Jetting!!! Again and again and again!

[Paul]

It all makes sense now...

I run mine at 50:1 with Maxima Super M and I don't get the smoking problem or the idling problems. I also don't have carbon build up of any kind in the cylinder or power valves. I also race this bike at that mix and I've never had a failure. I put a couple hundred miles a month on that engine.

[gowen]

Hmmmm.. Here's the problem though, because we go out riding in large groups, I share the fuel between my 250 ('97 cr) and my kx. In which both are running between C12 and Spirits (100 RON + 93 MON?). All other bikes have their mixture of pump with 32:1. I'm afriad to try 50:1 in my cr. So, I'll just make a new batch of gas for my KX and give it a shot. I'm taking this Thursday or Friday off so I'll get back with the results.

Paul, should I use Super M? I have no PV buildup in a year (just checked them) and bearly any carbon build up in the cylinder. Do you think using Castor based oils is a good idea? I do have some H1R left over, is that any good in your oppinion? I see KXCam is running H1R @ 60:1? Wow, I'm scared to even try 50:1. But, hell it might be worth it and save me alot of oil.  

[KXcam22]

Gowen,
  32:1 sure seems rich to me when using synthetic oil.  Last time I used 32:1 was penzoil mineral oil in the late '70's.  I raced for years with Belray MC-1 at 85:1 (it was the recommended mix on the bottle).  No smoke, no carbon great power and excellent cylinder longevity made me a Belray fan (fanatic?).  The only oil failures I ever had were at 32:1 with the mineral oil.  I recently emailed belray to ask why the old mc-1 said 85:1 and the new bottles say 50:1.  The answer I got was that people were leery about the lean ratio (not socially acceptable) so they changed the text on the bottle even though it was tested to be best at 85:1.  Heck, my Yamaha outboard runs 100:1 yamalube.  My '92 KX is very happy at 60:1 with H1-R, idles, 1-kick starts, and no smoke. Haven't had to clean the power valve.  I may be a Belray nut but I think all the new synthetic oils are quite excellent.  Lots of my friends swear by Super M. Try It. I'll bet your CR likes it too. Cam.

[Paul]

I ran my CR500 @ 50:1 with Super M, so don't worry about the red machine

[gowen]

I just picked up a 5 gallon can of C12, thinking I'm going to try a 50/50 of C12 and Amoco 93 using H1R @ 50:1 for starters. I'll let you guys know when I can get enough time off to ride before the weekend.  :popcorn:

BTW, doordie, what do you run in your ice racer? Knowing it is a WOT machine. or if anybody else knows..

[KXcam22]

Gowen,
 I asked a couple of the ice racers I work with. They both (CR & YZ250's) run H1-R at 50:1, winter & summer. I am interested to know what Doordie runs. Cam.

[KXcam22]

Going to try a 55 pilot this weekend.  Have been running a 58 for years but want to try it a tad leaner to see how it responds.  According to the jetting chart I am right on the verge of needing it. Cam.

[gowen]

Cam, I've done a few rides now using C12 mixed with Pump 93 mixed at 50:1 using H1R, then Benol @ 50:1 as it was the only oil I had then. I took it out to a local park and ran it hard, soft, all around and it performed well, but smoke was still pretty bad. I started out at 42 pilot, 162 main, 2nd notch. Moved down to a 160 main and it performed great and the smoke left, I've put about 10 hours on the 50:1 and no problems to speak of.

I did take it again afterwords and it was raining, humid and around 80 degrees. It ran pretty rich, and I did fool around with the air screw, which did not help the performance which I found was in the WOT range. So, I needed to move down to a 158 then, but a 160 seems to be the ticket for a nice day. Maybe a 158 would be sufficient. But who knows.

Thanks

[KXcam22]

Gowen,
  I'm still suprised that your 520 big bore requires leaner jetting that stock.  I always assumed that increasing the bore would increase the fuel demand, hence richer jetting. You and Kawadude are both leaner. What do I know.  My bike runs great but I have been slowly leaning it out a bit more. I went 168 to 165 a few months ago and noticed a nice improvement. Will try the 55 tomorrow.  How are you healing? Cam.

[gowen]

The only thing short of a 520 kit Kawdude and myself did, is I moved for topend power and he got the overall power. Which I've been told that is why I'm way down on the low numbers as for idleing.

As far as healing goes, I've been able to ride, I've been told not to ride hard and to take it easy for the next 6 months............... Right, like that is going to happen.

Thanks for asking, I'll keep updating as I fish around the carb.

[KXcam22]

The 55 worked out nice. Ran clean all the way from 1100' to 6000'. Starts 1 kick although in the cold (about 2deg C.) at 6000' I had to use the choke to start once the engine had cooled down. Suprised me at first but probably shows that the jetting is correct. Should be getting some snow to ride in soon. Cam.

[gowen]

Wow!!! It's still in the 90's here.

[kawdude]

This post is great.  It's like the energizer bunny..it keeps going and going and going.  I havent' had much time to mess with mine but I have noticed that the starting has become lousy and since Rick has built the estart conversion yet I have to fix this.  Could be the jetting but lots of gas coming out the overflow and I haven't touched the float to cause this.  Possible needle seat is shot.  Anyway another issue that I'm seeing is that when the bike does start it races.  Slide is not sticking.  Would flooding cause this?  It's odd i would have developed a airleak so quickly.  Keep the info coming.  This is a great post!!!

[mikesmith]

The weather changes and so does your jetting with it,air screw ok?

[gowen]

This is what I do, if I have to screw my air screw out past 2 1/2 turns, I go one step down on the pilot and so forth.