Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Steve Helling
 
Posts: n/a
Default Slow Cruising Speed Question

I recently did a sea trial on a boat I'm thinking about buying, a 1990
Thompson 288 Adventurer flybridge cruiser with twin 350 mercruiser inboards.
I was disappointed to find that at 3200 RPM, trimmed for max speed, it could
only make 13-14 knots, as indicated by GPS, and at WOT, around 4800 rpm, it
topped out at about 24. This was in glass-smooth protected waters with
little wind. The engines seemed to be running fine, but this seems a rather
slow boat. It's my understanding that much over 3200 rpm the 4bbl carbs
open up and send fuel consumption through the roof. Any thoughts or advice
for this beginner?

Steve



  #2   Report Post  
DaveH
 
Posts: n/a
Default Slow Cruising Speed Question

Maybe the thing is just propped way too much. Regardless, unless the owner
can get it performing decently, stay away!

"Steve Helling" wrote in message
...
I recently did a sea trial on a boat I'm thinking about buying, a 1990
Thompson 288 Adventurer flybridge cruiser with twin 350 mercruiser

inboards.
I was disappointed to find that at 3200 RPM, trimmed for max speed, it

could
only make 13-14 knots, as indicated by GPS, and at WOT, around 4800 rpm,

it
topped out at about 24. This was in glass-smooth protected waters with
little wind. The engines seemed to be running fine, but this seems a

rather
slow boat. It's my understanding that much over 3200 rpm the 4bbl carbs
open up and send fuel consumption through the roof. Any thoughts or

advice
for this beginner?

Steve





  #3   Report Post  
Go Fig
 
Posts: n/a
Default Slow Cruising Speed Question

In article ,
"Steve Helling" wrote:

I recently did a sea trial on a boat I'm thinking about buying, a 1990
Thompson 288 Adventurer flybridge cruiser with twin 350 mercruiser inboards.
I was disappointed to find that at 3200 RPM, trimmed for max speed, it could
only make 13-14 knots, as indicated by GPS, and at WOT, around 4800 rpm, it
topped out at about 24. This was in glass-smooth protected waters with
little wind. The engines seemed to be running fine, but this seems a rather
slow boat. It's my understanding that much over 3200 rpm the 4bbl carbs
open up and send fuel consumption through the roof. Any thoughts or advice
for this beginner?

Steve




When was the bottom last cleaned ?

Something is wrong here... find out what it is.

jay
Thu, Sep 18, 2003


--

Legend insists that as he finished his abject...
Galileo muttered under his breath: "Nevertheless, it does move."
  #4   Report Post  
Steve Helling
 
Posts: n/a
Default Slow Cruising Speed Question

The bottom is clean, and it is kept in dry storage. I don't trust the
tachs, considering the stbd tach reads 4000 when the port tach reads 3200.
They may both be reading high. I'm also considering whether it could be a
prop, engine, or weight issue.



"Go Fig" wrote in message
...
In article ,
"Steve Helling" wrote:

I recently did a sea trial on a boat I'm thinking about buying, a 1990
Thompson 288 Adventurer flybridge cruiser with twin 350 mercruiser

inboards.
I was disappointed to find that at 3200 RPM, trimmed for max speed, it

could
only make 13-14 knots, as indicated by GPS, and at WOT, around 4800 rpm,

it
topped out at about 24. This was in glass-smooth protected waters with
little wind. The engines seemed to be running fine, but this seems a

rather
slow boat. It's my understanding that much over 3200 rpm the 4bbl carbs
open up and send fuel consumption through the roof. Any thoughts or

advice
for this beginner?

Steve




When was the bottom last cleaned ?

Something is wrong here... find out what it is.

jay
Thu, Sep 18, 2003


--

Legend insists that as he finished his abject...
Galileo muttered under his breath: "Nevertheless, it does move."



Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is Off
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Motor question - Prime/Idle speed Small Business General 0 July 8th 04 11:06 PM
Props - RPM's and Cruising Speed [email protected] General 14 June 1st 04 04:11 AM
Slow Cruising Speed Question Steve Helling General 10 September 26th 03 09:14 AM
Slow Cruising Speed Question Curtis CCR General 0 September 19th 03 10:41 PM
Narrow hull speed question Robert Haston Boat Building 5 September 15th 03 07:45 PM


All times are GMT +1. The time now is 06:30 AM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 BoatBanter.com.
The comments are property of their posters.
 

About Us

"It's about Boats"

 

Copyright © 2017