Offshoreonly.com

Offshoreonly.com (https://www.offshoreonly.com/forums/)
-   General Boating Discussion (https://www.offshoreonly.com/forums/general-boating-discussion-51/)
-   -   Fountain 38 lightning topspeed (https://www.offshoreonly.com/forums/general-boating-discussion/355282-fountain-38-lightning-topspeed.html)

Bjornj 07-12-2018 02:18 PM
Fountain 38 lightning topspeed
 
Hello.
New owner to a 2005 38 lightning with 525 efi bravo Xr semi stagered.
Im not pleased with the topspeed. I get 75mph 79mph one time. Testreport says 93mph.
I get 5000rpm on Stb engine and 5300 on port.
Drive setting 4or 5 on indicators.
I have bravo 32p. Props.

What at are your ideas? Anyone with same boat? Top speed?

Looking forward to hear from you.

VoodooRob 07-12-2018 02:47 PM
Lots of variables. Hours on engines? Compression and leak down test? Pulled valve covers looking for broken springs? When were top ends done? What props does your test report say the boat should have, brand and 4 or 5 blade? Props spinning in? Props in very good condition, have they been measured and checked for true? Thats just a start for ideas.

dcb 07-12-2018 03:24 PM
You may also want to post this question in the Fountain owners forum. Lots of knowledgeable people there.

Jupiter Sunsation 07-12-2018 03:37 PM
Originally Posted by Bjornj (Post 4637278)
New owner to a 2005 38 lightning with 525 efi bravo Xr semi stagered.
Im not pleased with the topspeed. I get 75mph 79mph one time. Testreport says 93mph.
I get 5000rpm on Stb engine and 5300 on port.
Drive setting 4or 5 on indicators.
I have bravo 32p. Props.

What at are your ideas? Anyone with same boat? Top speed?


You need to bring the boat to the magical Pamlico river, home of the 5 mph current and favorable winds! Then hire a 100 lb leprechaun with blessed hands to throttle that 35 ft beast to its top speed! Be sure to be environmentally friendly and never have more than 8.3 gallons of fuel aboard and point the beak down river! May the GPS genie be with you! :D

Bjornj 07-12-2018 03:57 PM
Originally Posted by VoodooRob (Post 4637284)
Lots of variables. Hours on engines? Compression and leak down test? Pulled valve covers looking for broken springs? When were top ends done? What props does your test report say the boat should have, brand and 4 or 5 blade? Props spinning in? Props in very good condition, have they been measured and checked for true? Thats just a start for ideas.
150hours. No leak down or compression test yet.
Valvesprings looks good.
No topendsdone.
Test report uses same props as I have 4 blade bravo 32. Looks good. Thinking of borrow another kit to try with.

Wildman_grafix 07-12-2018 04:00 PM
Originally Posted by Jupiter Sunsation (Post 4637297)
You need to bring the boat to the magical Pamlico river, home of the 5 mph current and favorable winds! Then hire a 100 lb leprechaun with blessed hands to throttle that 35 ft beast to its top speed! Be sure to be environmentally friendly and never have more than 8.3 gallons of fuel aboard and point the beak down river! May the GPS genie be with you! :D
My report has 84 on it, I normally can hit 85, lots of time 82-83 no problem full fuel load easy.

My buddy just got a 35 EX with 525's and report has it at 88, there is issues with props on his but so far we have seen 87 with him, me, and our wives, lots of fuel, junk they take and Florida heat (two weeks ago).

Those reports are really pretty nice, they show how the boat was ran and set up to hit the posted speed. I don't remember seeing other manufactures doing that but maybe they did.
All that said you defiantly need to start looking at things.
Your numbers show prop slip 25% - 28%. Something not right.

Wildman_grafix 07-12-2018 04:02 PM
Originally Posted by Bjornj (Post 4637302)


150hours. No leak down or compression test yet.
Valvesprings looks good.
No topendsdone.
Test report uses same props as I have 4 blade bravo 32. Looks good. Thinking of borrow another kit to try with.
The 35 I said of my friends boat someone had cut the diameter down on them. Don't know why, but take one step at a time till you find it.

Bjornj 07-12-2018 04:13 PM
How do you trim your outdrives? Indicators at 5?
Boat is out of water for a few days. Now cleaning and changing a leaking Powertrim hose. Then we gonna keep on testing. Poker run in Sweden next weekend😃

Bjornj 07-12-2018 04:14 PM
Is it a 38 you have also?

Marginmn 07-12-2018 05:41 PM
The semi-staggered 38 should run over 90 with ease. You have either some very tired mills or some hook in your hull - or both.

Griff 07-13-2018 12:39 AM
I would be concerned about the 300 rpm difference

Knot 4 Me 07-13-2018 06:39 AM
Originally Posted by Griff (Post 4637393)
I would be concerned about the 300 rpm difference
Agree.

Dean Ferry 07-13-2018 07:33 AM
Originally Posted by Wildman_grafix (Post 4637305)
My report has 84 on it, I normally can hit 85, lots of time 82-83 no problem full fuel load easy.

My buddy just got a 35 EX with 525's and report has it at 88, there is issues with props on his but so far we have seen 87 with him, me, and our wives, lots of fuel, junk they take and Florida heat (two weeks ago).

Those reports are really pretty nice, they show how the boat was ran and set up to hit the posted speed. I don't remember seeing other manufactures doing that but maybe they did.
All that said you defiantly need to start looking at things.
Your numbers show prop slip 25% - 28%. Something not right.
WG,
Hustler does test reports, got 1 each for the Talon (88mph with 496 HO, which is not in the boat anymore), and 388, (90mph).
Thanks,
Dean

Wildman_grafix 07-13-2018 07:58 AM
Originally Posted by Dean Ferry (Post 4637417)
WG,
Hustler does test reports, got 1 each for the Talon (88mph with 496 HO, which is not in the boat anymore), and 388, (90mph).
Thanks,
Dean
Cool Dean and yes I think the little Hustler does just a bit more then that now! LOL

You going to the pirate party Saturday?

Dean Ferry 07-13-2018 08:15 AM
[QUOTE=Wildman_grafix;4637425]Cool Dean and yes I think the little Hustler does just a bit more then that now! LOL

You going to the pirate party Saturday?[/QUOTE
WG,
yes, if I don't have to work....

payuppsucker 07-13-2018 10:15 AM
Your leaking trim hose may be the problem with your RPM split, (drive tucking in due to leaking hose).
that would also scrub off some speed.

RaggedEdge 07-14-2018 07:05 PM
Originally Posted by Marginmn (Post 4637329)
The semi-staggered 38 should run over 90 with ease. You have either some very tired mills or some hook in your hull - or both.
Agreed, reality is a staggered 38 should run low 90's pretty easily. Have run side by side with a couple in some local runs at 92 - 93. Your numbers are off, something is wrong. All the BS over the years about the Fountain factory reports are just that. If you know how to run the boat you should be able to run the number they show on the report.

BenPerfected 07-15-2018 01:31 PM
Originally Posted by Bjornj (Post 4637278)
Hello.
New owner to a 2005 38 lightning with 525 efi bravo Xr semi stagered.
Im not pleased with the topspeed. I get 75mph 79mph one time. Testreport says 93mph.
I get 5000rpm on Stb engine and 5300 on port.
Drive setting 4or 5 on indicators.
I have bravo 32p. Props.

What at are your ideas? Anyone with same boat? Top speed?

Looking forward to hear from you.
My thought is to now send your props to a prop shop and see what you have. Also check prop shaft height from the bottom of the boat to confirm they are equal.

Bjornj 07-15-2018 02:05 PM
Yes I’m gona send my props to a propshop. (Talked to them yesterday). Also want to confirm I have the correct gear ratio.


All times are GMT -5. The time now is 02:25 AM.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.