View Full Version : water pressure gauge ??? HELP
I have a Yami 115 hp main motor and put a water pressure gauge on it when i was experimenting with engine height and props.She normally runs at no lower than 1100 psi fully trimed up,but usually at between 12-15.Yesterday i noticed it was at 8-9 psi,,,,even when fully trimmed down.I put her in neutral and revved the engine and it still wont go over 10 psi.Should i change the impeller or is there anything else i should check before sending it off to the mechanic to look at it.Thanks alot,Kdog
perchjerker
06-16-2002, 12:40 PM
K, Im sure your mistaken about it being 1100 psi. Maybe you mean 100?
How long has it been since you did maintinance on your water pump? Maybe its just getting tired.
KDog, I'd replace the impeller. Did you notice it slowly dropping over the course of the season? Were you pulling 12-15psi last season and you have just taken the boat out this season for the first time? If so, vanes may have taken a set and have lost their efficiency. If you were pulling 12-15psi and SUDDENLY dropped to 8-9psi you may have lose a couple of vanes on the impeller, or it's also possible that you sucked up some schmutz (mud and crud) and it's limiting the flow. Personally I'd replace the impeller first, it should be done every two years as regular maintainence. I think this will fix the problem.
Best Regards,
FJH
I'll bet he meant 10-11 psi. You could have been getting air when running at the higher setting. Your pump housing may have warped, or the impeller worn. It won't make as good of vac. if things don't mate properly. I'll bet if you change them both, you'll have at least as high of pressure as before.
FJH,
I usually fish at least twice a week,sometimes more and it usually is between 12-15 psi depending on trim level.Its been a sudden drop to 8-9 psi.So it may be something sucked up into the water intake or a impellar problem or possible water pump.Thanks guys im just looking for solutions and what may be the problem before takeing her in,,,if its a quik fix i can handle that,dont want to bring her in if i dont have to.Thanks fellas,Kdog
I've thought about adding psi guages to my 115's. Is this an off the shelf mod or something that you designed/configured? Which guage did you use and where did you install it?
Thanks,
MDT
Scott
06-17-2002, 04:40 PM
There should be a pipe tap on your motor for the water to flow from the block to a fitting to the tube to the gauge. It's a simple process. You can get them from Cabelas or any dealer. If you look through places like grainger etc, you can get a better gauge for less money. You'll have to come up with the fittings and tube, but it's fairly simple. You need to rig a tee at the back of the gauge to drain the water at the gauge when you get close to winter. Water in the bourdon tube will freeze, straighten the bourdon tube, and destroy the accuracy and zero of the gauge.
Just wondering how hard it is to change the impeller. I think mine is starting to go on my 200 efi. Any help would be great. It has never been changed,the Merc. is a 99 model Thank You Bob
It's not that tough. Two people will make the job much easier. I changed my 175 efi this spring and it took me about 1.5 hours (I'd never done one before). If I had to do it again I think it would be 45 minutes or less. If you don't have a manual for your 200 efi, get one, it makes the job like following a cookbook.
Best Regards,
FJH
FJH, thanks for the reply. Let me know if there are little secrets to changing it. Bob