Jetting!!! Again and again and again!

[livenlife699]

Hmmm Def got me thinking! When I swapped from the 168 main to 175 it ran better both down low and up top so I was planning on trying a 178 or 180 main with more adj on air and smaller pilot? I will have to say that I officially hate jetting! lol

[Motorrad]

Hmmm Def got me thinking! When I swapped from the 168 main to 175 it ran better both down low and up top so I was planning on trying a 178 or 180 main with more adj on air and smaller pilot? I will have to say that I officially hate jetting! lol

I didnt read your first post..

But if your motor is stock... with that jetting (178)... somthing is up.
Float hight... or air leak..

Ive seen it many times... guys Jetting their bikes... thinking their jettings wrong.. when they are only compensating for other "issues"  (air leaks)

[jonny500]

so do i. i wasnt saying you should go down i just thought i would add that info to the thread. if your engine is running better as you go up in jet size then go in that direction. 168 main is standard so 180 is getting high. what altitude and temp are you at, are there any air leaks

[livenlife699]

Where should I check for leaks? Only place I could begin to think is the airbox to airboot..I did seal it up but maybe Its leaking air..The bike sounds good until I give it full throttle it loads up but loads up less than it did with the 168.

[livenlife699]

Motor has Wiseco +1 Piston,Port and Polished Cylinder, Vforce3 Assembly,FMF gnarly exhaust with powercore 2 silencer, 40:1 with 175m/58p 2ndclip on needle

[Motorrad]

Where should I check for leaks? Only place I could begin to think is the airbox to airboot..I did seal it up but maybe Its leaking air..The bike sounds good until I give it full throttle it loads up but loads up less than it did with the 168.

Leak Down test.

[livenlife699]

Allright well im going to look into that as i have never heard and will be playing with the bike over the next few days after work, I might end up just taking it back to my engine builder due to having the motor built before my chassis was ready so here I stand with a complete bike that runs 95% lol

[livenlife699]

Can anybody help me out with a general point of reference on cleaning up my top end? Will going to a smaller pilot and in on the air screw help? I still have yet to get it 100% and am a little lost :/ I have a 175main with 58pilot on the 2nd clip from the top 40:1...

[sniper1]

       Just wanted to say that the graph is dead on for my setup and I thought it would be good for me to share my setup with everyone in case someone else has the same setup and needs to get their jetting right.

      I have the gnarly pipe with boyeson 2 stage pro reeds (carbon fiber) with moose spacer on the carb side instead of against the jug I have a custom 8" pro circuit 304 silencer the bike has 14/47 stock gearing I run 94 octane fuel with amsoil 2 stroke oil.

      I am in southwest michigan at 1200 feet above sea level and it's 80-90 degrees outside I mix my oil and gas at 32 to 1 because a properly jetted bike runs great at that mixture and runs at the right temperature in my experience.

      I have a 165 main jet with the stock needle in the 3rd clip position or middle and a 58 pilot jet I tried a leaner pilot and it kept cutting out and running real hot and I tried the 60 and it was sluggish same with the main I tried the stock jet it was fat or rich and tried a 162 it was lean and ran hot so for this type of bike with these aftermarket mods this is the setup just like the graph says it should be.

165 main jet
stock needle middle or 3rd slot
58 pilot jet
amsoil synthetic mixed 32 to 1
58 pilot jet
amosil synthetic mixed 32 to 1
air screw out 1 3/4 turn
idle screw is  turned out 4 or 5 turns and the bike idles perfectly nice slow idle


I should mention that I installed the boyeson 2 stage pro reeds in the stock reed block with sock reed stops because I've had rad valves and never liked that when hot it would get reed flutter at high rpm with no reed stops and it would even suck a reed when run real hard from time to time

I have instant throttle response from this bike and it pulls very hard all the way to max speed where it finally runs out of gear and the spark plug is a perfect chocolate milk color after a few throttle chops, I know that this is the way a 500 should run and this bike has the original stock engine and it's a 2002 model year so imagine how it would run with some engine work or even a fresh engine but I bought it from a older gentleman that was the original owner that is why I know it's the original engine.

Nice article

http://twostrokemilitia.jfn3.com/tech_articles.html

[KevenW]

I'm new here and just bought an 03 and it's running awful! Surfing really bad and not clean at all. Haven't done any throttle chops yet. That seems to be key to proper jetting. Engine is stock, even the pipe. I'll update after some throttle chops when I get time.

[Uncle pirate]

Always rem that smoking on a two stroke is usually related to the premix ratio...and from experience the"factory recommendations" for such are to save the factory from having to honor any form of warranty-implied or otherwise...when we raced, we ran castrol at 50-1,with no major wear issues...of course we were doing strip downs every other race,so we could keep an eye on any potential issues. Consequently, I consider 32-1 a max oil ratio,anything greater usually just means replacing fouled plugs(I don't like running too hot of a plug-and bp8es to drop the electrode deeper into the dome-it clears the piston and theoretically creates a better flame front...)when we ran (factoring recommended)20-1we usually couldn't make it thru a moto w/o fouling. I'm running team green specs w/168 mains...BelRay synthetic@ 40-1.plug runs tan-no oil fouls...of course I'm at sea level now,so a rejet is in order and I'm no longer running in 100+temp days.Im assuming (the smoke)is blue and not black of course...

[Motorrad]

given....... I havnt read MOST of this thread.   but I havnt seen anyone discuss how premix viscosity affects jetting...  

[sandblaster]

Come on someone.... Bite..... He's trying to set the hook.... 

[SHLEPY]

The thicker the goo the slower the motion.

[Motorrad]

The thicker the goo the slower the motion.

thats what she said.