Cooling Adjustment

[imayachtsman]

I just purchased my first jet boat and am clueless about a few things. I'm going through the boat to check things out before I put it in the water. near the transom there is a ball valve with a hose connector. It looks like it is conected to the back of the Berkley pump. I know this hose attachment is for running the boat on the trailer but I don't know if the ball valve is to djust the water flow to the engine.

[El Prosecutor]

Most guys will tell you not to run it on the trailer at all, but there are mixed opinions. I think all will agree that if you do run it on the trailer you better be sure to have water running through it.
The ball valve is for adjusting the volume of engine cooling water that flows from the jet to the engine. Opinions vary, but in general you want it opened about 1/4 - 1/2 turn, enough to keep the water temp at about 180* at idle, and about *160 at cruising. You can search the forums and get lots of informed opinions on the specifics. Things are also done differently depending on whether you are running headers or a log exhaust.
Welcome and congrats on your new jet!!

[slingingsmoke]

can u post a pic????

[Mighty Thor]

Most jet owners will tell you not to run the jet on the trailer. Some will tell you you can if you provide water to the pump and to the engine and there will be a host of different opinions on how this should be done. But everyone will tell you not to run the jet on that one hose fitting alone. While it may provide water to the engine, it will not put enough water into the jet to keep damage from happening. The jet itself is a pump designed to push water into that valve, Flow will not go the other way very well. Personally, I only run the motor when the pump is in the water. Having bought enough pump parts, I don't want to have to do it again.

[El Prosecutor]

Most jet owners will tell you not to run the jet on the trailer. Some will tell you you can if you provide water to the pump and to the engine and there will be a host of different opinions on how this should be done. But everyone will tell you not to run the jet on that one hose fitting alone. While it may provide water to the engine, it will not put enough water into the jet to keep damage from happening. The jet itself is a pump designed to push water into that valve, Flow will not go the other way very well. Personally, I only run the motor when the pump is in the water. Having bought enough pump parts, I don't want to have to do it again.
You will get many opinions, but this is the voice of wisdom. I am with Thor; better safe than sorry.