temp guage for 25 rude?

[longdude17]

I have an old 25 rude a 73' model to be exact. Can I put a temp gauge on it so that I can watch the temp of the motor (just to be safe) I am steering the boat from the front so I cant look at the back of the motor to see if the water pump is pumping. this temp gauge will ease my worrying.

 

[petryshyn]

Re: temp guage for 25 rude?

You will be much further ahead installing a water pressure gauge. Once you detect overheat on a temp gauge, its probably too late....A pressure gauge will give early warning and also show degradation of your water pump, telling you its time to change it before failure....<br /><br />

 

[Neil]

Re: temp guage for 25 rude?

Schematic, your advice appears logical.<br /><br />How would yuo go about doing this. Is is a dealer job?<br /><br />I have a Evinrude 140 but I believe the water system operates at a low pressure. The tell tail pours rather than jets. Would it work on this type too.<br /><br />NG

 

[petryshyn]

Re: temp guage for 25 rude?

NGRIFF1<br />Its as easy as drilling and tapping in the appropriate area...<br />I think you can get away with at tee where your telltail hose connects to an elbowed fitting...<br />If your pressure appears low, maybe it is....here is a general guide on what to expect...<br /><br /> Click this

 

[Neil]

Re: temp guage for 25 rude?

Schematic<br /><br />You never fail to impress. Obvoius where the name comes from <br /><br />Seems a straight forward job.<br /><br />My engine is a v4 but not listed there but I guess it should be in the region of 10 PSI.<br /><br />Even with a new pump it still dribbles out, but this is at idle. I should check at WOT - if I ever get to that stage. You have seen my other post.<br /><br />Thanks<br /><br />NG

 

[lonewolf5347]

Re: temp guage for 25 rude?

what you can also do is to install a temp. sending unit that you attach some where on the head it will read surface temp.if you would like to get this sending unit e mail me .lonewolf5347@cs.com I have one on my 120hp engine works great

 

[lonewolf5347]

Re: temp guage for 25 rude?

what you can also do is to install a temp. sending unit that you attach some where on the head it will read surface temp.if you would like to get this sending unit e mail me .lonewolf5347@cs.com I have one on my 120hp engine works great

 

[longdude17]

Re: temp guage for 25 rude?

thanks you guys! But what I am looking for is a temp gauge that I dont have to drill into the block as schematic wants. I dont have a telltale pee hole, and I dont Know what the water pressure of this old motor should be. will a regular temp gauge from napa work? also what is the normal orerating temp for this motor

 

[Boatist]

Re: temp guage for 25 rude?

Longdude While both gauges are good, I also prefer a temp guage. I have 1975 15 HP Johnson and it has lots of hours on it. In about 1990 I did change the impeller and install the stainless steel cup model. I had the unit apart this summer when I changed it form a 15" to 20" shaft and the pump is good as new. The pressure guage will tell you if impeller is going bad. I guess that is not a big deal to me as never had one fail in any motor and been boating since 1965. The pressure guage will not tell you if the 150 degree thermostat is stuck shut and the motor is over heating or stuck open and running cold. My motor has had thermostat stuck open about 4 times and one time stuck closed. My motor these days is used as a kicker for trolling or slowing drift and for safety offshore should the main motor fail. I here people say there are ones you can attach to a head bolt but have yet to see one in a store or catalog or web site. I also hope someone knows of a source.

 

[MGuckin]

Re: temp guage for 25 rude?

I have both gages, temp & pressure. <br />Pressure gage acts as early warning system of insufficient water flow.<br />Bolt Mounted Temp Sensor

 

[Lark40]

Re: temp guage for 25 rude?

I'm not sure why you want to go through the hassle of adding gauges to a primitive, yet very reliable engine. To add a pressure or water temp gauge, you have to tap a thread into the thin metal of the water jacket. <br /><br />I have the same concerns you have. But, to check that water is pumping, I can just look back while turning the boat, or shift into neutral, turn it and look back. The engine should be spitting some spray through the upper exhaust hole.

 

[longdude17]

Re: temp guage for 25 rude?

well thanks again you guys for all the help. does napa sell the top mounted sensor? well lark40, I know that this old motor is pretty reliable, but If it were just me driving the motor then I wouldnt be doing this. My girlfriend also likes to fish so I let her take the boat some times, and she doesnt know how to tell if the pump is pumping(I tried to show her) or what to look for. this is why I am installing the gauges. so she can watch the temp of the motor and so that I dont have to hear her cry if something does happen. Also does the thermostat get stuck often in these types of motors? If so how do you know if the thermostat is stuck open?

 

[Lark40]

Re: temp guage for 25 rude?

If the thermostat was stuck open, you can tell by the water jacket being coolish to the touch, also by the lukewarm temp of the exhaust spray.<br /><br />But, I can understand your situation with your girlfriend not being an old mechanic, so it makes sense for you to get a gauge.

 

[petryshyn]

Re: temp guage for 25 rude?

longdude17<br />All sensors can be top mounted.....

 

[longdude17]

Re: temp guage for 25 rude?

thanks guys! but I have one more question about a thermostat. yesterday with my boat idleing I put my hand in the water spray comming out the back of the motor and it wasnt cold but it wasnt hot enough to burn my hand. It was about the temp of a mildly hot bath. is this the way it should feel, and do thermostats get stuck commonly on these motors? how often should I replace it.

 

[petryshyn]

Re: temp guage for 25 rude?

Sounds good. You should service(check) your thermostat once a year.(pending on operating conditions)

 

[Lark40]

Re: temp guage for 25 rude?

Yes, that is how it should feel.<br /><br />I've been playing with these engines since 1958....

 

[longdude17]

Re: temp guage for 25 rude?

Thanks again guys! yall have been lots of help.<br />I was just wondering if any of you knew the size and pitch of the appropriate prop for this motor. I have this motor mounted on a 14 foot bateau that wheighs probably no more than 150 pounds, and it goes fast right now. How do you know if your prop is to small? How do you know if your over revving the motor while running. I dont have a tach. Can I put one? thanks again

 

[Lark40]

Re: temp guage for 25 rude?

Regarding your tachometer question, yes - they are available.<br /><br />I have a TinyTach (www.tinytach.com)for my 1960 Lark 40 and am very pleased with it. <br /><br />You will need to call them to make sure you get the right model (magneto two cylinder two stroke with two sets of points).

 

[longdude17]

Re: temp guage for 25 rude?

thanks for the info on tachs. but what is the appropriate size prop for this motor pushing this ammount of wheight.(300 ponds total=boat+me+gas)I have two different props. I have the factory prop that came off of this motor and I have the factory prop that came off of 69' johnson 25 is there any difference? i use the johnson prop as a spare prop.what I am asking is will I be over revving the motor with these props since im pushing so little weight.