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First off dead stock 650sx engine.
I had posted earlier about this earlier at http://www.pwcforum.com/vintage-jetski/4737-top-speed-650sx.html
It runs/ idles great but once you fall off and it circles around as soon as you grab hold of it it sputters and stops. Believe the idle is too low to take the extra load of pulling it's own weight and ME to boot. The idle thumb screw is maxed out, clockwise.
It also tops out at 36 (GPS on my F-12X).

Someone on this forum told me to adjust the hi and low jets.
For one there is only 1 jet.
I'm a newb to jet ski maintenance but not to carbs, see my 68 Vette on my homepage.
Looking low on the carb body a single brass colored flat tip bit is sticking out from the carb body. I tried to adjust the idle at the beach but the wake was so bad I could not hold onto the small screw driver to fine tune anything as the ski was bopping around in the surf. Adjusting last night on the trailer with flush line connected I adjusting the jet and there is no immediate change in idle, you have to wrap the throttle several times to see any change. So from dead closed to two turns counter clock wise open gives it about 1500+ rpm (guestimate) and then decreasing the idle thumb screw to open halfway gave me 500+rpm (guestimate) so I can now adjust the thumb screw on the lake, hopefully no wake, with the load on the engine from the water, to fine tune the idle.

I see NO high speed idle. Above the low speed jet is 2 phillips head screws, one is a part of the carb body and the other is not tight but completely shut and turns only 1/10 counter clockwise and springs back to full shut. This appears to be a return spring screw and NOT a jet so I have no way to adjust hi speed.

Please let me know if I'm screwing up and let me know where the hi speed screw is. I deeply appearicate any help you can give me.
 
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