boater1234
Master Chief Petty Officer
- Joined
- Jan 6, 2010
- Messages
- 869
I just went to my marina and got my 9.9hp 2stroke yamaha upgraded to a 15hp for $180[$75]for the part and $85 for labor +shop supplies and tax of course.I couldn't belive my eyes on what seperates an exta 5hp or more.A 9.9 makes its power at 5000rpm as well as the 15hp makes it at 5000rpm so it's rated up to 5500rpm so it may push a few more horses i would think[please correct me if i'm wrong here.]I would think it may hit 16 to 17hp with an extra 500rpm to spare.
The [only thing] seperating it was the exact same reed valve setup,[in other words a 9.9 has limited air flow as with a 15hp reed valve which looks the same has more clearance[wide open valve] for air flow,no restrictor plate on the newer ones anymore as the older ones did.It amazes me that a $75 part can make so much more power and top end.I could feel the difference in hole shot and the top end was close to 5mph faster according to my gps.I mean it wasn't like we were blazing but for under $200 i think it was well worth it.I was at 18mph with the 9.9 loaded down,me,the wife,child 150qt cooler filled up with ice,food and drinks,3/4 plywood floor livewell full and all the gear.We were almost hitting 23mph with the stock prop.I have a 10.5 pitch coming so that should give me a few mph more.There is a 9x9 on there now.I can only imagine what it may hit with just me and gear,maybe 26 to 28mph who knows.My boat it wider and very light at only 200lbs so that helps.
I just wanted to throw my experience out here if someone has been wanting to do it but doesn't think it's worth the money or won't do much as far as power or top end.I had the marina i bought the motor from convince me in the beginning it wasn't worth the money as the performance would be almost the same,but i have to tell ya i'm glad i did it.I know it's a true 15 now and has that little extra kick to it when needed plus a close to 5mph increase.Well maybe this will help someone out here one day.
The [only thing] seperating it was the exact same reed valve setup,[in other words a 9.9 has limited air flow as with a 15hp reed valve which looks the same has more clearance[wide open valve] for air flow,no restrictor plate on the newer ones anymore as the older ones did.It amazes me that a $75 part can make so much more power and top end.I could feel the difference in hole shot and the top end was close to 5mph faster according to my gps.I mean it wasn't like we were blazing but for under $200 i think it was well worth it.I was at 18mph with the 9.9 loaded down,me,the wife,child 150qt cooler filled up with ice,food and drinks,3/4 plywood floor livewell full and all the gear.We were almost hitting 23mph with the stock prop.I have a 10.5 pitch coming so that should give me a few mph more.There is a 9x9 on there now.I can only imagine what it may hit with just me and gear,maybe 26 to 28mph who knows.My boat it wider and very light at only 200lbs so that helps.
I just wanted to throw my experience out here if someone has been wanting to do it but doesn't think it's worth the money or won't do much as far as power or top end.I had the marina i bought the motor from convince me in the beginning it wasn't worth the money as the performance would be almost the same,but i have to tell ya i'm glad i did it.I know it's a true 15 now and has that little extra kick to it when needed plus a close to 5mph increase.Well maybe this will help someone out here one day.