Changing Reed Valves on an 850 Mercury

[OhNoMrBill1960]

I recently aquired an 1974 850 Mercury 85HP inexpensively. It was in a guys shed and he said that it was running when he put it there but quit using it because it was stalling and wouldn't idle properly he figured it needed reed valves. I am not saying he is right. But if so is this a big undertaking to change them, does it involve opening up the motor gaskets etc. Any help would be appreciated.

 

[shelbydriver]

Re: Changing Reed Valves on an 850 Mercury

I believe reeds are easy you just take of the carbs and or leave them on and take off the intake manifold to get to them. Get a manual for the motor. Good luck. Try the boysen power reeds for better throttle reponse ect. I think about a 150 dollars! Bobs machine shop bobsmachine.com

 

[ledgefinder]

Re: Changing Reed Valves on an 850 Mercury

The reeds on the older Mercs are wrapped around the crankshaft - total disassembly to get at. <br /><br />However, not at all sure the reeds are bad from what you describe. How about getting it running on a stand, then post back & describe any problems?

 

[OhNoMrBill1960]

Re: Changing Reed Valves on an 850 Mercury

Thanks all. I think it must be that the reeds are on the crank as he said that himself. And he is mechanically inclined. <br /><br />Any idea of the costs associated with doing the reeds. Just curious.<br /><br />Thanks again

 

[Hooty]

Re: Changing Reed Valves on an 850 Mercury

Most reeds are made of metal and usually when they break, they tear up something else like pistons and cylinder walls.<br /><br />c/6<br /><br />Hooty