Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: yamaha 25 hp 4 stroke problems

Posted by Wpj2142 on 07/08/10 - 9:48 AM
#1

I have a 1987 13' whaler and recently purchased a new 25 hp yamaha 4 stroke. Motor runs fine on the hose but when I have tried to run it in the water it appears to ingest water in the exhaust and shuts off. Yamaha claims that the motor is not appropriate for this application and will not help. Yamaha claims its 4 strokes are just too heavy for this type of boat. When I come off plane or try to go in reverse, it sputters and dies. Takes ten minutes or so to restart. Has anyone else had this problem?

Posted by number9 on 07/09/10 - 1:38 AM
#2

What year and model is the F25? It may just need to be raised to get the "idle hole" higher. Shaft length on those is actually 21.7" and should be raised 2.25" or more to get better performance anyway. If it has a clamp mounting bracket it will be more difficult and require some type of transom/jack plate.

I've never heard of that problem but can imagine a tiller steer F25 and weight of fuel/battery/operator aft would make it sit low.

Posted by Wpj2142 on 07/09/10 - 7:14 AM
#3

It is a 2009 F25LA with controls. The dealer has moved it up as high as it can go, according to him. Dealer is now offering to switch it for a 20 hp.

Posted by Jkcam on 07/10/10 - 5:36 AM
#4

Don't count me as any authority, but I believe that the weight of the old 40hp 2strokes, (Evinrude, Johnson, Merc., etc.) which were very standard on a 13 is about the same as a Yamaha F25. If that is the case, and you have the correct shaft length, there may be other issues going on. Was the boat trailered or left in the H2O?

Posted by mainewhaler13 on 08/03/10 - 1:27 PM
#5

I have a 1964 13 whaler and just hung a 2006 Yamaha F25, tiller with electric start (156lbs). Runs like a top and no problem with the pee hole taking water even when coming off plane. I would increase the idle as someone metioned.

Edited by mainewhaler13 on 08/03/10 - 1:27 PM

Posted by Binkie on 08/03/10 - 3:28 PM
#6

Sounds like the dealer is playing you. Buy a universal tiller extension, move the rear seat as far forward as possible, mount it on top of the seat clamps and place the battery and fuel tank under the seat. You will see a big difference in rid-ability and performance. All 13 foot Whalers are unbalanced and their CG is too far aft. It is inherent in the design. Ray Hunt screwed up on this design, and tried to fix it by putting a hook on the bottom at the transom, that didn`t really work anyway. If the engine still appears to drown coming off plane after making these changes the problem lies elsewhere.