Outboard trouble.

Bushleague · #1 09-03-2019, 04:46 PM

I have a 2004 50hp Johnson that has recently started giving me trouble at low RPM. It will idle in the yard, but out on the lake it wants to die, and when I give it throttle it bogs coming off idle and then opens up. I heard it happen while trolling, it was running fine one minuet and very suddenly it wasn't, which made me think it was a spark problem. I changed the plugs and took it for a rip, then inspected them and they look perfect.

So my next thought was a fuel line air leak, while its running there is a fair bit of air in the fuel filter, there always has been some but now it looks like a little more. However, after inspecting the lines I could find nothing, and spraying ether on the joints failed to cause a change in RPM. Ditto with pumping the primer bulb when the engine is idling.

So now I'm wondering if the spark advance could have somehow gone out, or something else? Any advice would be welcome, thanks.

Positrac · #2 09-03-2019, 05:24 PM

Spray some Seafoam into the car until it dies. Let it sit 15 minutes then start it up. I’d also run some Seafoam in the tank. There’s probably just some crud in the carb. There’s 2 kinds of Seafoam at Canadian Tire, 1 a spray and 1 a liquid for the tank.

I’ve had it fix all kinds of issues.

Drewski Canuck · #3 09-03-2019, 08:45 PM

When you say "idle in the yard" are you running on a garden hose and muffs?
When you run on the lake, is the hood on?

If so, I bet you have an exhaust leak on the leg. On the driveway no restriction. On the lake, backpressure on the exhaust. Bet it runs fine on wot because the drag "pulls" the exhaust out.

At the lake take the hood off, start it and see if it now idles. If so then its an exhaust leak and you are drawing back in exhaust into the air intake under the sealed motor hood.

Drewski

58thecat · #4 09-08-2019, 07:43 AM

Check your water pump impeller....at idle not enough water getting through and she will over heat and shut off and at speed above idle enough water gets through to keep her happy.....went through this des nagging process just to find exactly that only one blade left on the impeller of the pump....it's a 20 minute job to do.

Good luck.

Drewski Canuck · #5 09-09-2019, 10:29 AM

58thecat,

You make a fair point. On the driveway with muffs and a garden hose, there is water pressure so impeller is not a problem.

But at the lake, we REALLY need to see a video of the motor running to understand what is happening here.

If the motor runs 10 - 15 minutes and then acts up when it warms up, ...

then yes, it is overheating. On Start up if the problem is immediate when submerged at the lake without pressure, then look at the exhaust issue.

Sad part about Alberta is we really only have 12 - 16 weekends to use a boat, and if something goes wrong, the shops are all swamped with work and in a worst case scenario, by the time its fixed you might as well winterize the motor.

Drewski

oilngas · #6 09-09-2019, 11:31 AM

drewski; I don't know where u are at, but if Calgary, then Auto Marine (talk to Sue or Brian) has gone out of their way to help me when I'm in a pickle.

barbless · #7 09-09-2019, 01:52 PM

Quote:

Originally Posted by oilngas

drewski; I don't know where u are at, but if Calgary, then Auto Marine (talk to Sue or Brian) has gone out of their way to help me when I'm in a pickle.

X2 with Auto Marine. They are awesome to deal with and talk to. They have helped me lots over the years. I would not take my 150 2 stroke or my 8 HP kicker (both Yammy's) anywhere else when service is needed that I can't do. Brian actually offered to help me last year after hours on a Sunday to re-wire my boat from key to engine.