1976 johnson 15hp new impeller but no water telltale, not hot

[oldguye]

Hi All,

I just put a new impeller in my '76 Johnson 15hp yesterday. It was pretty easy, I read a lot of posts/threads and followed the 'machinists' stuff he posted with great pics.

OK, the old impeller had a permanent curl, I had previously removed the water cover over the thermostat, taken the thermostat out, cleaned everything up, cleaned the gasket surfaces, checked the thermostat (it opens & closes), then I put it back together (the cover latch is a 'purple son-of-a-bitc*') using rtv silicone (very light coat to be sure I did not clog anything up,I hope).

I put in a new impeller in and greased it (lightly) on the impeller vanes. I put it back together and started it. The motor fired up idled and ran great, BUT, almost no water coming out exhaust (tough to tell as I was on earmuffs), a little coming from the water discharge holes just above the a/v plate, and NO water out the big discharge below the powerhead, even when I revved it up in neutral; yet, I used my hand to check the water cover, the thermostat area of water cover and both sides of the motor where the pistons are.

Using my hand on the piston area (inspection plate?..one on each side of the motor), it got warm/hot, but not enough to make me remove my hand, then (presumably, when the thermostat opened) it cooled down to warm. I let it run for about 10 minutes using my hand and feeling the small amount of water out of the discharge (warm, not hot).

HOWEVER, the little drain hole for the "1/2 cup of water or so" (can't remember where I read that in the forums), was shooting water out like a telltale and it drained out after I shut the motor at a pretty good clip (I made that hole 3/16" instead of 1/8").

OK, in reading a lot of old posts this morning I found one that says if "the thermostat is stuck open or not sealed real tight you'll get almost no water until you throttle up".

My questions:

1. Am I worried about nothing?

2. Did I somehow screw up in making that drain hole a 1'16" bigger?

3. Will testing it in a barrel give me a better 'telltale' out of the big hole below the powerhead?

4. Should I also have put in a new thermostat (old one was working fine - opened & closed) as the rubber gasket around the thermostat had a slight 'pinch' from it's previous installation. Also, I believe this was the first time the water cover had been off.
5. The old water pump housing had no gaskets below or above the stainless steel plate below the impeller and I reassembled it like that after proper cleaning. Also, I got the plate in correctly (the way it was when I opened it up - I only replaced the impeller). Should there have been gaskets?
6. I DID NOT blow out the inlet/outlet areas but I did use a hose with a 1/4" width tube to put water in both inlet/discharge when I had the water cover & thermostat off. Was this a screwup of one, two, or no parts?

I am hoping you guys can steer me correctly, I don't want to ruin my motor from overheating it, but, as I said the motor ran nice, the discharge water (what little there was - most came shooting out the drain hole while I had the hose going on the muffs - that drain hole water looked like a thick 'telltale' even with the motor not running but the hose & earmuff on).

This was my first impeller changeout, I'm OK on electrical & carb/fuel (I read the manual and follow the forums) but I'm a rookie at the water pump stuff.

Thanks ahead for all responses - this forum is great.

Thanks,

Oldguye

 

[Daviet]

Re: 1976 johnson 15hp new impeller but no water telltale, not hot

I don't beleave your engine came with a tell-tale, unless someone installed it. Are you talking about the exhaust port in the exhaust housing? On through hub exhaust, like yours, when running on a hose the water will mostly exit through the prop because the exhaust housing does not fill up with water like it does when submerged in water. If the engine is staying cool to the touch, I would say you are OK.

 

[oldguye]

Re: 1976 johnson 15hp new impeller but no water telltale, not hot

I don't beleave your engine came with a tell-tale, unless someone installed it. Are you talking about the exhaust port in the exhaust housing? On through hub exhaust, like yours, when running on a hose the water will mostly exit through the prop because the exhaust housing does not fill up with water like it does when submerged in water. If the engine is staying cool to the touch, I would say you are OK.

Well, unless I'm blind (and I'm not) the only way to respond to someone responding to me is with a quote. DUMB, DUMB, DUMB.

Thank you for your response.

Anyhow, I know this does not have a telltale, I said that the drain hole for extra water out of the housing is shooting water like a telltale when I turn on the muffs/hose.

I am inclined to believe something is wrong whether hot or not.

Ideas anyone?

Thanks,

Oldguye

 

[AlTn]

Re: 1976 johnson 15hp new impeller but no water telltale, not hot

run it in a barrel with the water level a few inches below the exhaust relief holes, if it doesn't heat up..good to go..btw..the thermomelt stix used are 125 deg. and 165 deg...125 melts....165 doesn't...wear plate gaskets..none used, some folks seal the bottom edge of the w/p housing where it rest on the wear plate..enlarged drain hole probably did more good than harm...as Daviet expressed, if it's not getting hot it's serving its function....try www.leeroysramblings.com for info as well

 

[Davem3]

Re: 1976 johnson 15hp new impeller but no water telltale, not hot

and on mine , i did the whole water pump, not just the impeller, the new SS housing inside it, is nice , much better than the old system they used to have

 

[the machinist]

Re: 1976 johnson 15hp new impeller but no water telltale, not hot

If I understand this right the water you have is coming out the 1/8" drain hole on the front LH side of the lower unit just above the propshaft/gearbox enlarged section of the lower unit, This is a drain for any water that is left inside the exhaust housing after you take it out of the water to keep it from freezing if in COLD winter weather. There could be water coming out here that has already been thru the motor when you have are running it on muffs, (1) UNLESS you are running city water full blast & blowing water past the upper water pump/driveshaft seal.

(2) OR you could have a folded over grommet in the upper outlet of the water pump when you put it back together & tried to align the copper water tube into the water pump outlet.

If you have any doubt, convert it over to a tell-tale water overboard system. As I cover in my article http://www.leeroysramblings.com/water_circulation.htm

 

[oldguye]

Re: 1976 johnson 15hp new impeller but no water telltale, not hot

If I understand this right the water you have is coming out the 1/8" drain hole on the front LH side of the lower unit just above the propshaft/gearbox enlarged section of the lower unit, This is a drain for any water that is left inside the exhaust housing after you take it out of the water to keep it from freezing if in COLD winter weather. There could be water coming out here that has already been thru the motor when you have are running it on muffs, (1) UNLESS you are running city water full blast & blowing water past the upper water pump/driveshaft seal.

(2) OR you could have a folded over grommet in the upper outlet of the water pump when you put it back together & tried to align the copper water tube into the water pump outlet.

If you have any doubt, convert it over to a tell-tale water overboard system. As I cover in my article http://www.leeroysramblings.com/water_circulation.htm

AHHHH,

I did have the water up pretty high and the hose bib there has the full force of city water. I will try it again in a barrel AND on the muffs with low water pressure.

I thought about the grommet but it slid in very easily when I was putting things together. I'll try to get some pics today when I retry it.

I really want to express my appreciation to all of you guys who responded and, machinist, you are like a valuable reference book only better. We all owe you tons of gratitude for your concise advised.

Thanks again.

Oldguye

 

[Davem3]

Re: 1976 johnson 15hp new impeller but no water telltale, not hot

If I understand this right the water you have is coming out the 1/8" drain hole on the front LH side of the lower unit just above the propshaft/gearbox enlarged section of the lower unit, This is a drain for any water that is left inside the exhaust housing after you take it out of the water to keep it from freezing if in COLD winter weather. There could be water coming out here that has already been thru the motor when you have are running it on muffs, (1) UNLESS you are running city water full blast & blowing water past the upper water pump/driveshaft seal.

(2) OR you could have a folded over grommet in the upper outlet of the water pump when you put it back together & tried to align the copper water tube into the water pump outlet.

If you have any doubt, convert it over to a tell-tale water overboard system. As I cover in my article http://www.leeroysramblings.com/water_circulation.htm

Leroy, that website is a serious saver, thank you for all of your knowledge, and nice to meet you

 

[oldguye]

Re: 1976 johnson 15hp new impeller but no water telltale, not hot

Leroy, that website is a serious saver, thank you for all of your knowledge, and nice to meet you

Leroy,


Your Ramblings should be required reading for anyone wishing to fish or boat and ESPECIALLY if they want to work on their own stuff.

You are the type of person that is becoming darn near extinct in America - where manufacturing and making things with pride and making things work (while receiving a wage which allows one to do more than barely get by) used to be what our country was known for.

Not quite the same as when we were young. And that is a shame. IMO 'vote em all out' and get some in that care about America's people first..not everyone else first (see our never-ending trade deficit).

Sorry about the rant, just my two cents.

Thanks again,

Oldguye

 

[OptsyEagle]

Re: 1976 johnson 15hp new impeller but no water telltale, not hot

I believe you need to run it in a barrel to see water out the exhaust hole. Even in a barrel you will only see a spray after about 10 to 15 seconds, when the thermostat opens up. Sounds like your motor's cooling system is working just fine, but try it in a barrel to be sure.