Strange Gear Noises

General Boats and Motors
1

Hey guys. On our run out to catch some Dolphin with everyone else and their brother on Saturday, I had a set of strange occurrences with my motor and throttle.

The short story is that running along at about 5,500 RPM (30 knots or so), the motor would straight up die, accompanied with a disconnecting gear sound from the throttle quadrant. Seemed like it was popping out of gear. It was the same noise that happens when you don’t quite put the motor in gear and it “grinds” for a few clicks. You know what I mean? The ratcheting sound happened exactly when the motor would die. Once or twice I was able to grab the throttle and pull it back out of gear, and the motor did not quit. It did this once on the way out, about 45 miles into the run out. The motor started right back up, and ran through the whole time trolling, and all the way back past Ft. Sumter. Once in the harbor, it did this repeatedly. It would die with a ratcheting sound. After about 4 or 5 times doing this, it finally would not start back up. My son noticed that the primer bulb was completely flat at this point. I worked the bulb, and eventually got it to inflate and fill up with gas. I primed the motor back up, and it started right up and ran the rest of the way to Remley’s without dying or giving me that ratcheting sound.

Has anyone every heard of, experienced, or seen anything like this? I don’t know a lot about outboards, but it seems to me that if the motor is slipping out of gear, there might be a fail safe for the motor to quit if this happens uncommanded, making me think that I have a gear problem, not a motor problem, because the motor ran great all day, and started back up every time, the first time, except that last time.

Thanks for reading this, and offering whatever help you can.

2

gear noise when shutting down while stll in gear is normal, yes, its like a ratchet. now figutr out whats causing you to shut down

3

I recently read a post from someone who was having the same problem and opening the gas cap would remedy the problem. Someone said it was a vent filter issue or something. I don’t remember if the thread was on here or on THT He said the same thing (primer bulb sucked flat) said when he opened the cap socking noise and problem went away.

2005 Sea Hunt 212 Triton
“Head East”

4

@spareparts Like I said, I’m not an outboard mechanic. I only know what I’ve learned from working on it myself when I could. With all the motor issues I’ve had over the past two years, I never had the gear noise when it quit on me. When it was constantly dying in the harbor on the way back in I would run it at 5500 RPM, it would die, then I would go at like 3,000 RPM to see if that helped, and I got the same result. It would die with a loud gear noise. All this to say, I’ve had a lot of circumstances where my motor has quit on me these past two years and that has lead to a lot of work on it. I’ve worked on it and had it worked on. But this is the first time it sounded like it was slipping half out of gear every time it died. I hear what you are saying but I don’t ever recall this combo of noise and failure before.

@Head East We did loosen and take off the cap. That did nothing to help with the bulb. Meaning when I took the gas cap off, the bulb remained flat. We let it sit for about a minute or so to see what would happen.

5

Was this happening at a regular interval on the way in? Could be starving for fuel while running and then once it shuts down it has a chance to get some more fuel run for a bit then die and repeat. The bulbs can go bad on the fuel line. Sounds like a fuel issue.

6

Hey guys. So as I’m understanding all you smart folks, the engine dies and the resulting momentum of the boat keeps the prop turning, but now in reverse, giving me the sound. So the sound is the result of the engine dying.

@fishcrazy It happened once about 45 miles out, headed offshore. The motor started right back up and ran the rest of the way through 5 hours of trolling, and a two hour ride back in. It happened again in the harbor, and started right back up. I ran a few hundred feet, and it died again. This is when the “repeated” part happened because I couldn’t get it the boat moving for more than a few hundred feet. The last time it happened it wouldn’t restart. My son noticed the brand new bulb (like two months old) was flat. We opened the gas tank cap and that did nothing. I massaged the bulb and got it to refill. I primed the motor and we ran the three miles or so back to Remley’s with no issues. We sat for a while waiting for our spot to dock, the motor kept running at idle while I waited my turn to get the trailer down, and ran until I shut it off.

I’m thinking that an intermittent fuel line blockage might be my problem. Does this check with everyone else?

7

if you were to shift the motor to neutral as it was dying, the sound would go away
the water is turning the prop faster than the motor is, and it is indeed “ratcheting” like spare parts said.

if the bulb is going flat, either the fuel pump is dying or you have an obstruction between the bulb and the gas

www.teamcharlestonmarine.com
www.joinrfa.org
IF I RESPOND IN ALL CAPS, ITS NOT ON PURPOSE, AND I AM NOT YELLING

8

I guess then this leads to my next question . . . . . how does one find an obstruction, especially if it is in the gas tank? I have gently blown some air into the overboard vent tube and the pressure came right back out the vent, nice and smooth. When I prime, the first filter with the clear bowl fills with gas quickly after each pump. So I’m pretty sure I’m good between the bulb and the motor. The motor ran like a champ for so long, and then for a good amount of time after the last restart, I’m having trouble thinking it’s in the motor itself. The three low pressure pumps are all brand new (like less than a year old), and I thoroughly went through the fuel system last fall chasing down other problems and cleaned out all the filters, adjusted the fuel/oil mixtures, checked all the pumps, etc. For my money, the blockage (if there is one) is in the tank at the pick up, or between the bulb and the tank. What is a good way to check these lines and areas?

9

Cheap fix, replace the bulb. While you have it apart, blow some air (not too much pressure) back into the tank from where the bulb connects to the hose. Also check for kinks in the line from the bulb back to the tank.

'06 Mckee Craft
184 Marathon
DF140 Suzuki

10

The bulb is less than three months old. It’s brand new. However, I’ve not introduced any pressure from the bulb end of the fuel line into the tank.

What I’m wondering is though, putting pressure from the two lines (the vent and the line to the bulb) will knock whatever obstruction is there into the tank. Leaving me with an obstruction in the tank. What then? How do I check to see if I have something floating in the tank? From what I know of large airplanes, a large fuel tank can get sludge, and all sorts of great things in the tank after a while. How do I check my fuel tank for such things?

Thanks for all the help here guys. You are all the reason I always come here to ask questions. All these years, y’all have taught me so much.

11

Could the inner jacket of your fuel line be collapsing?
I’ve seen ethanol cause the inner jacket to separate from the rest of the fuel line and cause the fuel flow to stop.

218WA Sailfish
200 Verado
The "Penn"sion Plan

12

You are definitely right about sludge and other “stuff”. I have seen big chunks of what appeared to be rust floating around in the bottom of a tank before. There should be a way to get to the fuel tank sending unit. It would be wise to run the tank close to empty as possible and then pull the sending unit. If you do that, be careful of anything that could possibly cause a spark, because the last thing you need is a burned up boat. You can usually get a good look into the tank from the sending unit. Of you find anything, just pump it out and then try to wipe as much of the residue out with some clean rags taped to a wooden dowel.

Hopefully it’s not that serious and it’s just a kinked hose or something easy to fix. In all reality it could be a number of issues, but I’d bet the problem is in the line.

'06 Mckee Craft
184 Marathon
DF140 Suzuki

13

This sounds suspiciously like a partially clogged tank vent; especially if the primer bulb is getting sucked flat. Find your vent line remove it. Clean it out even if you can blow through it. Maybe some insect or critter took up residence.

2013 Ranger Z21 Intracoastal 250 hp Yamaha VMAX SHO

14

If it were the vent opening up the gas cap would have corrected the problem. The problem is somewhere between the primer ball and the gas tank. Either clogged separator/filter, bad or blocked fuel line or fitting.

Wellcraft V-20 sportfish with a 200 Evinrude

15

WEDONT TRY TO FIND THE OBSTRUCTION, IF THERE IS ANY ISSUE, WE JUST REPLACE THE PICK UP TUBE, THE ANTI-SIPHON VALVE, THE FUEL LINE AND THE PRIMER BULB.
TO CHECK FOR AN OBSTRUCTION, WE USE A HIGH CAPACITY VACUUM FUEL PUMP AND A VACUUM GAUGE

www.teamcharlestonmarine.com
www.joinrfa.org
IF I RESPOND IN ALL CAPS, ITS NOT ON PURPOSE, AND I AM NOT YELLING

16

WOW! This is all amazing info everyone. Thanks so much. I’ll get on this and report back.

17

Not sure if this is even close but a buddy of mine had something similar happen to his boat. He had to replace a section of the gas line between the primer and the gas tank. The liner inside the tube become loose and was preventing gas from reaching the outboard. Hope you figure it out!

18

Alright gang. Here’s what I did today.

I pulled the fuel sending line as far out of the tank as I could. Whatever filter elements are on the end of the line in the tank are too big to pull completely through the hole in the tank. At least, the resistance given was too much for me to be comfortable to just yank it out of there. The line I could see looked clean and free of debris.

I removed, inspected, and even found a way to test my anti-siphon valve. All there checked out good.

The big rubber hose that goes from the sending line to the fitting in my hull looked clean, in piece, and in good health. It is a solid rubber hose, with a fabric reinforced core, if you get my meaning. No layering to collapse.

The more rigid fuel lines that run from the fitting to the main fuel filter and the line from the fuel filter to the bulb checked out as well. These lines have an opaque, grey outer layer, and what looks like a clear, or clear-tan inner layer. These lines are not completely rigid, but not very flexible either. I can not tell if there is anything wrong inside these lines from what I saw.

I disconnected the line from the motor, and primed the bulb. It shot fuel in a perfect stream. The bulb took a second or two to reinflate between pumps, but it did inflate. I hooked it back up to the motor, and it only took two pumps before the bulb became rigid and the line full.

I removed the vent line, and checked the vent “valve” that goes through the hull of the boat. All free of debris. Again, I gently gave some pressure to the vent line, without the valve (so directly to the hose itself) and the rush of air out of the line was instant and strong. So no blockage there.

I opened the gas cap, introduced air in the vent hose, and air came out of the gas fill line, where the gas cap would be. I closed the gas cap, and tried it again and the air came back out of the vent line.

To recap, my main filter is about three months old. The bulb is about three months old.

Am I missing anythi

19

replace all that fuel line, especially that grey hose with the inner liner. You didn’t say, but if your primer bulb is anything other than OEM(Yamaha, Merc, Bomb, etc…) throw it in teh trash and get one from an oem

20

This is where I show my ignorance . . . . Is it that imperative to have an OEM bulb? No, my new one is not Yamaha OEM.