1993 Mercury 150 XRi

[Silversound]

I purchased a 93 Astro F18 Quickfire with a Mercury XRi 150. I changed the steering cables and the gear oil in the lower unit and put two cans of seafoam in the fuel tanks. I was wondering if 160 is the correct operating temperature for this motor. I rode yesterday and the oil temp light came on but the temp gauge indicated 160 and never went past that. This was right after I left the boat launch and the water pump appeared to be pumping normal. I have a pressure gauge but it is not working and I am not sure why.

I am also wondering why the boat is sluggish to plane, no cavitation. The prop is a stainless Tempest Plus 25p and it has a jack plate. After it planes off it runs very strong and fast. The motor idles well and starts first crank every time.

 

[Chris1956]

Re: 1993 Mercury 150 XRi

I never thought those motors had an "oil temp" light. You should have a low oil alarm. If the motor tank kept full? If not you have some sort of pressure problem on the remote oil tank in the boat.

A 25P prop is usually used on speciality high speed, light boats. It may be too "tall" for your boat. what do you have?

Motor thermostats usually open at 140*F, so 160 on the gauge is fine.

 

[Silversound]

Re: 1993 Mercury 150 XRi

I never thought those motors had an "oil temp" light. You should have a low oil alarm. If the motor tank kept full? If not you have some sort of pressure problem on the remote oil tank in the boat.

A 25P prop is usually used on speciality high speed, light boats. It may be too "tall" for your boat. what do you have?

Motor thermostats usually open at 140*F, so 160 on the gauge is fine.

Thanks for the reply. I decided to check the spark plugs and when I did I realized that one of the spark plug wires was not connected. I was glad to see that, went in the water and the boat planes very fast with no hesitation at all. I feel kind of dumb that I did not check that before, I took the cowl off a few days ago and I felt a snag as I removed and I thought nothing of it. That must have been when the wire came unplugged.

I forgot to mention that the oil injection was removed by the previous owner.

When I rode today the temp gauge went up to 180 degrees so I put it back on the trailer. I am not sure when the last time the water pump was replaced by the previous owner. It has good pressure but I guess it may not be working properly. I purchased the entire water pump kit instead of just the impeller. I will have it changed tomorrow afternoon.

 

[Faztbullet]

Re: 1993 Mercury 150 XRi

You need to replace impeller and check the t-stats. The boat you have has a pretty good hull under it as its a modified copy of a Ranger. A 25pitch is about right for that hull..

 

[Silversound]

Re: 1993 Mercury 150 XRi

You need to replace impeller and check the t-stats. The boat you have has a pretty good hull under it as its a modified copy of a Ranger. A 25pitch is about right for that hull..

Thanks, I am enjoying it. I just need to get rid of some minor issues. I bought the whole water pump kit and I will change it Friday afternoon. Yeah after realizing I had a plug wire disconnected the boat planes very fast with no hesitation.

 

[Faztbullet]

Re: 1993 Mercury 150 XRi

When you replace impeller replace all the gaskets,wear plate and tighten nuts to proper torque so housing dont warp... all nuts and screw tighten to 50 inch lbs.

 

[Silversound]

Re: 1993 Mercury 150 XRi

When you replace impeller replace all the gaskets,wear plate and tighten nuts to proper torque so housing dont warp... all nuts and screw tighten to 50 inch lbs.

Thanks for that information, I would have tightened it without a torque wrench. I have a ft lbs torque wrench but not a inch lbs, I may have to borrow one or purchase one.

 

[Chris1956]

Re: 1993 Mercury 150 XRi

You can convert inch pounds to foot pounds mathmatically. 12 inch-pounds = 1 ft pound.

You might also rebuild the poppit valve, while you are at it. It is low on the block on the starboard side. Removing the lower starboard cowl will expose it.

 

[Silversound]

Re: 1993 Mercury 150 XRi

Thanks for the reply, my torque wrench does not go that low even to convert it. I did not change the pop it valve, how would I know if it is bad?