merc 1250 1969 location of temp sensor

[twkjr 1250]

location of temp sensor

 

[OldMercsRule]

Re: merc 1250 1969 location of temp sensor

location of temp sensor

No such thing. Simple water pump and tell tale, (as long as the tell tale is not blocked which compressed air cures). Always on. If no tell tale fix water pump. Simple as that. JR

 

[twkjr 1250]

Re: merc 1250 1969 location of temp sensor

thanks for that info , now is there any way to hook up some kind of warning device so i dont ruin the engine if pump fails

 

[Droll]

Re: merc 1250 1969 location of temp sensor

You could invest in a water pressure gauge, they got some here on Iboats

Not sure exactly what range you will need, but you might need a 0 - 15PSI gauge.

This hocks up to the tell tail with a "T" connector and will give you what you need....( PSI drops = are some problems... )


Arne Kjetil

 

[OldMercsRule]

Re: merc 1250 1969 location of temp sensor

thanks for that info , now is there any way to hook up some kind of warning device so i dont ruin the engine if pump fails

You can do whatever ya want, and as Droll says water pressure is the only reasonable solution if you must have a guage, (a low presure one). That said: I have run outboards fer many many years.

I have trained my three kids, (all now adults), to run my outboards and learn good habbits as well and we have never burned up a powerhead due to heat. My larger ones are 30 plus years old and some are virgins that still run great.

The beauty of an old engine like yer 1250 is simplicity. It has two weaknesses: fuel system and cooling system. When ya run the engine the very first thing you look at is the tell tale after ya fire her up and ya train yerself to look at it every few minutes therafter as a habit that after a bit ya never even notice as it becomes second nature when she is underway.

You will have to do the same thing with a pressure guage that will cost ya time and money to instal, and not be nearly as obvious, and be another thing to maintain.

My overpriced $02. JR

 

[Moody Blue]

Re: merc 1250 1969 location of temp sensor

Agree with the pressure gauge. Definitely go with the 0-15 range. With a new impeller at idle, it will only register 3-5psi and at WOT maybe 10-12psi. You will hardly see the needle move with the 0-30 gauge whereas you will get almost full range on the 0-15.

On many motors there is also a port where you can install a temp sensor and connect to a gauge. Many don't believe in the value/effectiveness of a temp gauge but I have both pressure and temp gauges. Call me paranoid

 

[daveswaves]

Re: merc 1250 1969 location of temp sensor

Water pressure gauge is far better than temp sensor, by the time the temp sensor starts to climb its almost too late.

 

[OldMercsRule]

Re: merc 1250 1969 location of temp sensor

If a duck wants a rudder n' has the money n' time n' inclination to install and maintain said rudder: go for it.

There is nothin' "paranoid" in wantin' to moniter yer engine's water pressure n' temp at various RPMs. I don't have any problem with that at all, and I also think it is a good idea to get in a habbit of doing it whether lookin' at a guage on yer dash or turnin' yer head n' lookin' at yer engine.

I own and run a number of old inlines, (I'm addicted to 'em ). I watch the tell tale all the time for both volume and presure, and only one of my boats has a line of sight issue where I would be tempted to install the pressure guage you are talking about. I have to stand up from time to time when behind the wheel.

I jus' bought another boat where this maybe an issue due to the size and type of vessel so I may do jus' what you did as well.

IMHO, it is a good idea to be aware of yer surroundings, (fore and aft when underway), which bein' in a habbit of periiodically checking the tell tale forces ya to do, (especially if the powerhead n' tell tale is in yer line of sight). That all said: boating is about pleasure, and we all know they, (boats), are holes in the water that money and time is poured into.

So if it floats someone's boat ta install a bunch of fancy guages on a simple old 40 year young engine: SO BE IT. JR

 

[Droll]

Re: merc 1250 1969 location of temp sensor

install a bunch of fancy guages on a simple old 40 year young engine: SO BE IT. JR

Well some gauges are needed, or at least a tach....don't have any water pressure gauge but I got a temp gauge.....but it barely moves ( does work but... runs to cold ) ..
Had it for my old Johnson 90.. currently running a big black Merc ( 90hp, ported to 140 ( 72 140hp spec )).

I think Mercury had a service bulletin on some of those old L6 engines.... a relocation of the tell tail outlet from the block, it was moved from the lower part of the exhaust cover to the top of the cylinder block.
Less chance for any steam locks in the cooling system ....later model had it between cylinder 3 and 4 ( on the cylinder head cover ), last models had it above #1 .


Arne Kjetil

 

[OldMercsRule]

Re: merc 1250 1969 location of temp sensor

Well some gauges are needed, or at least a tach....


TOTAL AGREEMENT. I always cornsider a tach as basic REQUIRED equipment fer any old inline ya want to keep alive fer more then a few minutes.

don't have any water pressure gauge but I got a temp gauge.....but it barely moves ( does work but... runs to cold ) ..

Hmmmmmmm.... if I hook one up to the 1500, (if I can't see the tell tale once I hang it on the boat, [still unknown]), it will be a pressure guage. I don't know what good a temp guage would do since water temp here in God's country varies soooooooo much dependin' on the time of year or body of water yer hot roddin' around on et al.

Had it for my old Johnson 90.. currently running a big black Merc ( 90hp, ported to 140 ( 72 140hp spec )).

If I had one on the boat and I had a place to install a sensor on the engine block I guess I would be tempted as well. Still dunno if I would do it as water pressure seems a more reliable n' positive thing ta know, if the line of sight is blocked or difficult fer whatever reason ta see from the helm. (like poor eyesight fer us old farts ).

I think Mercury had a service bulletin on some of those old L6 engines.... a relocation of the tell tail outlet from the block, it was moved from the lower part of the exhaust cover to the top of the cylinder block.

Ya know: NOW YOU HAVE ME ATTENTION. I am gettin' me 1977 1500 ready fer the water n' I had ta replace the plastic 1/8 x 5/16 (that was stripped and loose), elbow with a brass one from the middle of the water jacket (head cover). I do rememder that me 1976 1500 was plumbed from a place higher on the block and that place that I put the brass elbow was blocked off. Where do I hook up the tell tale, I didn't see a fitting higher on the block? I may need to start a new thread to find out if ya choose not to reply. I wasn't aware that was a critical issue, but it very well maybe!!!!


Less chance for any steam locks in the cooling system ....later model had it between cylinder 3 and 4 ( on the cylinder head cover ), last models had it above #1 .

If there isn't a place higher on the cylinder head cover do I drill n' tap one?? I hate to fix things that aren't broke. Seems the 1977 1500 should have what the 1976 1500 had (and that didn't look like it was drilled and taped), if memory serves me. JR


Arne Kjetil

...