Reed Valve ?s

[michaud500]

I have a 1969 Mercury 500, #2629264. The fuel systems completely rebuilt 10 years ago and ran non ethanol gas with Mercury 2 stroke oil at 50-1. I haven't really used the boat for a couple of years now and am wondering about rough ride and running issues. The plugs from the lower carb #3 and #4 cylinders don't seem to have any carbon build up to them after running. Compression on all plugs is around 114-115.

The question that I have is should I run Seafoam to clean everything out good? Or should I check the Reed Valves?

If the Reed Valves how do I check them and is it possible to replace them without taking the power head apart?

Sorry for the rambling..

 

[racerone]

Reed valves are way inside the motor.----Near total tear down required to replace them.-----Doubt it is the reed valves.-----Does the motor have full power , yes or no.-------You could have water leaking into the 3 and 4 cylinders.----Or lean on fuel.-----If boat sat for a few years with fuel in the carburetors you must remove them and clean them.-----Failure to confirm that jets are clear and clean can risk big $$$$ damage to your motor !----Always run fuel out of the carburetors when boat is taken out of the water !

 

[tpenfield]

Let's see . . .

run seafoam or check the reed valves?

I'd run the seafoam . . . maybe a concentrated mix. I've run 25-35% seafoam, just to clean out the fuel and intake system.

 

[flyingscott]

Seafoam is fools gamble. The proper way to clean a carb is.tear it down and clean it.completely. Seafoam can be used to soak it in.

 

[GA_Boater]

Check spark on all cylinders and compression. Rebuild the carbs. Those are the first 3 things I would do.

Adding - Change the impeller.

 

[michaud500]

Thanks guys

I have spark at all cylinders and will have to take her to the water as It doesn't seem to be pulling much water from the water muffs(will replace impeller). What about this spray from Mercury to clean out carbs(saw it on a different post) people swear by it? Seems like a gamble also with the fuel being both a lubricant and a fuel source.

Will keep you posted

Thanks for the input

 

[flyingscott]

The carbs must be torn down to clean correctly no mechanic in a can for that

 

[Scott Danforth]

Thanks guys

I have spark at all cylinders and will have to take her to the water as It doesn't seem to be pulling much water from the water muffs(will replace impeller).

impellers only move water, they dont "pull" or "suck"

 

[michaud500]

So I took the boat to the lake, reset the idle screws and she started great, so I drove around for about an hour at various speeds. When I was at mid throttle the engine has a rattle inside the cowling and the motor would shake a bit but as soon as I either slowed it down or opened up the throttle these symptoms would go away . Also had a hard start issue. Any ideas as to what that is?

Thanks again

 

[racerone]

It was suggested to you to install a new impeller.----Did you follow that suggestion ?-----Are you saying it started great and now it does not ?