Is this temperature normal?

[jiffyboat]

I have a 1996 Johnson 130Hp, and it seams to me that is running a little bit hot, one bank is reading 150 degrees and the other 165 degrees, is this normal. I just changed the T-stats and still the same problem, I also pulled the head to check for restrictions around the cylinders , but it was clean, the bank that is running at higher temperature has 100psi of compression and the other 120psi,..could this be the cause of difference in temperatures, I think that lower compression will develop lower temperature, I have had another johnsons and they run at lower temp , this one actually seams hot at tact..any suggestion,,thanks

 

[tashasdaddy]

Re: Is this temperature normal?

I would do a decarb on it. carbon on the inside hold heat.

 

[kenmyfam]

Re: Is this temperature normal?

A little high in my opinion. Decarb as suggested by TD.
Changed out the impeller lately ???

 

[Texasmark]

Re: Is this temperature normal?

People on the OMC forum don't like me to talk about Mercs, but I have a Merc not an OMC so either I lie or talk about comparisons between the two; but I have had OMC's for a very long time and sometimes I talk about them.

The stats in my current Merc associated engines open at 143F +/- 5 degr F (according to the book). Well, if it starts opening at 143 the water is going to get quite a bit hotter before it is fully opened. Therefore your numbers aren't that bad as far as I am concerned.

However, most engines of which I am aware nowadays have a pop-off valve that opens a hole about 4 times the area of the stat hole when the engine is over around 2500 rpm's or when the boat is going forward fast enough to generate enough pressure to unseat it.

When that happens, the stat is essentially out of the loop and any heat you built up at the slower speeds should dissipate and the engine should cool down somewhat. If not, then you might be concerned.

Since we are just now coming out of the winter and since ambient water temp has a huge impact on engine temp (with the pop-off open) you might take a second look.

My 2c,

Mark

 

[jiffyboat]

Re: Is this temperature normal?

I forgot to mention that the water pump impeller was changed also..and I will also try that decarb..I read in a thread that it should be done with one gallon of gas and a full can of seafoam..is that correct?

 

[jiffyboat]

Re: Is this temperature normal?

I also noticed that the water takes like 20-30 second before it star coming out of the pissing hole or of the exhaust, in the other 200hp that I had it was pissing right away, after starting

 

[kenmyfam]

Re: Is this temperature normal?

I also noticed that the water takes like 20-30 second before it star coming out of the pissing hole or of the exhaust, in the other 200hp that I had it was pissing right away, after starting

Are you certain there is no blockage anywhere. Have you given the motor a backflush ???

 

[bktheking]

Re: Is this temperature normal?

I also noticed that the water takes like 20-30 second before it star coming out of the pissing hole or of the exhaust, in the other 200hp that I had it was pissing right away, after starting

Maybe you have a restriction somewhere.

 

[jiffyboat]

Re: Is this temperature normal?

I pulled both t-stats and hooked the water hose by the t-stat hole and the water came out by the lower unit fine, even I pulled the lower unit and hooked the water direct into that pipe that goes into the water pump and you can hear the water like filling the block and air coming out of the pissing hole until it finally starts coming out

 

[jiffyboat]

Re: Is this temperature normal?

other thing that I noticed is that when the motor is running some water comes out of the lower unit , by where the water pump is located, it could be a leak in the water pump housing , no getting all the water up to the top of the motor ..has some body had this problem before

 

[kenmyfam]

Re: Is this temperature normal?

other thing that I noticed is that when the motor is running some water comes out of the lower unit , by where the water pump is located, it could be a leak in the water pump housing , no getting all the water up to the top of the motor ..has some body had this problem before

Did all the "O" rings etc go back in the correct place ????

 

[jiffyboat]

Re: Is this temperature normal?

yes all the O rings all there , but old , with the impeller didn't got any new ..can this be the problem? hm, I think I will try new orings, and see what happen

 

[kenmyfam]

Re: Is this temperature normal?

yes all the O rings all there , but old , with the impeller didn't got any new ..can this be the problem? hm, I think I will try new orings, and see what happen

When on the muffs water comes out all over the place and that is entirely normal. My concern is that there is enough getting up to the powerhead. Your temp numbers are not horrific. The 150 side is O.K. it is the 165 degree side that is on the high side. You are not going to "fry" anything at this temp but if it gets worse you could. Are you checking this on the muffs or on the water ?

 

[tashasdaddy]

Re: Is this temperature normal?

it takes a few seconds for that block to fill with water, the tale tell is the last place to fill.

 

[Texasmark]

Re: Is this temperature normal?

My overtemp alarm sensor is set to 190F if that gives you any indication as to what one OEM thinks is excessive temperature. I don't know where the OMC OT alarm is set, but probably real close to that number.

Mark

 

[ezeke]

Re: Is this temperature normal?

My overtemp alarm sensor is set to 190F if that gives you any indication as to what one OEM thinks is excessive temperature. I don't know where the OMC OT alarm is set, but probably real close to that number.
Mark

The temperature switch with a tan wire closes at 203? +/- 6? F. The temperature switch with a tan w/black stripe wire closes at 212? +/- 6? F.

The thermostats are 143? F. thermostats. According to the factory manual, temperature of the 130HP cylinder heads should not exceed 150? F. at 900 RPM and temperature should not exceed 120? F at 5000 RPM.

 

[jiffyboat]

Re: Is this temperature normal?

Ok I went back to the motor today and took the lower unit out , the WP housing didn't looks very well, so I desired to change the water pump and got a brand new OMC kit, now the reading were down a little bid , right bank is reading 140 degrees and the left 150 , but still according to the upper explanation is some how high, no terrible , but hight, I will definitely go down to 120- 130 degrees, I will try tomorrow that decarb...I will let you guys know tomorrow, and thanks for all your advices