| I have the same question regarding my 30 Hp Johnson
Here is the background:
The motor is installed on a 13' Boston Whaler which is operated in a shallow
salt water bay. There is often eel grass floating on the surface which gets
wrapped around the lower unit. If I tilt the engine higher, the eel grass gets
caught below the anti-cavitation plate and causes cavitation (manifested by
excessive RPM and loss of power). If I tilt the engine lower, the eel grass
gets caught higher on the lower unit and blocks the cooling water intakes.
The result is that the overheating alarm sounds and I have to shut the engine
off for >15 minutes to cool down.
Of course, the best solution to this problem is not to get eel grass caught
in the engine, and although I try to avoid it as much as possible, it does
happen from time to time. So I need some kind of early warning mechanism to
tell me that there is a problem before overheating occurs (I could simply
watch the stream of cooling water which is pumped out of the engine, but
that requires constant turning around from my position at the steering
wheel)
What I would like to do is to run the engine in the lower position to avoid
the cavitation problems and install a temperature guage so that I can tell when
the cooling water intakes are blocked (by the way, this is a pretty rare event
compared to the cavitation when the engine is in the higher position). I have
seen guages in catalogues which describe an 'NPT' sensor (with different
thread sizes), but I'm not sure where on the engine I could attach this.
Any help with this (including other methods I haven't considered) would
be greatly appreciated.
--Bruce
|
| RE: .1
Bruce,
I'd start by calling the service dept. at Gauch Bros. in
Shrewsbury. They should be able to give you all of the info you
need, whether you want to buy from them or not. You didn't mention
the age of the motor, if it's so old that they can't help you then
you'll just have to get in touch with Rick Wilson.
(You could have just stopped me in the hall!)
B.C.
|