Go Back   Maxum Boat Owners Club - Forum > Maxum General > Engines
Click Here to Login
Register FAQ Community Calendar Today's Posts Log in

Reply
 
Thread Tools Search this Thread Display Modes
 
Old 05-21-2023, 07:59 PM   #1
Ensign
 
Join Date: Jul 2021
Posts: 12
Default 4.3mpi engine problem

Hi lads
over winter the exhaust manifolds cracked from frost and i repaired them and i also at the end of last year it revving very high when changing between forward and revers so i adjusted the cable
now I'm having a problem with lack of power it takes ages to plane
any suggestion?
thanks for reading
Simon
__________________

sistack is offline   Reply With Quote
Old 05-22-2023, 01:23 AM   #2
Admiral
 
mmwjr's Avatar
 
Join Date: Feb 2012
Location: Essex, Maryland
Posts: 10,606
Default

Please elaborate on how the manifolds were repaired. Also what cable did you adjust? Was the boat stored in the water for the winter?
__________________

__________________
1997 Silverton 362, 7.4 Crusaders
1997 2400 SCR, 5.7 Vortec / Bravo 2

Mike
mmwjr is offline   Reply With Quote
Old 05-22-2023, 05:48 PM   #3
Ensign
 
Join Date: Jul 2021
Posts: 12
Default

no the boat was out of the water over the winter
both manifold had large cracks on the out side face which i brazed them back just like new
the the cable I adjusted was the long cable that goes to the hand controls
it now goes into gear with nicely I adjusted it as the engine was revving very high and cased the boat to bang into gear
now it just takes twice as long to plane and is even worse if i towing someone on ski's or wake board
thanks Simon
sistack is offline   Reply With Quote
Old 05-22-2023, 07:16 PM   #4
Ensign
 
Join Date: Jul 2021
Posts: 12
Default

no the boat was out of the water over the winter
both manifold had large cracks on the out side face which i brazed them back just like new
the the cable I adjusted was the long cable that goes to the hand controls
it now goes into gear with nicely I adjusted it as the engine was revving very high and cased the boat to bang into gear
now it just takes twice as long to plane and is even worse if i towing someone on ski's or wake board
thanks Simon
sistack is offline   Reply With Quote
Old 05-22-2023, 08:04 PM   #5
Admiral
 
mmwjr's Avatar
 
Join Date: Feb 2012
Location: Essex, Maryland
Posts: 10,606
Default

Sounds like you adjusted the upper shift cable that goes between the helm control and shift bracket; correct? Or was this the throttle cable which goes between the helm control and throttle body? Once on plane can you achieve proper WOT which should be 4400-4600 rpm?
__________________
1997 Silverton 362, 7.4 Crusaders
1997 2400 SCR, 5.7 Vortec / Bravo 2

Mike
mmwjr is offline   Reply With Quote
Old 05-22-2023, 08:18 PM   #6
Ensign
 
Join Date: Jul 2021
Posts: 12
Default

thanks for the reply
yes the upper shift cable
no I'm not getting that high I'm only getting to 3500
sistack is offline   Reply With Quote
Old 05-23-2023, 02:17 AM   #7
Admiral
 
mmwjr's Avatar
 
Join Date: Feb 2012
Location: Essex, Maryland
Posts: 10,606
Default

I would perform a compression test to verify all the cylinders are good.
__________________
1997 Silverton 362, 7.4 Crusaders
1997 2400 SCR, 5.7 Vortec / Bravo 2

Mike
mmwjr is offline   Reply With Quote
Old 05-23-2023, 06:54 PM   #8
Ensign
 
Join Date: Jul 2021
Posts: 12
Default

it was running perfectly before i took it out for the winter
what could have happened to it over the winter that would cause low compression ? please excuse my questios this is the first boat engine I've worked on normally it's classic land rovers
thanks Simon
sistack is offline   Reply With Quote
Old 05-23-2023, 08:52 PM   #9
Admiral
 
mmwjr's Avatar
 
Join Date: Feb 2012
Location: Essex, Maryland
Posts: 10,606
Default

If the manifolds cracked then the engine block or heads may have a crack as well. Was the engine winterized?
__________________
1997 Silverton 362, 7.4 Crusaders
1997 2400 SCR, 5.7 Vortec / Bravo 2

Mike
mmwjr is offline   Reply With Quote
Old 05-23-2023, 08:58 PM   #10
Ensign
 
Join Date: Jul 2021
Posts: 12
Default

yes it was but i don't know if the mix was correct ( the cracks kind of prove it was lean lol)
i did check the oil and there is no water in it
the boat is 3 hour away and wont get down till the weekend with work
sistack is offline   Reply With Quote
Old 05-24-2023, 01:34 AM   #11
Admiral
 
mmwjr's Avatar
 
Join Date: Feb 2012
Location: Essex, Maryland
Posts: 10,606
Default

Low power could be the loss of a cylinder the other thing to do is have a mechanic read out any codes from the ECM which requires a special reader.
__________________

__________________
1997 Silverton 362, 7.4 Crusaders
1997 2400 SCR, 5.7 Vortec / Bravo 2

Mike
mmwjr is offline   Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

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


Powered by vBadvanced CMPS v3.2.3

All times are GMT. The time now is 01:01 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2024, vBulletin Solutions, Inc.