Ski tries to fire now and then, but won't start. Help!

[AWolf34]

Finally finished my build and ski won't start. It'll try firing now and then, but just wont start. Even when you dump gas down the carb. Compression is perfect. I've tried switching carbs off of a good running ski, swapped coils, cdi/ entire e-box, checked the stator with an ohm meter and it's all within spec, timing is good (so the lines say), and I've even tried bypassing the start/stop switch. Im running a ported 701 62t/61x, ada girdled head (33cc domes), single riva 48 carb (no reeds), riva red pipe (sadly), and 61x electronics. I've already pissed more than half of the season away saving money and building this thing. I just want to ride. I'm cursed when it comes to this sport. Any help or ideas would be greatly appreciated. Thanks. Oh and motor ran strong when it was pulled out of the previous owners ski. It came complete minus the 62t electronics he was using. Im stumped....

 

[superjet104]

Compression??


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[102nd7]

No reeds? I'm pretty sure that's a must on the yamaha based motor

 

[AWolf34]

Spot on

 

[AWolf34]

Thats something i was contemplating. Ive got a good set i can throw in and try

 

[102nd7]

I'm 100% positive you need them. I know I had a Reed fail on an old 701 and it ran like poop hard to start and missed like crazy. Put them reeds in there

 

[JetManiac]

You have no reeds at all?

 

[tor*p*do]

gotta have reeds

 

[Sparkplug]

Op was joking right?

 

[AWolf34]

Nope. No reeds at all. And i should have known better when i checked that, but ive seen some motors that dont require them. Anyone know if 61x reeds will fit in 62t?

 

[102nd7]

They will not

 

[AWolf34]

Ok thanks. I really appreciate all the help guys. Time to go hunting. Ill post the verdict once i get some installed

 

[AWolf34]

Well durrrrrr. Of course it was the reeds! Fires right up. Wish i would have been informed that they were removed when i purchased the motor.

 

[102nd7]

Congrats

 

[Tyrant1919]

Live and learn. Without the reeds, the air that's supposed to be going to the cylinder from the crankcase as the piston comes down instead goes straight back out the intake.