is a lot different than it was when this was an established practice.