1985 Mercury 200 blackmax

[JerseyJim]

I just bought a boat with a 1985 Mercury 200 blackmax on it. It has a new stainless steel water housing and impeller, and new thermostats say the service records from last season.<br /><br />When running on the muffs, the telltale just 'trickles' until the thermostat opens up, and then WHAMMO, water comes out in force - and HOT! It wont burn you but its at least 100degrees.<br /><br />If i put my hand behind the flywheel it is only warm to the touch. <br /><br />Is this normal? The previous owner said it's run like that since he bought the motor 5 years ago. I've had smaller outboards my whole life, but this is the largest outboard me or my father have had in over 25 years

 

[robalofish]

Re: 1985 Mercury 200 blackmax

I have a 94 200HP Merc and the water comes out at trickle until the thermostats open up and then temp is 140 deg. with a constant flow of water.<br /><br />RFish >()>

 

[AndyL]

Re: 1985 Mercury 200 blackmax

The big V6 engines have huge water chambers in them and unless you have an enormous water flow through the muffs you may find that the hose cannot supply enough water to the engine. On my 135XL I can only let the motor idle on the muffs and even then the tell tale is intermittent and only spitting at best. The water that does emerge from the tell tale is hot to the touch. Your set up may be different to mine but even with the thermostats open the flow out of the tell tale is pathetic. It is OK once the leg is immersed in water and the temp is much more stable.

 

[chumbucket]

Re: 1985 Mercury 200 blackmax

Jim, Got 150 Merc and same thing with trickle. Seem's like the older Merc's are that way. Did you test temp horn ?? You on muff's or you in water running it?

 

[JerseyJim]

Re: 1985 Mercury 200 blackmax

i didnt test the temp horn yet... this was on the trailer on the muffs... <br /><br />i cracked the rear axle on the trailer yesterday so that needs to be fixed before i can get the ******* in the water.

 

[Kenny Bush]

Re: 1985 Mercury 200 blackmax

JJ, Sounds like your system is working perfectly..... Water should be HOT to the touch and barely tolerable... Thermostats sound like they are opening up good too....