1995 Mariner 50hp - Carby missing Vent and Main Jets.

[Tyfab14]

Hey folks,

Finally got my hand semi ok and managed to start working on the engine again yesterday.

I changed the trigger and CDI. Since then, the engine works really good but now idling at neutral is around 1000RPM.

I went to the boat ramp and tried (without manual) to tweak the idle but it either too low and bog down our too high and prefer not to put in gear.

I bought the service manual and realised that the vent and main jets are missing on the carbies. (never noticed before... and always worked well without it)

What's the purpose of these screws?



Will redo the timing and Carby sync as the manual is very detailed and easy to follow. Waiting for the timing light to arrive from SCA.

[Noelm]

You sure the main jet is missing?

[gazza2006au]

Ty carburetors are often used on many other engines of all sorts some have the external mixture screw lugs but they are blanks, some carburetors have the jets inside the carby bowl and some have the mixture screws externally under the carby bowls

you engine wont run without its mixtures screws in place

[gazza2006au]

Thought i deleted this post ah well

[ericcs]

mixture screw and main jets are very different to each other. i doubt you can tell if the main jet is missing without pulling the bowl of the carb. easy to see if the mixture is missing!

[stevej]

Wouldn’t even run without a main jet as the fuel flow would be too great

[Tyfab14]

I am talking about these screws

Attachment 119482

[Cox76y]

Link doesn't work..

[gazza2006au]

Ah i don't even know what i was thinking with that post.... i think your talking about the jets in the throat of the carby some have some some don't your main and idle jets are in side the carby bowl, i think i added in the mixture screw because your idling high sounds like the mixture is lean

[ericcs]

if you still can't get the idle down, i can only think the timing is too far advanced!

[Steeler]

Has anybody screwing around with the throttle linkage ?

[Tyfab14]

Right!

I received the timing light and service tachometer, Went to the boat ramp and managed to get her back to spec! Works perfect!

Happy days - thanks for your help.