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Help 91 fountain 38sc prop /rpm

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Help 91 fountain 38sc prop /rpm

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Old 07-08-2012, 05:49 PM
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Default Help 91 fountain 38sc prop /rpm

HELP , I am new to this forum /I just picked this up everything seems sound but the rpm and speed feels off. Please give me your inpute , should I consider changing props?


(24) prop
(power)twin staggered 502 stock
3000 (max rpm)
max speed 55
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Old 07-08-2012, 09:22 PM
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Somethings wrong, but I do not think it is props. Rpm should be around 5000. Speed should be around 65, at least. I would try a tune up first. Bill
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Old 07-09-2012, 02:17 PM
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engines are sound, if it was a power issue i believe each motor would have a different personality, Both are identical and run great, just max out at 3000
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Old 07-09-2012, 02:55 PM
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john, looks like the boat is propped for mid range not top speed. if top end is what your looking for try a 23 pitch 3 blade and you will see 65 mph and 5300 rpm. its all what your looking to do.
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Old 07-09-2012, 07:02 PM
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WOW !!! I must really be dumb.
My guess would be that the stock 502s in a staggered setup should easily hit 5000 rpm with a pair of 24's in a Fountain hull.
I thought that even stock they should be 400hp and should pull the pitch of your current props.
I was also thinking tune up like Bill did.
If your motors are running great and all you can pull is 3000 rpm I'd have to agree with U-cat, drop a blade and a number on the pitch.

John,
Welcome to the board, I'm still a newbie here too but I've learned a bunch from the membership.
Congrats on your boat, I almost bought a 38SC but couldn't get the seller on the same page as to the boats realworld value. He was stuck on the value of the Mfg's reputation and wouldn't come down off his cloud
I really wanted it because I felt it would go at least 10mph faster than the Baja with equal power.
WAY TO GO, it's a nice one with potential for some good speed from a performance cruiser.

See ya,
Kelly
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Old 07-09-2012, 07:13 PM
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Something is wrong. Throttle cable throw??
You should be able to pull those props to the mid/upper 4000's.

Brett
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Old 07-10-2012, 07:45 AM
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Im going to find some 23 props and test them out. I have 4 blade now, should I switch to 3 blade when I go to 23?
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Old 07-10-2012, 10:06 AM
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Originally Posted by bbladesprops
Something is wrong. Throttle cable throw??
You should be able to pull those props to the mid/upper 4000's.

Brett
I agree. Dropping to 23 is not going to get you the spec max RPM for your 502 carbs which is >>

4800-5000 WOT

Cable adjustment is worth checking out first.

I had the same motors in my 93 35 Lightning.
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