18hp evinrude. Running HOT! Leaking from carb. Wth!

[whitejd12]

Re: 18hp evinrude. Running HOT! Leaking from carb. Wth!

I've checked compression on it over a year ago. Don't remember the details, but would've remembered a problem. It's ran good in the past, and in the video from yesterday it seemed to be running great for about 1 minute, (don't you agree) until it heated up. Sounded good, had good power, was idleing etc. I'm pretty sure it's not pumping water very well. If I can figure that out, I think it'll be great!! Here's the video again.

 

[whitejd12]

Re: 18hp evinrude. Running HOT! Leaking from carb. Wth!

OK, here's the video. Like you'll see, it was pumping water and it was squirting out of thermostat housing. So, what's going on?? Hopefully someone has some ideas. BTW, the head and thermostat housing, etc was very hot to the touch after that little bit. Is it supposed to be? Could that missing oriface screw and washer on the carb yesterday have caused the motor to just quit?

 

[racerone]

Re: 18hp evinrude. Running HOT! Leaking from carb. Wth!

When the plug fell out the fuel all drained from the carburetor bowl.----Motor would have difficulty running well.---------Put it on the boat and try again.

 

[HighTrim]

Re: 18hp evinrude. Running HOT! Leaking from carb. Wth!

Agree with above^^^ The missing plug could very well have been the cause of you dying on the water while at WOT the other day.

Has nothing to do with the overheat though, if it did overheat.

I personally feel like there is an issue with your cooling circuit still. Looked more like misting than a steady flow.

Maybe water line is partially pinched in grommet? Were they greased? maybe partial blockage? Was any of the old impeller missing? Did you flush water lines at all? How was the impeller housing and plate? Overly worn? Vent in impeller housing open and clear?

Water intake free of debris and clear?

My advice would be to drop gearcase again and have another look see before hitting the water. Better safe than sorry.

Maybe Im not seeing the video well though, and there was more than mist and steam.

 

[w2much]

Re: 18hp evinrude. Running HOT! Leaking from carb. Wth!

You need a bigger barrel to run that thing in. Exhaust bubbles and turbulance are prventing a sufficient amount of water to be sucked up into the pump. I have run smaller motors in little buckets like that and it worked fine. My 18 did not pump water in the cat litter bucket either .No way you are going to get enough water to the pump from that small bucket.

 

[whitejd12]

Re: 18hp evinrude. Running HOT! Leaking from carb. Wth!

Chris,

Watch the video again. Look close at exhaust outlet, there was definitely water coming out, not just steam. And along with the steam, it was squirting pretty good, I think, out the thermostat housing. When I serviced the lower unit during restoration I used Sierra Marine part #18-3377, water pump kit w/o housing.

To try to answer your questions, let me think back to last year.....no part of old impeller was missing, I cleaned housing up good, don't remember any problems, installed new plate from kit, Yes water intake is clear. I did not flush water lines, ?????. That's all I can remember, w/o lowering unit again and looking.

 

[whitejd12]

Re: 18hp evinrude. Running HOT! Leaking from carb. Wth!

Also, is it normal for the head and thermostat housing, etc to get really hot to the touch? Maybe I'm over-reacting.

And, maybe like w2much said, it'll pump more water when it's on the water and not in a small water container. IDK?

 

[kfa4303]

Re: 18hp evinrude. Running HOT! Leaking from carb. Wth!

I agree that you need a larger test tank. I have several 18-20hps of this era, but I use a large trash can to ensure that there is plenty of water. A 55 gallon barrel would be even better. Yeah, it's a pain, but it's the only way to do it properly. You can see why they invented "muffs" for modern motors too :/ All part of the "charm" of running vintage motors. Once you have replaced the carb needle and put the motor in a large tank wit water filled to within about 1"-2" of the exhaust port on the back, fire her up and see how she runs. If she tries to die, manually squeeze the fuel primer bulb, if the motor responds you have a problem with the fuel pump. However, if there is no change, you may have an issue with one of the ignition components overheating and failing, most likely one of the coils. If you have compression (+90psi), spark (can jump 1/4" gap on both cylinders using Champion J6C plugs) and fuel it will run.

 

[HighTrim]

Re: 18hp evinrude. Running HOT! Leaking from carb. Wth!

w2much makes a very good point. Did not really look at the test tank, but it is much too small, and don't think the water pump is even submerged. The pump is not self priming, the water line needs to almost be a few inches below exhaust relief like it would be on the water.

I would take it out again and try, now that you have remedied carb. Just keep an eye on the exhaust relief.

It will get hot, but you should be able to hold your hand on the head for a 3 count. If you splash water on it, and it sizzles, much too hot.

 

[whitejd12]

Re: 18hp evinrude. Running HOT! Leaking from carb. Wth!

Ok, well I haven't checked it yet, but what if I can't hold my hand on the head and/or water sizzles on it. What then? Just so I know what to do next if I find that to be true. Thanks.

 

[geoffwga1]

Re: 18hp evinrude. Running HOT! Leaking from carb. Wth!

Yes. Though i don't know about the smoking hot bit,unless ity was cos it was running too lean.

 

[racerone]

Re: 18hp evinrude. Running HOT! Leaking from carb. Wth!

If water sizzles on the block it is too hot !!------That sizzling is caused by a lack of cooling water and not from running too lean !!

 

[whitejd12]

Re: 18hp evinrude. Running HOT! Leaking from carb. Wth!

OK, well I'm not gonna be able to get on the lake again till next weekend depending on the weather. I will post an update video next weekend. Thanks for all your help guys.

 

[KRH1326]

Re: 18hp evinrude. Running HOT! Leaking from carb. Wth!

You need a bigger barrel to run that thing in. Exhaust bubbles and turbulance are prventing a sufficient amount of water to be sucked up into the pump. I have run smaller motors in little buckets like that and it worked fine. My 18 did not pump water in the cat litter bucket either .No way you are going to get enough water to the pump from that small bucket.

This ^^^^^

 

[boobie]

Re: 18hp evinrude. Running HOT! Leaking from carb. Wth!

Agree with the above. I just caught the pic of it in the barrel. It's to small.

 

[whitejd12]

Re: 18hp evinrude. Running HOT! Leaking from carb. Wth!

OMG everyone! I think I may have figured out the problem. My OCD (as my wife would say) was kicking in, so I was reading "Leeroy's Ramblings" and it hit me, you're gonna laugh, I'm a little embarrased. As you know I've been doing an complete restoration of this motor, which included a new paint job, the entire lower unit and prop, not to mention an automotive quality paint job on the cowling. Well, when I painted the lower part of the motor, I taped off certain things (see where I'm going here?) with blue painters tape, (which is the same color blue that I used on the motor). One of the areas I taped off (guess, guess) was the water intake screen on the cold water intake right behind the prop. And with the tape being the same color as the motor I never noticed that I had never removed the blue tape. So if I had to guess, I'd say that that screen being completely covered with blue tape was the reason I was not pumping much water and running hot. RIGHT!?? Stupid, stupid, stupid!!

I just went out in my garage, (yes, at almost midnight, did I mention OCD?!) and w/a flashlight and a little utility knife, removed a little piece of blue tape. The easiest and maybe most important thing I've done to this motor since I started.

Alright, I'm going to bed now. I can't wait to go test this thing again now. :joyous:

 

[HighTrim]

Re: 18hp evinrude. Running HOT! Leaking from carb. Wth!

Gotta love the "AHA!" moments!

 

[whitejd12]

Re: 18hp evinrude. Running HOT! Leaking from carb. Wth!

I am thinking about ordering a new water intake screen and plug, since the one in it is probably 42 years old. They're still available. Question is, is it a big (possible) job getting the old plug out in order to remove and replace the screen?? Thanks.