bull12001
Cadet
- Joined
- May 9, 2013
- Messages
- 24
Hi all! New to this forum and have found a lot of good information on here thus far.
First, a little history. I have a 1986 Stingray SVC 195 SS that was my grandpa's when I was a kid. He had some engine trouble and had to replace the stock engine with a new engine. It only had approx. 5 hrs run time on it when it was parked where it stayed under multiple covers for 20+ yrs. The boat itself is in good shape except a few cosmetic touch ups that are needed. I'm currently getting it ready in hopes for a second debut on Memorial Day weekend. I have everything rebuilt on the engine and am just checking a few things.
I just ran the motor for approx. 15 min on the hose to check temperatures. I'm pretty gun shy with the 470 because I had a previous boat overheat and cause god knows what problems. The temperature gauge doesn't move a whole lot from cold peg and stayed just below 120 F. Took a few temp readings with an IR thermometer and found 130 F give or take at the sender unit. The water discharge out the back stays a little colder than luke warm. I get 1280 ohms of resistance on sender unit at outside temp and tested 366 ohms when it was reading 130 F on the thermometer. Before anyone says it, yes the wire was disconnected during these tests. The gauge tests out fine (pegs hot when grounded at sender). The coolant hose into the heat exchanger stayed around 135 F and the coolant hose out of the heat exchanger stayed around 100 F. Unpainted portion of manifold reads around 210 F. Is that too hot for that part? I have had to add oil a couple of times. The manual says it is going to use oil more during the break-in period which it is still technically in. I do not find oil in the coolant (stays bright and green) and oil doesn't become brown or milky.
Unfortunately, I have no SN for the motor as it was aftermarket and it seems that everywhere I look that the plate should be, it is MIA. I have been using Mercruiser manual #8. The closest I can get is that it's a 3.7 L 4 cylinder with a 2 bbl carb and 4" heat exchanger.
So my question is are these temperatures acceptable given the fact that it is on the hose with a cold municipal water tap or should I replace the sending unit? I guess my concern is that I'm getting 130 F and the gauge isn't over 120 F. It seems that it doesn't even get hot enough to open the thermostat. Anything else I could or should check before a lake test or is this all normal with a new motor on a cold water supply and basically no load?
First, a little history. I have a 1986 Stingray SVC 195 SS that was my grandpa's when I was a kid. He had some engine trouble and had to replace the stock engine with a new engine. It only had approx. 5 hrs run time on it when it was parked where it stayed under multiple covers for 20+ yrs. The boat itself is in good shape except a few cosmetic touch ups that are needed. I'm currently getting it ready in hopes for a second debut on Memorial Day weekend. I have everything rebuilt on the engine and am just checking a few things.
I just ran the motor for approx. 15 min on the hose to check temperatures. I'm pretty gun shy with the 470 because I had a previous boat overheat and cause god knows what problems. The temperature gauge doesn't move a whole lot from cold peg and stayed just below 120 F. Took a few temp readings with an IR thermometer and found 130 F give or take at the sender unit. The water discharge out the back stays a little colder than luke warm. I get 1280 ohms of resistance on sender unit at outside temp and tested 366 ohms when it was reading 130 F on the thermometer. Before anyone says it, yes the wire was disconnected during these tests. The gauge tests out fine (pegs hot when grounded at sender). The coolant hose into the heat exchanger stayed around 135 F and the coolant hose out of the heat exchanger stayed around 100 F. Unpainted portion of manifold reads around 210 F. Is that too hot for that part? I have had to add oil a couple of times. The manual says it is going to use oil more during the break-in period which it is still technically in. I do not find oil in the coolant (stays bright and green) and oil doesn't become brown or milky.
Unfortunately, I have no SN for the motor as it was aftermarket and it seems that everywhere I look that the plate should be, it is MIA. I have been using Mercruiser manual #8. The closest I can get is that it's a 3.7 L 4 cylinder with a 2 bbl carb and 4" heat exchanger.
So my question is are these temperatures acceptable given the fact that it is on the hose with a cold municipal water tap or should I replace the sending unit? I guess my concern is that I'm getting 130 F and the gauge isn't over 120 F. It seems that it doesn't even get hot enough to open the thermostat. Anything else I could or should check before a lake test or is this all normal with a new motor on a cold water supply and basically no load?
