This is an '89 Johnson 70 hp VRO. It usually starts and runs well. Not this summer though.
Recently on the water the alarm went off at high speed (constant alarm, high heat). I shut down immediately, restarted and was able to run for quite some time at low speed back to the dock, with no problem. The tell-tale seemed ok at all times, but I can't say for sure I looked right away when I shut it down.
My mechanic put a new t-stat in and the same thing happened. I called him on the water and he suggested taking it out to get back to the dock. I did that and it ran fine even at high speeds. The tell-tale was ok at all times without a t-stat. After doing some research it sounds like that is not a long-term solution.
I took both old and new t-stats and put them in a pot of water. They both seemed to open at roughly the same temp (not exactly sure what that was though, under 180 I think).
So this morning I put muffs on, the old t-stat in and started it. It idled fine. I ran it up to 4500 or so (in neutral) and after a minute or two the stream started spitting and slowing. I shut down immediately, before the alarm could go off. I put the new t-stat in and exactly the same thing happened.
It doesn't sound like there is much in the way between the water pump and t-stat on this motor (but I'm not sure). Would replacing the water pump and impeller likely solve this? I know I haven't replaced it in the 6 or so years I've had it, and the previous owner didn't seem like the type to do much preventative maintenance. I'd sure like to get on the water before summer is over, and not worry about alarms going off.
Thank you in advance for any advice!. I really tried to figure out things from this forum and others, but I didn't find anything that fit my circumstances.
Recently on the water the alarm went off at high speed (constant alarm, high heat). I shut down immediately, restarted and was able to run for quite some time at low speed back to the dock, with no problem. The tell-tale seemed ok at all times, but I can't say for sure I looked right away when I shut it down.
My mechanic put a new t-stat in and the same thing happened. I called him on the water and he suggested taking it out to get back to the dock. I did that and it ran fine even at high speeds. The tell-tale was ok at all times without a t-stat. After doing some research it sounds like that is not a long-term solution.
I took both old and new t-stats and put them in a pot of water. They both seemed to open at roughly the same temp (not exactly sure what that was though, under 180 I think).
So this morning I put muffs on, the old t-stat in and started it. It idled fine. I ran it up to 4500 or so (in neutral) and after a minute or two the stream started spitting and slowing. I shut down immediately, before the alarm could go off. I put the new t-stat in and exactly the same thing happened.
It doesn't sound like there is much in the way between the water pump and t-stat on this motor (but I'm not sure). Would replacing the water pump and impeller likely solve this? I know I haven't replaced it in the 6 or so years I've had it, and the previous owner didn't seem like the type to do much preventative maintenance. I'd sure like to get on the water before summer is over, and not worry about alarms going off.
Thank you in advance for any advice!. I really tried to figure out things from this forum and others, but I didn't find anything that fit my circumstances.