1978 Johnson 200 cooling question

[raevin51]

Hi everyone I finally found an affordable engine, a Johnson 200hp. It has been sitting for the last 5 years on the back of an old Donzi. I got it Mounted and with a little effort got it to start up. The carbs are gummed up but the rebuid kits are in the mail. Now for the question. There is no tell-tale for the cooling system, does anyone know how and where to install one? Any advice would be appreciated

 

[tashasdaddy]

Re: 1978 Johnson 200 cooling question

there is a way, but on you engine i'm not sure where you do it. but it invloves drilling a hole, tapping it, and installing a nipple.

drop the lower unit, you need to do the impeller anyway. put a hose to the water tube, don't use a lot of water pressure that is up in the exhaust housing, then start the motor when the stats open you will get more discharge. if the engine gets above 150 degrees the stat is bad. stat is suppose to open at 140

 

[emdsapmgr]

Re: 1978 Johnson 200 cooling question

It should be easy. Remove the outer exhaust cover and buy one from a 79 or later model. They came with the telltale drilled. On the flatback engines, this is a pretty easy swap, exp since these older models don't have the trim box mounted on them. The original part #323360 is NLA, but is available new as #0329494. If you don't want to pay the $140 for a new one, I am sure there are hundreds of these laying around bone yards collecting dust that can be had cheaply. You will need to replace the inner and outer exhaust cover gaskets. While you have the exhaust cover off, you can check the condition of the rings and piston skirts. Make sure the rings are not carboned up and stuck, that the piston skirts don't have carbon on them.