tattle tale

SparkieBoat

Captain
Joined
Aug 17, 2009
Messages
3,643
Re: tattle tale

I think the water pressure should be around 7-9 PSI at idle and around 20 at WOT..
 

will941s

Chief Petty Officer
Joined
Oct 1, 2007
Messages
540
Re: tattle tale

Yea, it's not going to be shooting out hard enough to cut steel. The water pump impellar on those are for volume, not pressure. Should be a nice steady stream when it's going and when you feel it, it should a slight pressure at idle, full speed will have pressure about equal to a water hose turned half way on.
 

shimano

Petty Officer 2nd Class
Joined
Jul 26, 2008
Messages
143
Re: tattle tale

Just rechecked mine.Seems ok I think I'm used to a stronger stream.Held my hand under the stream and the temp seemed to fluctuate from warm to hot back too cool,This must be the thermo working.Also at idle there seems to be a lot of water coming out of different places on the lower leg,If the thermostat is closed is there somewhere the pressure goes?(bypass?).
 

will941s

Chief Petty Officer
Joined
Oct 1, 2007
Messages
540
Re: tattle tale

Thats normal, water should be coming out of the prop, the hole on the side of the foot, and maybe some where the foot and the mid meet. As long as the powerhead never gets too hot to hold your hand on it your fine. Also, with the t-stat working correctly the pee stream should go from a full pee to a trickle, then full pee again...then so on and so on. Runs at 120 degrees.
 

shimano

Petty Officer 2nd Class
Joined
Jul 26, 2008
Messages
143
Re: tattle tale

Sounds exactly like what mine is doing,Although I'm running it in a barrel so I can't see what's happening under the water.I ran it at about 1500 rpm in neutral for a while and could always hold my hand on the cylinders.Next time out I'll bring my laser thermometer and make sure.I was just concerned because the old merc I had had a pretty steady 'strong stream.Thanks for the help!
 

will941s

Chief Petty Officer
Joined
Oct 1, 2007
Messages
540
Re: tattle tale

No problem. The older mercs did'nt have a t-stat and ran WAY cool. When I got my first 25hp (89' year model) I was freaked out by the pee stream. Did'nt take the boat out for a long time til I found out it was normal. Now I own that one and a 98' year model and I change the t-states every year....and forget about it. The metal on the motor is going to be hotter, due to the warm water, and well, it's black. The sun heats it up and it holds heat. So if you use the thermometer and it's warmer it's ok. Test the pee stream for a more accurate temp. Also, you may want to change the t-stat if you hav'nt done so, just to be on the safe side before the season really opens. Put some anti-sieze grease on the bolts to keep them from getting corroded and sticking in the block, and having to have them removed. If the t-stat hasnt been changed in awhile....Be extra extra careful removing the two bolts. Use some heat if you have to. Hopefully they will come out nice and clean the first time. Good luck and you have a great motor!
 
Top