97 225 mercury blowing the prop hub

[bonitoman]

My friends 97 mercury 225 has blown 3 hubs fishing in deep water in the past 5 trips. What would cause this if he is not hitting anything. Fish on the east coast of florida in the ocean. The prop is a vengance. Boat has 700 hours with the same prop from day one. Never had any problem before with the engine or prop until this summer.

 

[WillyBWright]

Re: 97 225 mercury blowing the prop hub

I seem to remember something about water from the trim tab cavity being directed to the prop hub to assist in cooling the hub. If the trim tab is missing, that would prevent that water from getting there. It could also be a weak water pump putting out enough to cool the motor, but not cool the exhaust adequately. Whatever the case, it sounds like the prop hub is getting too hot from exhaust gasses.

 

[Perfidiajoe]

Re: 97 225 mercury blowing the prop hub

3 hubs in 5 trips is a lot, if the thrust washer is not missing or if nothing is binding up the prop,(should spin free when not in gear), check to see if anything is cracked in the hub, not just the rubber. If this is the same prop just rehubbed try a different prop, & make sure the prop shaft isn't bent. good Luck, Joe

 

[BW23]

Re: 97 225 mercury blowing the prop hub

Mercury Marine Service Bulletin 96-20 <br />(Updated 08/10/98, originally issued in 1996) <br />In response to reports of burned propeller hubs and <br />bearing carrier seal burn-out on 1997 3.0L outboard <br />engines, Mercury Marine issued a service bulletin <br />noting that engines operating in the 2000 rpm range <br />may not receive sufficient water supply to the exhaust <br />system, resulting in excessive exhaust <br />temperatures. It was found that the poppet/relief <br />valve spring has incorrect tension, which doesn't <br />allow poppet/relief valve to open in this rpm range. <br />When lower unit is removed, the rubber filler block <br />will have a burnt appearance. <br /><br />Involved are 1997 Mercury 225hp & 250hp 3.0L OBs <br />& 1997 Mercury 225hp Seapro / Marathon 3.0L <br />engines, s/nos OG438999 -- OG518681 <br />Mercury replaced old parts w/ poppet/relief valve <br />spring p/n 24-854478 and new gaskets (2) p/n <br />27-88907. Engines reworked at the factory are <br />identified w/ an "X" stamped on the engine carton <br />near the serial number. Dealers are instructed to <br />paint a white dot on the poppet/relief valve cover. <br /><br />According to the bulletin, failures were covered under <br />warranty if they occurred within 1 yr warranty period. <br />Mercury assigned this condition Failure Code: 618 <br />87. Prop hub failure or lower unit failure due to <br />bearing carrier seal burn because of faulty spring is <br />also covered.<br /><br /><br /> http://my.boatus.com/forum/forum_posts.asp?TID=47566&KW=BW23

 

[KCLOST]

Re: 97 225 mercury blowing the prop hub

Very Nice BW.....