Montrone, you live in California eh,so why worry about the thermostat when the lakes down there warm like soup most of the time.I haven't used a thermostat up here in British Columbia where only Lake Osooyos matches the temperate waters of california's lakes.Less parts to go wrong ,less worry.Just use a gate valve at the incoming water from the bowl.You can purchase an inexpensive waterpressure gauge at your hardware store,that you install temporarily between the gate and the engine ,and dial in the pressure around 15 pounds maximum.Then make note at the valve position for the approx setting.You may want to change the setting depending on water [lake or river]temperature for the morning or afternoon.It would only take a slight movement to make a different reading.Remember ,the temp will rise at Idle but don't worry about it.Your engine will never run as hot as in a car because of the fresh water volume going through the engine.
A couple more things to check. If you are idling slow you might try a couple hundred more rpm at idle.
The male adaptor out of the pump with the original PackJets has a built in restrictor. If this is the case try a regular fitting.
I don't like to have engine temp go up too high during idle. When you take off with a hot engine you have more tendency to detonate. This is a problem if you are on the edge. Km
Originally posted by spectras only:
Montrone, you live in California eh,so why worry about the thermostat when the lakes down there warm like soup most of the time.I haven't used a thermostat up here in British Columbia where only Lake Osooyos matches the temperate waters of california's lakes.Less parts to go wrong ,less worry.Just use a gate valve at the incoming water from the bowl.You can purchase an inexpensive waterpressure gauge at your hardware store,that you install temporarily between the gate and the engine ,and dial in the pressure around 15 pounds maximum.Then make note at the valve position for the approx setting.You may want to change the setting depending on water [lake or river]temperature for the morning or afternoon.It would only take a slight movement to make a different reading.Remember ,the temp will rise at Idle but don't worry about it.Your engine will never run as hot as in a car because of the fresh water volume going through the engine.
still new at this sport, and I do appreciate the heads up.
it's when I called (Summit Racing) for parts on my truck they just reconmend to use this on my boat engine, but I should take in consideration they might not know nothing about boat engines.
The temp changes you are experiencing, vary too much. The colder to hot water changes could cause the valves in your head to become brittle and snap causing heavy engine damage. Also, don't run a thermostat without a bypass system or you risk blowing head gaskets from too much pressure.
Does anyone know what kind of pressure and flow (in gallons per minute) I should be getting through the water connector from the jet? Thanks in advance.
Just an update: I brought the boat in to Greg at GS Marine and he got the motor dialed in. We fired it up while hooked up to the garden hose. As he expected, the temp didn't get past 110 or 120F. This proved that I don't have blockage in the water passages in the engine.
I dropped the boat in the water the following week. After letting it run to get up to temperature, I get the following temps: 130F crusing and 180 idling. I know that this is acceptable for the motor's temp range but Greg thinks that my pump is losing efficiency. He said that I should only get 110 to 120 since I don't have a thermostat or a gate valve.
The question: Is the wear ring the part of the pump which deteriorates causing the jet pump to lose efficiency? I didn't want to have to go through a complete pump rebuild as my impeller is practically brand new and that my bearings don't seem to be shot. If the wear ring is not the culprit, which part of the pump would be? The reason I wanted to take this approach first is that it doesn't take a lot of effort to get to the impeller as opposed to a total pump rebuild.
Thanks in advance.
Inciong, Greg is right,120 degree temp without thermostat, water supply hose valve fully open .The only thing could be a problem if the impeller was machined to go forward on the pumpshaft causing a decrease in water flow from the impeller[meaning a very small gap between the pump and suction housing.This wouldn't be the case with the shoulder type wear rings and a new impeller,but I've seen pumps with the old stainless rings with people modifying the impellers to their own liking.I'm afraid you may have to pull the bowl off ,and pull the impeller off to check the clearence between the impeller and suction housing.Didn't Greg offered to check that out?Another thing could cause your problem ,if your wear ring and impeller has too much clearence [shouldn't be the case if your builder is a reputable one] and the water pressure blows back to the suction housing.But then you'll notice a huge loss in performance.
[This message has been edited by spectras only (edited July 02, 2001).]
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