YZX500 Project

[scottysg]

the rest of the pics at: http://s1379.photobucket.com/user/scotty-sg/library/

Please check it out and let me know what you think! I appreciate any input you have for me

umberto I may try the lectron in the future for the reasons you've posted. I was emailing David over there, i believe he is the vp. He was very kind and helpful, so I would like to give them business if It works out. for now, as you can see in the photos in the library attached, the oem carb fits almost flawlessly. I just wish i could stretch the rubber .375 inches on top. If anyone has tips on that, I would  appreciate it. I love how I can do some metal work but when it comes to a rubber... Im just no good

The kx exhaust is way huge on the yz frame. Gonna need to cut it up so I can lower it about 6 inches and remove the stinger almost completely. I may cut a short segment from the belly. Ive been doing a lot of research and it appears this would increase the top rpm, which would give me more the small 2 stroke revability which i fell in love with as a kid and still find more fun than anything. Also interested in belly exit exhaust instead of at the end of the baffle. who knows but I'm gonna have to cut that pipe up like swiss cheese here this weekend.

[mikectanker]

Looks like it's going to be one hell of a great ride when it's done. Look up pics of the 125 air boot and compare to the 250 boot. I bet the 125 air boot will reach a little farther. Take a chance on one from eBay.  Even if it doesn't work,  you a won't be set back much.

[scottysg]

http://i1379.photobucket.com/albums/ah149/scotty-sg/IMG_1416_zpsgmxokjfh.jpg

https://www.youtube.com/watch?v=CnXQ6syZqg8&feature=youtu.be

[scottysg]

Break in done. I know my jetting is rich so Ill work on that tomorrow. Not sure the needle clip position, ill find out. right now it has a 170 main, 60 pilot, and air screw at 1.75 out. more smoke than I like. Jetting chart on this forum suggests 168 main and 58 pilot. My gearing is 13-40, weird i know, its just what I had. But I figured it would pull harder than it is so I know jetting must be off. Although, starting it is a 1 kick affair, unlike what the internet would like you to believe. definitely not getting a compression release yet. Im beginning to think 500's are more myth than anything else :\ "please let correct jetting cure my need for speed". I won't be happy until theres solid matter in my britches.

[scottysg]

Looks like it's going to be one hell of a great ride when it's done. Look up pics of the 125 air boot and compare to the 250 boot. I bet the 125 air boot will reach a little farther. Take a chance on one from eBay.  Even if it doesn't work,  you a won't be set back much.

When I finished getting everything in, the airboot was almost perfect so I ended up not needing to change it. Thanks for this tip though, I didn't know that.

[reklessj]

Looking good!!! Crisp jetting will make a world of difference. My son used to think mine was a bore, now that I got it dialed in he is scared of it. Says it stupid why would you need that much power. I say don't be little girl

[scottysg]

Took a trip to divide peak behind Santa Barbara. Awesome views. But the bike ran like hell. Moved the needle to the third position. Tried 58/168 then 55/165 jets with as many air screw adjustments as I could. If I didn't know any better I'd say it feels pig rich. Just falls on it's face blubbery after a pretty lame low end. But at wot there's hardly any smoke, so it can't be. I'm scared to go more lean that that :/ the bike idles great! Minutes more than any 2 stroke I've had. Seems crisp off idle if revving it in nuetral. Timing is good as per dots on stator. Spark looks good jumping to the block, plug is gapped to 24 thou. I'll try the "kips bolt mod" as I've seen it called, tomorrow. I hope that's the problem. If not then I'll pull the kips plastic cover and see if the arm is moving. If they're moving and I've checked for over rotation, I guess the drums could be a tooth off, so I'll have to pull the head at that point.  Out of ideas after that.

Also, I noticed a lot of tranny fluid coming out of the plastic nipple on the inside of the case behind the kick starter. My skid plate was soaked and it was obviously coming out of this spot. Gonna hook up a hose to this and zip tie the other end somewhere higher on the bike so it can drain back down. Is tht normal for it to expel so much fluid from there?

1.1 hours on the clock and running poorly I'm scared I'm gonna break this motor before it's running right.  Oh well gotta  run it to tune it  :/

[scottysg]

I have taken my main jet from 160-178 at every step and see no change in my wot performance. its unbelievable. My float valve is adjusted to spec. The carb has been thoroughly cleaned. Every port\channel is clear. I checked the power valve system it appears to be in spec. It just doesn't wanna rev or give me any power. Im on the beach and its 70 degrees. A friend suggested I check the reeds. How do these pictures look

(flashlight behind pointed right at the reed tips) Theres barely any if any light coming through the reed tips. however there is light coming around the edges as you can see. These are v force reeds, the old ones with screws holding the reeds on the block. Should I replace them or do I need to look elsewhere as to why my bike runs like a$$. Ive never had a reed issue on any of my bikes ever so I'm doubtful this matters. A 500 piston coming down should create enough pressure to close these little valves, but thats opinion only not experience.

Thanks for your help.

[Motorrad]

Didn't read the entire thread.....   But if your using a used carb... I have tried to tune several of the socal guys stuff... But couldn't due to football shaped NEEDLE jet....     (Ahem... Shlepy)....  


Edit.. Are you located on Santa Barbara? If so you may be in the "socal crew".  That gets super squirrel help and info....

[Foxx4Beaver]

Should I replace them or do I need to look elsewhere as to why my bike runs like a$$. Ive never had a reed issue on any of my bikes ever so I'm doubtful this matters. A 500 piston coming down should create enough pressure to close these little valves, but thats opinion only not experience.

Thanks for your help.

sorry if you've said you already done so...I didn't read the entire thread, but...
have you verified the KIPS are indeed working?

[scottysg]

haha interesting, ill check out the needle. Thanks for that tip. I got the carb from a guy in north dakota. I live in ventura, so santa barbara is just a cruise away. Im not sure what the socal crew or super squirrel help and info is.

I checked kips while running and the arm is moving like it should. Looking into the exhaust, the ports seem to line up right when its moved, so I'm fairly confident kips is not the issue. however I am new to kips.

Ill call around to some shops and see if I can't get some new reeds for this block. process of elimination...

Thank you,

[Foxx4Beaver]

Ill call around to some shops and see if I can't get some new reeds for this block. process of elimination...

Thank you,

these are the replacement reeds you want....

[scottysg]

Ill call around to some shops and see if I can't get some new reeds for this block. process of elimination...

Thank you,

these are the replacement reeds you want....

thank you very much! this is really helpful.

[Motorrad]

It's not the needle that is the problem... It's the tube that it goes up and down in... It is a jet. , and when the needle wears it out it makes it impossible to get fueling right....

[Foxx4Beaver]

I checked kips while running and the arm is moving like it should. Looking into the exhaust, the ports seem to line up right when its moved, so I'm fairly confident kips is not the issue. however I am new to kips.

Thank you,

this probably isn't the culprit...but,
did you happen to notice if the center "flapper valve", at the top of the exhaust port was opening fully as well, when you were checking the side valves?
over time the pins get worn and that valve won't function fully....in other words, if that center "flapper valve" can't open fully...it'll choke itself to some extent under full throttle because the exhaust port opening will be to small.