Water pressure ?

[KYHunter]

1978 Johnson 115 ETL, I have my water pressure gauge hooked up and working. Its a 30 psi., I have it hooked into tell-tale line , tell tale blocked off. I get 2-3 lbs. at idle and 11-13 lbs. at WOT (5100 rpms.), is this in the ball park for my motor ? I am trying to get a 17 pitch prop to bring my rpms up.<br /> Thanks,<br /> KYHunter

 

[Dhadley]

Re: Water pressure ?

Thats a little low on top especially if the overboard line is plugged.<br /><br />Remember -- going to a smaller pitch prop to increase rpm is the last thing to try.

 

[KYHunter]

Re: Water pressure ?

Dhadley, Thanks for the reply. When you say on top do you mean WOT? I just put a new water pump and pressure gauge on this motor.<br /> I hooked the pressure gauge in the tell-tale line that is tapped in exhaust cover lower starboard side , in the little square. <br />What should the pressure be? <br /> Before I hooked up gauge water shot 3 ft. out of tell tale. <br /> Do you think it could be the gauge or the way I routed the hose ? I ran the hose as the instructions said. <br /> Also need some advice on getting my rpms up. I've read several of your posts on boat set up. I think the motor is mounted right according to the other posts I've read. <br /> Please let me know what info. is needed to decide what to do next.<br /> Thanks,<br /> KYHunter

 

[DJ]

Re: Water pressure ?

KYHunter,<br /><br />I do not know what prop you have now, but, as a general rule, one inch in pitch is good for about 200 RPM's. Up or down.

 

[Dhadley]

Re: Water pressure ?

Yes, wot. You have it hosed right. But is the overboard line plugged completely?

 

[KYHunter]

Re: Water pressure ?

Yes, I have checked it while running no leaks. What I did was put gasket sealant on a stainless screw and then a clamp . It may be my gauge reading ability , its kind of hard to get exact numbers the way the scale on gauge is. I went out and looked at gauge and its definately reading below 15 psi. One thing I forgot to mention . When I start motor it takes several seconds for the gauge to show anything. Could there be air in the line? Or is this not a normal problem?

 

[KYHunter]

Re: Water pressure ?

bump

 

[rodbolt]

Re: Water pressure ?

unplug the tell tale. its not designed to be plugged. the tell tale should have a restrictor in it. if its missing replace it. have you checked the t-stats and the pressure control valves,grommets and springs ?

 

[Goodoleboy]

Re: Water pressure ?

If it were my motor. I would try it out on the lake, If it runs cool enough that the overheat alarm dosent sound off then I would call it good.<br /><br />I would think all engines will have a slightly diffrent water pressure reading. Depending how much lime and calasum build up their is in each engine. The more it has built up the higher the pressure it will build.<br /><br />I would just use the pressure reading you have now as a reference point for future readings.<br /><br />Like I said IF it were mine thats how I would approach it. As I have said in another post the water pressure gage is now your teltale. Its a visual check to show that your water pump is indeed pumping water. Thats all your overboard telltale ever did.<br /><br />But its not mine its yours, so its up to you ofcourse as to what you think is best.<br /><br />Good Luck!

 

[KYHunter]

Re: Water pressure ?

I have run it at the lake about 3-4 hours of run time no problems . The reason I unhooked the tell-tale was because of advice given here. The motor runs great no signs of overheating . I was just wondering what the pressure should be. There was a restrictor in the line but gauge wouldn't work until I plugged tell-tale.<br /> Thanks ,<br /> KYHunter