Ski suddenly running really flat

[DylanS]

Update:
No better
Ski is getting parted out when I get back from this trip
Bolted buddies 49’s on and it runs like a champ
Something I’m missing with these carbs

 

[Pro-pulsion]

Not sure if I overlooked it but did you mention what carbs exactly you had on it before the 49's? Also one area to look at for air in the fuel just a generally overlooked item is the fuel valve. They typically are sealed only by an o-ring inside and I have seen them wear out and start pulling in air. This may not apply to your ski if you don't have a fuel valve but in case anyone else is reading this and having air bubbles in the fuel line. The fuel lines can also be leaking on the shutoff valve. If they're the transparent poly-lines they will eventually dry out enough to become stiff and no longer seal but act more like a slide fit spinning around the hose spigot. But yeah, if you could remind us of what carbs you're running that might help with the more experienced guys to come up answers. It could be a specific thing to a specific style of carb.

 

[DylanS]

Not sure if I overlooked it but did you mention what carbs exactly you had on it before the 49's? Also one area to look at for air in the fuel just a generally overlooked item is the fuel valve. They typically are sealed only by an o-ring inside and I have seen them wear out and start pulling in air. This may not apply to your ski if you don't have a fuel valve but in case anyone else is reading this and having air bubbles in the fuel line. The fuel lines can also be leaking on the shutoff valve. If they're the transparent poly-lines they will eventually dry out enough to become stiff and no longer seal but act more like a slide fit spinning around the hose spigot. But yeah, if you could remind us of what carbs you're running that might help with the more experienced guys to come up answers. It could be a specific thing to a specific style of carb.

it’s a set of first gen 48 full spectrums, I’m starting to suspect a crack somewhere but I’m going to put a complete rebuild kit on both carbs and try them on a new motor. Have been through them 10 times with several other people and can’t get my finger on them. Also had all new fuel lines on a new pickup that holds pressure.. still getting air in my lines..

 

[DylanS]

Check the Throttle Shaft play and Bushings. When they wear out, Air starts to leak/rush past the Throttle Plate Shaft Edges instead of over the Plate at the 12'Clock which is where the Fuel Outlet Holes are.

When the Throttle Plates are closed shut, there should be no daylight at the Throttle Plate edges on the Shaft.

When this happens, the Carbs no longer meter Air correctly and will run erratically.

Maybe it's time to rebuild the complete Throttle Shaft Assemblies. Make sure you note the Number engraved on the Plates and order accordingly.

Very well could be an issue, they seemed tight but they are getting there for sure. Will rebuild them too and update when I get the new motor together!

 

[rob-noten]

Any news about this ?