Engine makes loud noise/revs...potential weeds?

26stixx

Cadet
Joined
Jun 27, 2017
Messages
8
Hi,
I have a 90 HP yamaha on a 20' pontoon. I was cruising a river the other day then my engine slowed abruptly and the engine revved up quickly. I backed off the throttle then continued slowly.
I continued along my way then it did it again a few minutes later.
Any ideas on what is happening? Could it have been a weed clump or something? It's lake Scugog.....very shallow and weedy.

Thanks
 

26stixx

Cadet
Joined
Jun 27, 2017
Messages
8
I did take the time to stop, then put it in reverse to get the weeds off if there were any. I then resumed driving.
-If it was weeds, would it rev like that? or just bog down?
 

HotTommy

Lieutenant Junior Grade
Joined
Mar 15, 2013
Messages
1,025
My guess is that the obstruction caused it to bog until the prop began to slip on the hub. If that is the case, you'll want a new hub. You can check by putting a waterproof alignment mark on the prop and hub. If it happens again, check to see if they are still aligned. If not, it slipped.
 

5150abf

Vice Admiral
Joined
Aug 12, 2007
Messages
5,808
Yes, a big clump of weeds will cause you engine to rev up without going anywhere.
the weeds disturb the water flow enough that the prop doesn't have any water to grab so it spins freely.

I have the same issue here with leaves in the fall, they build up on the front of the bullet and you need to stop and let them fall off before continuing.

I like Tommys idea, it will show it is slipping or alleviate that option, if it is a shallow weedy lake I am going to say it was build up but better to mark it and know for sure.
 
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