2002 merc

[andrewcoon]

I have a 200 mercury carb it's a 2002 and I changed the impeller and when I first started it, it pisses perfect. BUT now when I take i took it out it only pees when Ithe warms up. And at idle my water pressure is 10 psi which is good. But even with that 10 psi it still is a light **** and sometimes doesn't **** but only mists okay when I Rev it a little the water pressure gauge goes up as it should but when I plane it out it goes up to normal but then goes right back down to 10-11 the thing is last trip out it pissed after 30 seconds and at wot had a pressure of like 20-25 psi.. now it takes until 140 degrees to pee. And has good idle water pressure but low wot pressure. Also does not get over 160 degrees. I'll get a video soon.. thanks for the help sorry this post may not make sense I'm typing this on my phone

 

[andrewcoon]

Bump

 

[rangerfscott]

i have the exact same motor you have. 10 psi is what i normally read on plane WOT. at idle it will be around 2 or 3 psi. as far as the stream you may want to remove the cowl and look at the back where the hose attaches to the fitting that the water streams out of. i had a pinhole in mine once and it looked like i wasn't peeing a stream but it was actually leaking inside the cowl. or the fitting could be stopped up. if none of that is the problem then change your thermostat. and also make certain your high temp warning horn is working just in case you do have a over heating problem hopefully it will let you know before you ruin the engine. good luck.

 

[andrewcoon]

I think you might have an issue I had a leak to my gauge and I have 10 at idle and 20 at wot.. is it on a bass boat

 

[rangerfscott]

yeah its on a stratos and never had a single problem with it. now i need to add that i have it jacked up on the jack plate to get more out of the water. when i had it lower down my pressure was higher. you just have to be careful when playing with the engine height or you can get the pickups out of the water. thanks.

 

[enginepower]

I have a friend with a 200 merc, his doesn't pee until it warms up as well. He said it doesn't pee until thermostat opens. I would think it should pee all the time like somewhere there is a bypass around thermostat to allow water pisser operation tho.

 

[andrewcoon]

After further research and watching a lot of YouTube videos, it does only pee when the thermostat opens, which will take until 120 degrees