no water at idle

[supersoaker509]

At idle 800rpm I lose water to the motor.
I have two water dumps and about 30sec. after I come off plane I lose water coming out of the dumps and motor starts to over heat. Pick R's up to 1500 all good.
All lines are clear,oil cooler clear.:confused:
Plumbing same as last year, new last year.:confused:

[OverKill]

Do You have Enter and Exit Valves?? If so set everything at Half.

[79centurion]

Something stuck in the jet maybe restricting the flow, or maybe you have it restricted too much if you run a restrictor.
Dan

[supersoaker509]

I'm running one ball valve at the pump only.
I check the valve is working fine.
I also ran a screwdriver thru the pump side to make sure it was clear to the impeller.
How much psi. should be in that line off the pump?

[OverKill]

I think it's 50 in the bowl. Not sure at the line. IMO you need an entrance and an exit valve. It's the only way your gonna know what your motor wants as far as water cooling temp. Also if your running injected headers it's the only way your gonna find the perfect balance. Also are all of your gaskets good?? Make sure you have a perfect seal and water isn't leaving the motor before the dump. Take a peak and let us know

[supersoaker509]

I'm running water jacketed Bassetts with
Reduced Water Distribution

[supersoaker509]

Running this same set up last year the water temp stayed 140 to 160 all the time at 1/2 valve oil temp 210 to 230.:D

[OverKill]

Proecess of elimination LOL. Have you checked the ball valve it's self, How old is the valve? I personaly like to run virtacle gate valves myself. Just my 3 cents.

[supersoaker509]

I'm sorry....... there are no leaks, bowl and all fitting are in the boat freeze plugs, head gaskets,intake no leaks and no water in oil so no leaks there:D

[supersoaker509]

Proecess of elimination LOL. Have you checked the ball valve it's self, How old is the valve? I personaly like to run virtacle gate valves myself. Just my 3 cents.
I took it off today and it still looks new 1yr old, it's a S.S valve.

[OverKill]

No Im sorry. I wish my head would straighten out and have this figured out for ya. Let me go through some of my old notes and see what I come up with. In the mean time think about putting an exit valve on. Just so you can close it off from running to much water through the exhaust and put more water to the motor. Does that make any sense??
OverKill

[jbone]

Proecess of elimination LOL. Have you checked the ball valve it's self, How old is the valve? I personaly like to run virtacle gate valves myself. Just my 3 cents.
I agree... check the valve assembly. Actually remove it from the line and inspect it. Maybe a restriction there. If you are able to cool the engine by revving the motor to 1500 rpm, it might just a little restriction.
I know with my valve, just a 1/4 turn makes a big difference at idle.
J

[jbone]

Sorry, missed the part where you said you took it off. I'd check all the lines to the front inlets. A small piece of lake debrit could be stuck somewhere.
I do I dare say Zebra Mussels growing in there:idea:
J

[OverKill]

I think he might have camel tow blockage LMAO :)

[jbone]

I think he might have camel tow blockage LMAO :)
That would be a fairly large blockage:D

[supersoaker509]

I think he might have camel tow blockage LMAO :)
I just took all lines and fittings off and all is clear:confused: , no camel tow, :D
I will install a gauge to see what psi I have at pump line in, block

[Squirtcha?]

IMO you need an entrance and an exit valve. It's the only way your gonna know what your motor wants as far as water cooling temp.
I would have to disagree with this statement James. No exit valve needed. I ran for years without one. When redoing my plumbing I cut one in for grins and have never touched it (run wide open all the time). IMO too much time and money is spent trying to get a jetboat motor to run at 190 degrees. It's just not necessary. In fact even when you see 190 degrees on your temp gauge with an open loop system (probably 99% of jets are open loop) it's not really 190 degrees per se like a car motor with a closed loop (radiator) system.
It does sound like you've got some kind of blockage somewhere. Are you able to take your water lines loose while at the lake?
Just like troubleshooting an electrical problem. Make sure the pump is primed and disconnect the line from the pump to the valve and fire the motor for a couple seconds and see if you have water at that point. Provided you do, reconnect and take the next junction loose (after the valve) then the oil cooler and repeat etc. You won't need to run it for more than a couple seconds to check each junction/section. Yeah it'll dump a little water in the bilge but not a big deal for a couple seconds of run time for each section.

[bp]

Running this same set up last year the water temp stayed 140 to 160 all the time at 1/2 valve oil temp 210 to 230.:D
in my boat, pump pressure at idle (around 1100) is 18psi. at 4000, about 140psi. i run a regulator set so that pressure to engine is around 10psi, no valve.
open your valve until you get some water flow at idle... if you cannot get any water flowing through the engine at idle, you may have a pump issue.

[sdpm]

Did you happen to install a new Impeller in the off season? If so let me know and I will explain in detail. If not, take a real close look at the area on the impeller that rides where the wear ring is. If it has been ran dry a few times this area can get damaged and will wear right through the shoulder on the impeller and at low rpm you will not have much pump pressure. Another thing that will cause this is if the thrust brg is bad, the Impeller will creep forward and shut the water off to port, but then under a load it should get even worse (hot ) that is. Just a few things to look at. Good luck.