FS14LS with 9.9

[wpstarling]

Hey all,

Would a FS14LS plane with a 9.9 with 1 adult/1child and a little bit of gear (cooler, poles, etc.)? I know a lot of people are doing 15-25hp but I can get a 9.9 for a good price. Could do a GF14/16 but I've read they wouldn't plane with a 9.9.

EDIT: I tried searching but apparently I stink at it and couldn't find this question being asked previously so I apologize if it was

[VT_Jeff]

Hey all,

Would a FS14LS plane with a 9.9 with 1 adult/1child and a little bit of gear (cooler, poles, etc.)? I know a lot of people are doing 15-25hp but I can get a 9.9 for a good price. Could do a GF14/16 but I've read they wouldn't plane with a 9.9.

EDIT: I tried searching but apparently I stink at it and couldn't find this question being asked previously so I apologize if it was

Definitely maybe.

The design weight is 190lbs but as I showed here in my thread(viewtopic.php?f=12&t=64576&start=670), you'd need to waste 36% of the materials listed in the BOM in order to get to that, so not sure that is a god number to start with. I think that 290 is probably a more realistic number for a base hull weight. Add your bodies, motor and gear for an all-up weight and then TomW1 can run it through a prop calc to get you a top speed with a 9.9.

My all-up weight is around 1020(hull weight is a heavy 380) and it planes easily with a 20hp(which is actually a 15hp with a higher rpm limit) and top speed around 23-25 mph so far, I need to get the cav plate a few inches higher and may gain a few mph.

[wpstarling]

Hey all,

Would a FS14LS plane with a 9.9 with 1 adult/1child and a little bit of gear (cooler, poles, etc.)? I know a lot of people are doing 15-25hp but I can get a 9.9 for a good price. Could do a GF14/16 but I've read they wouldn't plane with a 9.9.

EDIT: I tried searching but apparently I stink at it and couldn't find this question being asked previously so I apologize if it was

Definitely maybe.

The design weight is 190lbs but as I showed here in my thread(viewtopic.php?f=12&t=64576&start=670), you'd need to waste 36% of the materials listed in the BOM in order to get to that, so not sure that is a god number to start with. I think that 290 is probably a more realistic number for a base hull weight. Add your bodies, motor and gear for an all-up weight and then TomW1 can run it through a prop calc to get you a top speed with a 9.9.

My all-up weight is around 1020(hull weight is a heavy 380) and it planes easily with a 20hp(which is actually a 15hp with a higher rpm limit) and top speed around 23-25 mph so far, I need to get the cav plate a few inches higher and may gain a few mph.

I'd think 750-800 is probably a realistic weight as of right now. obviously as my son(s) grow that weight will go up

[VT_Jeff]

I'd think 750-800 is probably a realistic weight as of right now. obviously as my son(s) grow that weight will go up

Just make sure that your weight goes down an equal amount!

[TomW1]

Wp I will run it through my calculators and see what a 9.9HP and 15 HP at 750lbs will do for you and get back to you.

Tom

[wpstarling]

Wp I will run it through my calculators and see what a 9.9HP and 15 HP at 750lbs will do for you and get back to you.

Tom

Thanks Tom.

[TomW1]

Okay wp if you total weight is the actual all in weight is actually 750 the 9.9HP will provide you a top speed of 19-22mph and a cruise of 15-17. A 15HP with a top speed of 27-29mph and a cruise of 19-22. It then kicked out a prop for the 9.9 of 8 x 9 which is what you can get if that is not on your motor. The 15HP requires a 9 x 11 prop.

Well as you see the 9.9 HP will do the job for you on this boat. It is up to you.

Regards, Tom

[wpstarling]

Okay wp if you total weight is the actual all in weight is actually 750 the 9.9HP will provide you a top speed of 19-22mph and a cruise of 15-17. A 15HP with a top speed of 27-29mph and a cruise of 19-22. It then kicked out a prop for the 9.9 of 8 x 9 which is what you can get if that is not on your motor. The 15HP requires a 9 x 11 prop.

Well as you see the 9.9 HP will do the job for you on this boat. It is up to you.

Regards, Tom

Nice! That's great news. I usually am light on tackle/stuff so it should be close, assuming I keep the epoxy at a minimum haha

[bamaguy0]

If you're up to it there's a foam version that should come in even lighter if done right. Cost will go up significantly, though. Just be sure not to build any additional features in. Stick to the plans and you should be alright.

If you do get the 9.9, see what it'd take to uprate it to 15. Usually the carbs are restricted and the timing is retarded for 9.9's since they're built for 10hp max lakes and such.

[TomW1]

bamaguy0 that is no longer the case there is a big difference in cylinder size in both the Yamaha and Mercury motors between there 9.9 and 15iHP motors. Over 100cc in the case of both. Take care guy.

Tom