1994 40HP Evinrude - Hit rocks, what to do first.

[sfmeyer]

Only and certainly is myself to blame but my spotters directed me over a large rock and it clipped my skeg and aluminum prop as I was running at WOT on the river this weekend trying to get back to camp in gusting winds. I am figuring the lower unit is shot, but I was hoping at the least I could better understand what happened mechanically. Or by some miracle, this LU is salvageable and someone may have had a similar experience and can guide me on what to look for.

Immediately after the short-lived impact at 28MPH/WOT, the motor was still running but I shut it down by pulling the kill switch.
I recall an oily discharge just after impact, but didn't pay too much attention to it as I immediately used my electric to get to safety and inspect the damage.
The skeg has a small gash in it, and 2/3 blades are banged up.
I found the prop would spin freely in both directions, forward and reverse.
There was no more oily discharge, so I put in the neutral, and it started right up.
While running at idle in N, I engaged F, and the motor immediately locked up, never to be started again.

My model tiller has a 3 position rocker for Reverse-Neutral-Forward and the starter will only engage in the center Neutral position. Attempting to start the motor in N results in very abrupt turn/click of the motor and that's it. The prop still spins freely in all R-N-F but won't start so I'm assuming it is locked in F in the lower unit. I assume there is a shift linkage or mechanism that is busted (at a minimum of course). Rocking the shifter with the cover off reveals everything up top is functioning properly.

Other than marking the rock with GPS, never letting this happen again, not running the river int he wind, etc. -

Would anyone please share any advice, experience, or insight? I really appreciate it.

 

[jimmbo]

Broken teeth on the gears

 

[sutor623]

First things first, drain the lower unit oil and see what ya got. Water? Metal chunks?

Next thing I would do is drop that gearcase and look up into the crank to make sure you didnt shear the driveshaft/crank splines. If all is well there, see if the motor spins freely without the gearcase involved. If it does, great. If not, I fear you have internal engine damage. If the motor is free push a hose up onto the water input and fire the motor up. Hopefully it will start and run well without the gear case attached, but do NOT rev the motor as it WILL take off without that driveshaft lugging the crank down.

In rare cases, when the prop strikes an object like that the internals of the engine itself can become damaged. Lets hope that's not what happened in your case, and that the gears/prop hub took all of the load off of the impact.

Next Option: Leave it be and call your insurance company. Take out a claim for a new gearcase and possibly entire engine.

I have hit many things on the river and done damage to my boats. Normally I will just fix it myself, but you can believe that if I had catastrophic damage from an incident on the water Id call a claim in quick.

 

[sfmeyer]

Thank you very much for a great response, sutor. Seems like a good order of operations and exactly what I was looking for.

First things first, drain the lower unit oil and see what ya got. Water? Metal chunks?

I'll get the gear oil drained and report back. I'm sure metal chunks is damaged gears and water is damaged seals, and obviously clean oil will be the best result?

Next thing I would do is drop that gearcase and look up into the crank to make sure you didnt shear the driveshaft/crank splines. If all is well there, see if the motor spins freely without the gearcase involved. If it does, great. If not, I fear you have internal engine damage. If the motor is free push a hose up onto the water input and fire the motor up. Hopefully it will start and run well without the gear case attached, but do NOT rev the motor as it WILL take off without that driveshaft lugging the crank down.

Ideally, the driveshaft and crank splines will look good/undamaged, the motor will start and idle without me adding any throttle, and then all of my trouble is in the lower unit where I will assess the damage from there?

Thanks, I'm just trying to get a conceptual understanding of where to go from here. I do plan to go through it myself as I want to learn from my mistakes and get an overall grasp on the mechanics of outboards. I've dealt with quite a bit on various 25-60 HP motors and I haven't had to dig into the inevitable lower unit yet.

In rare cases, when the prop strikes an object like that the internals of the engine itself can become damaged. Lets hope that's not what happened in your case, and that the gears/prop hub took all of the load off of the impact.

Next Option: Leave it be and call your insurance company. Take out a claim for a new gearcase and possibly entire engine.

I have hit many things on the river and done damage to my boats. Normally I will just fix it myself, but you can believe that if I had catastrophic damage from an incident on the water Id call a claim in quick.

Honestly, I don't insure the boat. It's a early 80's aluminum tracker hull with a 40 HP tiller. Total value did not make it something I wanted to insure, although I may look into it after this experience for the future.

 

[sutor623]

Sounds like you got a good grasp on what I was recommending for you to do.

This may be a much bigger learning experience than you realize. INSURANCE!!! Believe it or not, it is not the boat we are worried about in this case. What happens if someone slips getting onto the boat from a dock? Or your motor stalls on a windy day and you blow right into a $120,000 cigarette boat? Or way worse, you get involved in an actual collision where someone gets hurt?

My boat is worth under 10,000 clams. You know how much it is to fully insure it for property damage, personal injury etc.? $17 per month through nationwide insurance. I added it to my policy. Worth every penny.

Anyways, not to get to far off subject...... Let us know what you find.

 

[sfmeyer]

sutor, I have been looking for the silver lining in this experience and I think you just nailed it, thank you very much!! I'll report back and thank you again very much for your help and wisdom.

 

[sutor623]

Sure thing bro. Good luck!

 

[sfmeyer]

No Title

I won't be able to drop out the gearcase for a couple days but I drained the gear oil for a look.

Definite signs of metal. I don't see much water has gotten in, if any.

 

[sutor623]

Ok, the good thing is that the little shavings that you have on the drain plug are normal. That is normal wear and tear.

Now, with the water ordeal, water in oil looks milky, streaky. To me, that oil looks like it has gotten water into it. What you ought to do is catch it in a glass jar next time and let it settle 3-4 days to see if the water separates. You can also run a magnet through the old gear oil and see if you get any bigger chunks of metal.

Pull that gearcase and see if A) the driveshaft spins freely B) the engine spins freely.

 

[sfmeyer]

I drained it into a gallon ziplock and left it where it can settle. I'll share another photo in a few days when I drop the gearcase and check out the driveshaft and crank. Thank you much.

 

[sutor623]

Cool man NP

 

[sfmeyer]

I'm sorry I vanished and didn't follow up on this thread. I always try to share my resolutions to help others in return for all the help I get here. I simply overlooked it.

The forward gear was seized. The driveshaft and powerhead were in good shape.

By the time I priced out the initial repairs without guarantee, I ended up finding a used, identical 40 HP locally for only $300 and swapped lower units. Everything fired right up and I've been on the water since.

Sutor and all, thank you very much for your help.

 

[jimmbo]

A good used replacement is usually the cheapest route.

 

[sutor623]

NP buddy, glad you got it figured out. Cant beat $300 for a good bolt-on part!

 

[sfmeyer]

I just recently had the time to truly run the boat in open water. Unfortunately, I have come to find one major issue that I just can't get resolved.

Simply put, the motor runs better at 3/4 than WOT. It doesn't shut down, slow down, cavitate, or make any strange noises. The boat planes quickly, it just doesn't get up to 28-30 MPH like it did before, it tops at 22 MPH whether I have the throttle at 3/4 or full. This is a tiller model so I do not have a tachometer. I'm stuck to say I do not know my current RPM. I understand I'm going to need to figure that out if I don't get this resolved quickly.

Here is what I do know:

The motor did sit for a few months, so I rebuilt the carbs and swapped spark plugs (all looked great) as I wanted to give the motor a fresh service and start anyway. The carbs are synced and open completely. The low speed idle is well-adjusted. The motor fires up immediately, every time. It does not appear to be running hot. Compression is 105/106. The tilt/trim did not change, the fuel delivery is all the same and appears to be sound.

The only things that changed were:
1) the lower unit itself (and I don't believe that they are different gear ratios for my 40HP) and
2) the prop. The replacement outboard actually came with 2 props, and both run poorly. The better running of the two is a 13 X 11 and the second is not inscribed, although it felt like a much higher pitch.
The prop I originally had and that was trashed is a 12.5 X 13 and it ran the boat perfect. I currently have one on order, since I know boat ran so well before.

I won't be running this motor again until I get the right prop on there, and not any further if that doesn't resolve the issue, but I was wondering, am I missing something else? A thermostat? Exhaust? Is there something in the powerhead that could have gone even with my good compression?

Thank you!

 

[racerone]

When a motor comes to a " dynamic halt " ----There is the possiblity of a sheared flywheel key.------Use the top piston and see if TDC is still at the marker or pull the flywheel to inspect.

 

[sfmeyer]

Thank you, racerone.

Using the top piston, am I finding TDC by pushing the piston all the way back to the front of the motor from the plug or am I measuring that distance to divide by 2 and use a caliper to determine and set center? Appreciate the tip.

Sure hope it's just the prop.

 

[clemsonfor]

some of your speed loss is no doubt the prop. But do I think going to a 13 P prop from an 11 will get you 6mph? maybe not. But I do see 2 to 4mph gained that way.

 

[sfmeyer]

some of your speed loss is no doubt the prop. But do I think going to a 13 P prop from an 11 will get you 6mph? maybe not. But I do see 2 to 4mph gained that way.

Thanks for the thoughts. I agree and that is why I'm still searching for answers. There has to be something more than just the prop diameter and pitch. The majority of the hope that I have is in the new hub that is coming with the prop, perhaps it is spinning under that level of load.

 

[sfmeyer]

https://www.youtube.com/watch?v=kKdDdSBZieg

Watching this video and disregarding my post #17, it looks like for me to get to the TDC of the top piston, I want to stop hand turn the flywheel until the piston is at its closest point to the plug with it pulled out?