Hi all, new to here, looks like a very helpful forum..
The carbed 175 (06 block) is coupled with a sport-jet system, but has been modified to a closed loop cooling system, which isn't working. It was changed due to contaminants in the operating environment - weed, shallows, tree roots, swamp etc and low speeds , keeping the temp up. With the jet unit originally supplying the cooling water, running at low speed, just above idle, heat alarm buzzer was going off.
It is only running a short time without overheating, so I thought I would run the config and some symptoms past you.
1 On the port side, base of block, is the cold inlet - with corresponding outlet on the starboard side.The connections are either in the base of he block, or sport jet housing - not sure. Are there a standard external fittings here?
2 When running, the connection hose , between the top of the heads doesnt recieve any cooling water. (when disconnected, just steam / smoke comes out) I am assuming thermostats have been removed - as I can connect a hose to one side and get flow out of the other, but not from the water comming from the base connections flowing under normal use.
3 Temp gauge gets to about 150, before it gets switched off.
4 The main flow is not much more than a light trickle - even though the pump used runs at 80lts / min
I do not know much about the poppet valve, it's placement ( star side lower - somewhere - I believe) could this be an issue?
I feel a good place to start is to disconnect the closed loop, use a hose in the inlet side, and see what effect this has - if any, but I just don't want to overheat accidentally.
My feeling is that there was a giant air pocket in the top of the heads, but as I am not sure of the waterjacket flow, or even if the inlet / outlets are connected where they should be, I am not sure if I am going to do damage.
The closed cooling circuit was supposadely done professionally, by a professional service agent.
I have no diagrams of waterjacket flow, and cannot find much documentation or illustrations concerning this problem.
Any thoughts or ideas are appreciated.
The carbed 175 (06 block) is coupled with a sport-jet system, but has been modified to a closed loop cooling system, which isn't working. It was changed due to contaminants in the operating environment - weed, shallows, tree roots, swamp etc and low speeds , keeping the temp up. With the jet unit originally supplying the cooling water, running at low speed, just above idle, heat alarm buzzer was going off.
It is only running a short time without overheating, so I thought I would run the config and some symptoms past you.
1 On the port side, base of block, is the cold inlet - with corresponding outlet on the starboard side.The connections are either in the base of he block, or sport jet housing - not sure. Are there a standard external fittings here?
2 When running, the connection hose , between the top of the heads doesnt recieve any cooling water. (when disconnected, just steam / smoke comes out) I am assuming thermostats have been removed - as I can connect a hose to one side and get flow out of the other, but not from the water comming from the base connections flowing under normal use.
3 Temp gauge gets to about 150, before it gets switched off.
4 The main flow is not much more than a light trickle - even though the pump used runs at 80lts / min
I do not know much about the poppet valve, it's placement ( star side lower - somewhere - I believe) could this be an issue?
I feel a good place to start is to disconnect the closed loop, use a hose in the inlet side, and see what effect this has - if any, but I just don't want to overheat accidentally.
My feeling is that there was a giant air pocket in the top of the heads, but as I am not sure of the waterjacket flow, or even if the inlet / outlets are connected where they should be, I am not sure if I am going to do damage.
The closed cooling circuit was supposadely done professionally, by a professional service agent.
I have no diagrams of waterjacket flow, and cannot find much documentation or illustrations concerning this problem.
Any thoughts or ideas are appreciated.
Last edited: