18 HP Evinrude spent a week on the bottom of the lake

[White Feather]

Hello Gents,

A week ago last Saturday my boat motor wound up on the bottom of the lake. I hit a submerged stump at full throttle kicking my 18HP Evinrude up so hard it pulled free of the transom and did a swan dive off the back of the boat. It was followed closely by the battery, which was tethered to the motor by the battery cable, almost clipping my son in the head as it flew past.

Long story short, the following week I made a grappling hook out of some rebar and managed to snag the battery cable, which thankfully was still firmly attached at both ends, and pulled the old girl up. The motor had been under water for one week.

After getting it home I removed the spark plugs and carburetor then turned the motor upside-down to drain as much water out as possible. I also removed the starter and solenoid, and then popped off the flywheel so that I could get at the points.

Other then changing the oil in the foot and spraying the cylinders down with WD40, all I did was disassemble and clean the carb and starter motor, and dry off the points. I put it all back together Sunday afternoon and the motor actually started relatively easily.

We took it back to the lake and all seems fine except for a “hiccup” and surging at full throttle. I haven’t been able to track that down yet. It starts and idles fine. In fact, it actually seems to have more gitty-up from idle to being on plane then it ever did. Once there however the problems start.

Any suggestions as to what to check next? I'd appreciate any assistance I can get.

 

[iwombat]

Re: 18 HP Evinrude spent a week on the bottom of the lake

All the standard diagnostics apply.

Spark check and compression check and let us know what you find.
Let's find out what it's not before speculating on what it is.

 

[ddennis]

Re: 18 HP Evinrude spent a week on the bottom of the lake

is it making any "funny" or unusual noises? I am still a newbie, but I would guess something electrical..did you replace any of the electrical parts or just dry them out...mainly in the ignition area? Ie coil or condensor? Check to see how strong the spark is...

I would assume that since it is running that well it shoudlnt be too major..but that will be more for the experts to say.

Glad your son is ok and glad you were able to recover the motor! Watch out for them stumps! LOL!

 

[tashasdaddy]

Re: 18 HP Evinrude spent a week on the bottom of the lake

obviously you were in fresh water here's a link on sunk engines. so far you have been extremely lucky. glad son is ok.
http://www.brokeboats.com/sunk.html

 

[tashasdaddy]

Re: 18 HP Evinrude spent a week on the bottom of the lake

i also think i'd do a decarb, and clean the motor out, it's like an enema. the motor was running when it to the dunk, so there's water in there, the crud got wet, get it out. here's another link, you can use seafoam in a spray bottle instead of buying Deep Creep same stuff.

http://forums.iboats.com/bbBoard.cgi?a=viewthread;fid=36;gtid=1035563

 

[steelespike]

Re: 18 HP Evinrude spent a week on the bottom of the lake

What year?
You might add a little extra oil to the gas for a tank.Run it a lot just to be sure the water is all gone for the crank case.There is a slim chance it could be hiding in the main bearings.As far as the hiccup & surging my guess is still a little water in the fuel system.

 

[F_R]

Re: 18 HP Evinrude spent a week on the bottom of the lake

You got real lucky in several ways. In addition to those already mentioned, you are lucky it didn't bend the connecting rods as so often happens when a motor takes a dive at full throttle. Water won't compress and something has to give.

Can you describe the hiccup better? Does it seem like you are running over obstructions in the water? That would be the clutch dog, and probably just a coincidence that it is happening right now.

 

[iwombat]

Re: 18 HP Evinrude spent a week on the bottom of the lake

Surging could easily be a spun prop too. And likely since it hit something very hard.

 

[tashasdaddy]

Re: 18 HP Evinrude spent a week on the bottom of the lake

all good points.

 

[iwombat]

Re: 18 HP Evinrude spent a week on the bottom of the lake

Still, I've always had more success in getting data to find out what it isn't before speculating on all the things it MIGHT be.

 

[jimmbo]

Re: 18 HP Evinrude spent a week on the bottom of the lake

Coils might have gotten water in them if they are old and the potting is cracked. Did you clean out the fuel pump, strainer and fuel lines? Not meaning to critize, while spraying the cylinders with wd40 to prevent rusting isn't a bad idea, it is the bearings in the crankcase that really needed to be protected. Consider yourself lucky that the motor at WOT didn't join you in the boat.

 

[White Feather]

Re: 18 HP Evinrude spent a week on the bottom of the lake

That’s all good information. I appreciate it very much and I appreciate your kind words in regards to my son. We were very lucky indeed.

Now for some additional info. The serial number on the transom mount and on the motor itself is 15028-18692. That shows to be a 1957 Evinrude 18HP. Up until last summer, that’s exactly what I thought it was, and what I’ve purchased parts for over the last 15 years.

However, last summer when I tried to find a replacement upper cowling for it (we lost it in the same lake) I discovered that the upper and lower cowlings at least were not from a 57 Rude.

Further investigation revealed I had a Johnson/Evinrude hybrid. The power head and parts of the frame are 1957 Evinrude. The foot, the upper and lower cowlings, and parts of the engine (starter, carb, and ignition/flywheel) are off a late 60’s 18 or 20 HP Johnson painted to match the rest of the motor. (By the way, if anyone out there needs an upper cowling for a 1957 18HP Evinrude Golden Jubilee I have a nice one cheap.)

Compression seems fine via the finger-in-the-hole check. Spark looks good and has a nice “click” to it so I believe the coils are OK too. No “funny” noises to speak of. I did clean out the fuel filter, (a small inline I purchased from AutoZone.) I blew through all the fuel lines too but I did not take the fuel pump apart.

The “hiccup” is reminiscent of what happens at low idle when the idle mixture isn’t adjusted properly. Not exactly like running over anything. It sort of coughs for a split second then resumes running normally.

The surging happens only at full throttle. The RPM’s will not remain constant and it’s quite noticeable, but it only happens at full throttle. It gets going from a standstill to wide open nice and smooth. Very strong.

In the past when we have sheared the pin in the prop it’s like being in neutral. I’ll double-check that but I’ll be surprised if it’s sheared.

I’ve heard of using Sea Foam to decarbonize. It had not occurred to me to try that approach for getting any remaining moisture out of the crankcase but it sounds like an excellent suggestion. I’ll give it a go.

The coils look good, but the spark plug wires and boot ends show some age. The plugs wires are in a plastic sheath from where they emerge from the coils all the way down to within a few inches from the plugs. I suppose there could be some moisture hiding in there causing crossfire.

Additionally, when we took it out for a spin last weekend we ran it for almost two hours burning up over 3 gallons of gas. I’m thinking that should have been enough to run out any water in the fuel system or crankcase but I could be wrong.

I hear you about using a methodical process to eliminate possibilities. Hopefully my descriptions here will help narrow things down. I look forward to hearing everyone’s additional input.

Thanks again -

 

[iwombat]

Re: 18 HP Evinrude spent a week on the bottom of the lake

You really ought to do a proper compression check. The possibility of a warped head from taking on water at WOT mentioned earlier is pretty real. You could have a leaky head gasket that's only giving you symptoms at full throttle. A compression check will find that out.

 

[White Feather]

Re: 18 HP Evinrude spent a week on the bottom of the lake

I can do that. What compression is considered good compression? 40, 50 PSI?

 

[tashasdaddy]

Re: 18 HP Evinrude spent a week on the bottom of the lake

that age around 100 and should be with in 10% of each other. here's something else to consider.

http://www.iboats.com/bbboard/bbBoard.cgi?a=viewthread;fid=28;gtid=818798;gpid=818802

 

[Willyclay]

Re: 18 HP Evinrude spent a week on the bottom of the lake

You may not have identified iwombat's suggestion above that the surging could be a "spun hub". I had that experience once and it was a little difficult to recognize. Not as straight forward as a broken shear pin. If you have a spare prop, try it out next time on the lake. If not, you may need to have a prop shop look at it or buy a replacement. Sounds like you did a great job recovering and reconditioning your motor. Keep us posted.

 

[Chinewalker]

Re: 18 HP Evinrude spent a week on the bottom of the lake

In addition - it is possible the head gasket is partially blown, particularly since the motor went underwater running. Could be dropping a cylinder periodically as water or steam enters the combustion chamber. If the other points don't pan out, check the head gasket...
- Scott

 

[mikesea]

Re: 18 HP Evinrude spent a week on the bottom of the lake

are you still using the starter,if so,I would take it off and disassemble ,cleanup.water often gets in there and after a time tings start to go bad.Its not a hard job,just take the casing off and spray it and brushh assembly with ELECTRIC CLEAN or the like.You want something that will help remove moisture.The electric clean suff is good under the flywheel,if you need to,get back in there

 

[White Feather]

Re: 18 HP Evinrude spent a week on the bottom of the lake

Thanks Admiral. That's excellent information. I read Joe's procedure some time back for adjusting carbs and it helped solve a problem then on this same motor. By the way, this web site is a great resource. Better then any I have come across.

As for my current problem, I wouldn't think it has anything to do with compression. It runs too good. Also, I don't believe the motor was running wide open when it submerged. After we hit the stump, I had time to turn completely around in my seat up front and see not only the battery flying past my son's head but also see the motor sink. Maybe two or three seconds elapsed from impact to sinking. I think the throttle had time to close before copious amounts of water got sucked into the combustion chambers.

To my mind, the problem almost certainly has to be fuel or ignition related. I haven't taken apart the fuel pump, nor have I removed the reed valve plate. If the high speed surging persists after running the motor again this coming weekend, that's probably going to be my next direction to go.

Unless of course you professionals can steer me in a different direction. I'm open for any ideas.

Thanks again -

 

[iwombat]

Re: 18 HP Evinrude spent a week on the bottom of the lake

Doesn't have to go down at WOT to blow a head gasket. Just takes filling up most of one chamber with water and trying to compress it.