115 yamaha outboard main bearing trouble?

dpdowling

Recruit
Joined
Jun 14, 2003
Messages
1
I have a 115 yamaha v4 that was nebuilt just last year. it has about 100 hours on it. I run a 50/1 mix of oil to gas in my main tank on top of it being fuel injected as I also use the kicker motor run on the same tank an to give added lube to the engine. I was cruising at about 2500 rpm when I heard the motor suddenly start knocking. I shut it down and limped back in on the kicker. the motor starts and runs but knocks and the fly wheel lifts about 3/8" when it cranks over. I can also lift the fly wheel the same by hand. I think this could be a top main bearing. My question is do I have to pull the whole powerhead and seperate the head and crankcase to get at the bearing or is there a way I can remove the fly wheel, stator, and remove and replace the bearing. would a bad bearing allow the flywheel to lift? would it also cause any damage interally? <br /><br />Thanks,<br /><br />dpdowling
 

Capt Ken

Commander
Joined
Jul 30, 2002
Messages
2,269
Re: 115 yamaha outboard main bearing trouble?

Not the upper bearing that holds the crank down. It's the lower bearing that is fixed on the crankshaft and holds it in place via a retaining clip. If the flywheel don't move from side to side, the upper bearing is probably OK. The knock is something else and you're probably looking at a teardown.
 
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