What do reed valves exactly do??

[jono_uk]

bit of a newbie question i own a 1978 9.8 mercury blueband and the reeds are sittuated on the crankshaft does anyone know exactly what they do as i got a prob with no fuel getting to plugs. the compression and spark is good

 

[4.0l sahara]

Re: What do reed valves exactly do??

They are like the intake valves on a 4 stroke just they open when there is a vacume in the crank case. No cam etc. They alow air/fuel in.

 

[JB]

Re: What do reed valves exactly do??

Check out "Outboard won't start" in the Engine FAQs, jono.

Sounds like you have a carb or fuel supply problem.

 

[Motor Boater Bill]

Re: What do reed valves exactly do??

What reed valves do:
Open
Close
Open
Close
(repeat)

Sorry, couldn't resist...

 

[j_martin]

Re: What do reed valves exactly do??

What reed valves do:
Open
Close
Open
Close
(repeat)

Sorry, couldn't resist...

At six grand, mine don't bother to close.

Also sorry

 

[jono_uk]

Re: What do reed valves exactly do??

Check out "Outboard won't start" in the Engine FAQs, jono.

Sounds like you have a carb or fuel supply problem.

i have followed everything in there i have even replaced the carb for a different one and some guy from mercury reckoned it maybe a prob with reed valves or a cranckase seal just thought id check to see any other ideas which it maybe before i throw anymore cash at it

 

[rickdb1boat]

Re: What do reed valves exactly do??

If the reeds are good, then fuel will get though to the cylinders if there is enough compression (Vacuum) to pull it in. If any of the reeds are broken, you will get more fuel into the cylinders. A clogged carb would be the first suspect. Shoot some pre-mix into the carb throat and try to start it. If it trys to go, then you have another bad carb..