outboard question

[grt1]

I was going to put my little skiff in the lake today and when I got to the launch I figured I would start it before taking it off the trailer, so I put the motor into the water so the intakes were covered and started the engine. A few spurts of water came out from the water exhaust in the engine then nothing, so I thought maybe it worked on a thermostat and let it run for a few more minutes, I put it in gear and ran it faster, in both forward and reverse but no water came out. Not wanting to get out in the river and have the engine sieze up I pulled it out, took it home and went to town to check with the marina guys.

 

They suggested that maybe something like a bug had made it's home in the water tube from the engine and the one guy behind the parts counter thought the engine has a thermostat control for the water coolng system.

 

So I came home and put the ear muffs on , shoved a piece of wire up the water tube to clean it out then gave it a pull to start it. Water came out the tube and I let it run for 5 minutes with no problem encountered.

 

I thought the problem was fixed but then I started thinking (maybe a dangerous thing to do) that maybe the only reason the water was coming out was because the pressure from the hose is forcing the water up to cool the engine . When I tested it initially it was still on the trailer and not moving and hence not forcing water into the intake.

 

So my question is this, should the water be forced up by the impeller if it is motionless in the water (ie still on the trailer) or will I burn up the engine if I run it and the impeller isn't working properly and only the forward motion of the motor is responsible for the water being forced into the cooling system?

 

your thoughts please

[DRIFTER_016]

I have not had the hose pressure force water out of the tell tale before.

When I hook up the hose I don't get a stream until I start the engine.

The motor will draw water in while it is stationary. The boat does not need to be in motion.

[BFSC Kevin]

I have not had the hose pressure force water out of the tell tale before.

When I hook up the hose I don't get a stream until I start the engine.

The motor will draw water in while it is stationary. The boat does not need to be in motion.

 

ditto

[Big Cliff]

Sounds like you need a new impeller. DO NOT RUN YOUR ENGINE UNTIL YOU GET IT FIXED. Get someone that KNOWS what they are doing to fix it. New impeller for that engine about $25.00.

[ChrisK]

What Big Cliff said but if you are getting a good stream of water out of the ejection tube it sounds like you may of cleared the blockage. Fire it up a few more times with the water muffs on to make sure the water comes out consistently every time.

[Rattletrap2]

I had a 1986 20 H.P. Merc and if the impeller was weak, the garden hose could "assist" in forcing water out the tell-tale outlet. It would not come out with force though until the engine was running. Those blockages are very common and possibly the only problem you had. Is the water streaming out with force, or just softly running out when the engine is running? The second that motor starts, it needs to come out with force! One of the things I did not like, was that it shot straight down and was difficult to see when operating the boat. I put a 45 degree fitting on mine.

[DRIFTER_016]

The second that motor starts, it needs to come out with force! One of the things I did not like, was that it shot straight down and was difficult to see when operating the boat. I put a 45 degree fitting on mine.

 

Not necessarily.

It depends on if your engine has a thermostat or not.

The Yamaha I just finished working on for a buddy would have a fairly weak stream for 30 seconds to a minute and when the engine had warmed up enough to open the Tstat it would come out strong enough to drill holes in my driveway.

[aplumma]

water muffs are not acceptable to test for coolant flow. A bad impeller will release a piece of it and clog the telltale. Once cleared the bad impeller will let hose pressure past the seals and make the telltale look like it has pressure but it is from the hose. Put it in the water and see if the stream is normal. To be safe if you have not changed the impeller in 3 years it is due. Better safe than a seized motor.

 

 

Art

[grt1]

thanks folk. it was a used camp motor when I got it and I haven't changed the impeller in at least 4 years. I guess i'll take it to the shop tomorrow and get a new one put in.

[Big Cliff]

thanks folk. it was a used camp motor when I got it and I haven't changed the impeller in at least 4 years. I guess i'll take it to the shop tomorrow and get a new one put in.

 

Smart man!

[Flappn]

On this topic, my motor is spitting water however my over heating alarm is going off on my 1989 90HP Merc. It's in for an impeller...however I am not confident the impeller is the problem as it went into the shop spitting water? Is it possible the impeller has deteriorated and possibly not sucking up enough water? The Impeller hasn't been changed for at least 10 years.

 

Thanx

[aplumma]

On this topic, my motor is spitting water however my over heating alarm is going off on my 1989 90HP Merc. It's in for an impeller...however I am not confident the impeller is the problem as it went into the shop spitting water? Is it possible the impeller has deteriorated and possibly not sucking up enough water? The Impeller hasn't been changed for at least 10 years.

 

Thanx

 

It is always a good bet to start with the obvious problem them work back from their. With a 10 year old impeller it needs to be done regardless of the alarm. Their are ways to check the circuit after a known temperature is established as to whether or not you have a second issue.

 

 

Art

[DRIFTER_016]

On this topic, my motor is spitting water however my over heating alarm is going off on my 1989 90HP Merc. It's in for an impeller...however I am not confident the impeller is the problem as it went into the shop spitting water? Is it possible the impeller has deteriorated and possibly not sucking up enough water? The Impeller hasn't been changed for at least 10 years.

 

Thanx

 

There is a pretty good chance it is the oil level sender in your oil res.

Mine went on me out on the lake years ago and I figured out it was the problem by just un plugging the oil sensor wires. They remain that way to this day as they want you to replace the entire tank to replace the sensor. As doon as I unplugged the sensor the alarm stopped.

 

You do need an impellor replacement so getting that done is good.

If you still have an alarm situation try unplugging the oil level sender and see if it goes away. Remember to check your oil level manually if you do this so you don't run it out of oil.

 

PS my engine is a '91 90hp Merc so it should be the same or very close to the same as yours.