Clogged Cooling System on 1998 200 Johnson

[Jaker34]

Hello,<br /><br />I recently ran my enging in shallow water and noticed my water flow indicator was showing a reduced amount of water being pumped. I imagine this is from sand getting into the cooling system. What is the best way to clean the water passages and fix any cloggs in the cooling system?<br /><br />Thanks for your responses.

 

[steve forsythe]

Re: Clogged Cooling System on 1998 200 Johnson

I would like to ask the same question. I ran my 200 Merc in some shallow sandy water a while back and stirred up a lot of sand. Had a powerhead failure not too long after...Hmmmmmm? What can i do to check???

 

[Pursuit2150]

Re: Clogged Cooling System on 1998 200 Johnson

On the johnson the is a hose attachment, located at the tell tail outlet. Reverse flush the engine,vetrical position, engine not running and see if the reverse flush will clear out the muck. You'r owner manual should have the instructions.If that does'nt help, then the impeller is probably shot.

 

[clanton]

Re: Clogged Cooling System on 1998 200 Johnson

On the Johnson, pull the thermostats and pressure relief valve,engine in water start engine,water should gush from heads, will take a few seconds to fill block, block holds about 5 gallons. On the Merc just pull thermostat.<br /><br /> On the Merc the pressure relief valve is down on the STB side of block, if it leaks or the seat is bad, water pressure drops in the block. I would also install a water pressure gage.

 

[Pursuit2150]

Re: Clogged Cooling System on 1998 200 Johnson

Clanton- I'm just curious why go to that trouble, on the Johnson, when the flush attachment is there for the purpose of cleaning the system out.

 

[clanton]

Re: Clogged Cooling System on 1998 200 Johnson

You dont have to remove the thermostat if the flush attachment will clear the water passages, but it will not always clear, shell, chunks of inpeller, or other trash around the thrmostat. I also understood he said sand.

 

[Jaker34]

Re: Clogged Cooling System on 1998 200 Johnson

Yes, there was sand and shell fragments in the flushing port when I removed it. I flushed the engine, and there was slight improvement. I assume I can get the rest of the fragments from pulling the thermostats. Thanks for your help.