1999 Mercruiser overheating

[kcrsq]

1999 Mercruiser 5.0 Alpha 1, Bayliner Capri
I made a mistake by running engine for 3-5 minutes while winterizing ( I know stupid,huh). Boat ran great all summer.
After running boat without water I decided to replace impeller just in case before next season. Didn't put ears on to see if it was overheating or not just wanted to change it. I just replaced it 2 years ago.
Anyways, pulled out old impeller and it and housing looked great. Replaced anyways. Not sure if I put impeller in backwards or not but I did leave a "tool"(supposed to be used to push seal down, not leave on) on shaft. It was a little round plastic piece that went over the seal around shaft above housing. Thought it was another seal. Ran boat (with water) and overheated. Cheated intake hose on thermostat housing and it was dry. Dropped lower end again and took "tool" off, impeller had a groove worn around center(too tight). Old impeller looked better so I put it back on.
Still overheated to about 230*. I took thermostat out and overheated to about 190*. Put new 160* thermostat in and still overheats.

So here are my problems-runs about 190*, barely spitting out water on starboard exhaust, none on port side, water flowing out prop, vent holes, and up behind lower end (by where that cable hooks up), starboard exhaust manifold gets pretty warm, port side gets too hot to touch. After running for about 5 min. I can hear a grinding, squeal from crankshaft pulley area (I don't think it's from circ. pump) pretty sure I heard it all last year. When I take water drain plugs out water does drain.

So I'm thinking the motor is getting water but not enough. I'm gonna put another new impeller on and make sure water tube is lined up correctly. That way I'll have new thermostat new impeller and be positive the water tube is not kinked.

Anybody have any other ideas or recommendations. Especially if replacing impeller again and checking water tube doesn't work.
I wouldn't think the lower end wouldn't have gone on with water tube not right...also I know I have impeller on backwards. If looking at housing upside down I put in clockwise. I'm pretty sure I need to spin counter-clockwise if putting into housing then it would be clockwise when installed.

 

[cr2k]

Re: 1999 Mercruiser overheating

Correct. Usually put the impeller on the shaft making sure the drive piece is engaged. Then turn the vertical drive shaft clockwise while pushing the housing down over the impeller. Putting the impeller in the housing first you probably didn't get it on the drive shim and it didn't turn the impeller. Impellers should be changed every 2 years regardless. If they sit they take a set and the rubber gets hard, if they get used they wear. Even if it looks good it can be bad if it's old. Use some glycerin or silicone spray to lube the impeller so it it easier to stuff into the housing.

 

[kcrsq]

Re: 1999 Mercruiser overheating

Okay, now with the new 160* thermostat it runs at 180*??? Water is flowing normal and heavy out both exhaust sides. I had the impeller on backwards and possibly the water tube crooked...
Now, with engine off the prop will spin freely in N, in WOT forward prop spins freely CW and stops CCW, but in WOT reverse it spins freely CCW and CW-it will catch but then release CW. If I trim up I can reach the shift shaft(silver elbow coming from lower end) and move up and down-not sure if that's right. also it's about 3/8 " away from top end "curved" piece...That top piece that's curved it goes into also has a little up and down play...Also when running it will pop into forward and spin and reverse and spin???
When I installed lower end I had it in forward and the shift shaft pointing forward-although, when I took it off I moved the SShaft to point forward it was pointing to the starboard side a hair...
The lower end slid right on with no force-surprisingly...

1. So my question is-why is it running 180 with a 160 thermostat. Over the summer it ran lower I think around 160-170.
2. Do I need to drop lower again and make sure the shift shaft is still pointing forward, why is their play, is it normal, it points forward now when throttle is forward. I heard I might be off just a tooth...
3. If so how do I tell if shift shaft is in forward when off before I reinstall?
thanks

 

[achris]

Re: 1999 Mercruiser overheating

That's Gen II leg, you shouldn't have to remove the shift shaft from the lower housing to get at the water pump. It comes away with the lower, there is no intermediate shaft. A little vertical movement on the shift shaft (in the gear housing) is normal, it's just splined into the shift crank.

I would drop the gear housing off again and check a couple of things.
1. Check that the housing selects and fully engages forward and reverse.
2. Re-install the water pump housing using the correct alignment pins for it. If you don't use the pins you can end up with a few different problems. Not pumping enough water, housing wear from contact with the drive shaft, drive shaft wear from contact with the housing.
3. The V-seal is installed correctly, again with the correct installation tool.

If you didn't have the upper housing off then the shift cable to upper shift shaft should be ok...

Chris.........

 

[stonyloam]

Re: 1999 Mercruiser overheating

Your outdrive is shifting correctly (almost). You are not "off by a tooth", if you were the control would jam. There is no washer in the gen II so that is not a problem. Sounds like you just need to adjust your shift cable a little to get it to shift solidly into R. They talk about adjustment here, about page 90: http://www.perfprotech.com/store/app_themes/ppt/images/tech-specs/alpha-shift-adjust.pdf Good luck.

 

[kcrsq]

Re: 1999 Mercruiser overheating

I'm calling the short "L" shaped rod of the front of the lower end the shift shaft. Maybe thats not what its called. Thats what I aimed forward(unless it got bumped) when reinstalling.
Also how would the cable get outta adjustment just by dropping the lower?
What is the V-seal?
Never heard of alignment pins-I sat housing on and the 4 bolts will only go on one way?

 

[kcrsq]

Re: 1999 Mercruiser overheating

If the v seal is the one that goes over the shaft and sets on top of the housing-I put it on with that round plastic seating tool(and took it off). It flares out on one end, or maybe you could say it has a lip-I put it on with the lip up, tapered down. Thats how the old one came off. But I put it on last year

 

[kcrsq]

Re: 1999 Mercruiser overheating

Also thank you guys. I'm not second guessing anyone it's just that this has turned into a nighmare

 

[achris]

Re: 1999 Mercruiser overheating

Are you using the service manual? The proper manual, not the rubbish seloc/cylmer things. All the parts I name are 'by the book'. And yes, the water pump housing COULD be just bolted down with the 4 bolts, but the pump housing, gaskets and base plate will not be lined up correctly with the gear housing..... You WILL have problems if you don't use the alignment pins, as per the book....

Chris......

 

[stonyloam]

Re: 1999 Mercruiser overheating

Also when running it will pop into forward and spin and reverse and spin???

1. So my question is-why is it running 180 with a 160 thermostat. Over the summer it ran lower I think around 160-170.
2. Do I need to drop lower again and make sure the shift shaft is still pointing forward, why is their play, is it normal, it points forward now when throttle is forward. I heard I might be off just a tooth...
3. If so how do I tell if shift shaft is in forward when off before I reinstall?
thanks

When running there is probably enough resistance from the prop to keep it locked in gear.

The 160 thermostat opens at 160 F, so the average temp of the engine will be higher than that. I do not have a manual, but would think 180 is well within the operating temp range for your engine.

No. The lower shift shaft (L shaped rod) only has something like 6 or 8 splines, so if it were "off a spline" it would be 40 to 60 degrees off, so you would know it. And the control lever would be jammed.

Turn the lower ss all the way clockwise (should point straight ahead), turn the prop CCW till it locks and put a bungee on the prop to hold it there.

 

[jimh1626]

Re: 1999 Mercruiser overheating

A 160 thermostat starts opening at the temp and will fully open at 185. So your 180 seems normal.