Strange problem with YAM 115 4 stroke

polar2300

Cadet
Joined
Jun 10, 2004
Messages
10
I'm new to outboards and I just bought a brand new polar 23 with twin YAM 115 4 stroke 2004. 25 hours on both engines that run great, however I get this strange and infrequent problem which happened since I got it. I can be running along just fine and then a random enging starts making a low pitched nose and loses some power but no alarms go off. I am then unable to get it back to full power but if I stop completely into idle and then accelerate the engines work fine. One time I did see seaweed come out of the back. The enging had its first break in service and everything checks out fine. I have regular props not aluminum ones.<br /><br />what's going on?? any ideas?? Is it seaweed in the inakes??
 

Mercathode

Petty Officer 1st Class
Joined
Jun 8, 2004
Messages
210
Re: Strange problem with YAM 115 4 stroke

Polar were you hitting bottom with one of the motors?
 

vinney

Chief Petty Officer
Joined
Oct 29, 2002
Messages
437
Re: Strange problem with YAM 115 4 stroke

Idler puller on timing belt. Bearing in the idler pulley.
 

polar2300

Cadet
Joined
Jun 10, 2004
Messages
10
Re: Strange problem with YAM 115 4 stroke

Vinney: does that mean it needs to be retensioned?
 

vinney

Chief Petty Officer
Joined
Oct 29, 2002
Messages
437
Re: Strange problem with YAM 115 4 stroke

Replaced if the bearing is bad.
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Strange problem with YAM 115 4 stroke

hello<br /> it sounds like a fuel restriction somewhere. did the boat get rigged so that both engines draw from the same filter? you say that this problem will affect either engine at random? I doubt its mechanical due to the random nature. bearings gears and shafts dont normally fail then work then fail. mechanical fails and is finnished.<br /> try to post more info on the symptoms and rigging.<br /> good luck and keep posting
 

vinney

Chief Petty Officer
Joined
Oct 29, 2002
Messages
437
Re: Strange problem with YAM 115 4 stroke

Agree that a fuel restriction will cause a fuel pump whine. We have seen some ildler puller failure. I would run the engine with a fuel pressure gauge and watch pressure. Its hard to believe it has two bad idlers or both engines where rigged improperly.
 
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