Do you recommend replacing the choke with a prime?
I never recommend installing a fuel primer! Because if you did, you might
fix the symptom (hard starting) but the mechanical problem will still exists.
Your problem occurred after sitting, did you or a mechanic rebuild your carb
last year (2018, or 2017)? If so, the float diaphragm may be stiff. This can happen
because the aftermarket rebuild kits don't stand up to the ethanol in our gasoline.
Did you ever replace the stock spring?
Has the engine ever been rebuilt or new main seals installed? (The SX Reed 550,
had the best 550 main seals)
Have you reused the reed gaskets?
Keihin (oem) rebuild kits cost ~$85, and so many people choose to pay less $$.
But the oem Keihin rebuild kits last longer because the manufacture took time
to do ethanol testing with their products. So in the long run, oem cost less $$.
Keihin carb base gaskets leak vacuum after 1 use, so I would expect the low speed
(pilot) screw setting to change after reusing a carb base gasket.
The OEM carb settings no longer apply to your ski, because of the 550 is old.
I recommend you look at my pictures, and make a flat sanding fixture with a
piece of glass ~3/16" thick, 220 or 320 emery cloth, and 3M spray 77.
Bill M.
A few other details:
Diaphragm carbs don't like to start with a high idle.
When you choke the engine, pull the choke and hold it closed, and with your
other hand apply the starter. Don't touch the throttle until the engine pops.
Then crack the throttle and start the engine.
After the problem is repaired, set the low speed (pilot) screw using the
"Idle Drop Test."
