Bow too high at launch, won't level out

romoguy15

Cadet
Joined
Aug 21, 2018
Messages
14
Hello, first of all I'd like to apologise if I don't use the correct boating terms to explain my issue.

I recently aquired a 1995 Crownline 225 CCR with a 350 magnum alpha one 400hrs. I took the boat out for the first time with family, we had 5 people on board including me. The issue that I am having is when I take off, the bow will not come down unless one of the passengers moves towards the front of the boat. I have my trim all the way down. I have it at fullThrottle, rpm doesnt go above 3500 nd it just won't accelerate any further until we shift some of the weight forward. Once that happens, it will level out and pick up speed no problem and it reve up no problem. I will get the specs of the prop soon. Do I need to replace the prop? If so, what prop should I get so I can fix this issue. Thanks
 

romoguy15

Cadet
Joined
Aug 21, 2018
Messages
14
Yes, it does go over 3500rpm with just me on it. But with other people, it will not ever get out of the hole unless weight is moved to the front. Even after weight is moved forward, it will take a minute to level out.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,306
what RPM do you get with just you on board?

go thru the low WOT check list that I linked you to.
 

romoguy15

Cadet
Joined
Aug 21, 2018
Messages
14
I honestly do not know what rpm I reach. I will take it out tomorrow and do a test run to see. I did go through that list of possible low WOT and I have no idea what it could be. The only thing I can think of, is incorrect prop size or maybe there is something restricting the fuel line. Should I get the information of the prop size and report back?
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,306
no, you should check compression, check fuel pressure, etc. to make sure your motor is putting out the correct power.

did you do any maintenance on the boat when you got it?
 

romoguy15

Cadet
Joined
Aug 21, 2018
Messages
14
Okay sounds good. If I am able to reach over 3500 rpm by my self, is it still necessary to do a compression test and fuel pressure test?
 

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Being a second hand combo and if engine runs strong, seems was propped wrong by last owner. Make a hub slip test to check if current prop is doing its homework right, if so, need a much less pitch prop to pull wot revs up. Dial a prop for engine to rev middle to max wot rpm range as usually loaded.

When boating with several boaters need to distribute deck load evenly stern to bow, combo will plane much faster and if well propped much better. Need to know the factory min-max wot rpm range specs to play correctly with props.

Happy Boating
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,036
A 22 footer with a 350CID motor should not be underpowered. Either the prop has too much pitch or the motor is not making the normal amount of power.

Take a compression test and examine spark plugs. They should look the same. Then post full throttle RPM with 2 people and normal gear. That should help pinpoint issue.
 

romoguy15

Cadet
Joined
Aug 21, 2018
Messages
14
Thank you all for the replies. So I found out that the propeller was changed. I will get the prop checked and tested and also do a test run to make sure engine is running stong.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,306
Okay sounds good. If I am able to reach over 3500 rpm by my self, is it still necessary to do a compression test and fuel pressure test?

yes. it is necessary to go thru everything to find the problem

also go thru the other things in the checklist. prop and gear ratio are also things to check.
 

romoguy15

Cadet
Joined
Aug 21, 2018
Messages
14
I am gonna to take the boat out this afternoon for a test ride. I will report back in a few hours. I'll also take note of the prop specs. I'll have to get with a mechanic to check the engine and other items.
 

romoguy15

Cadet
Joined
Aug 21, 2018
Messages
14
Okay, update. I took the boat out for a ride by my self. I full throttled it and reached a max RPM of about 4100. Top speed was 46mph. The current propeller installed is a Rubex stainless steel 4 blade, 14.25x19. Do you guys have any thoughts?
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,306
was the speed per GPS? or the speedo?

the prop slip numbers look good

I would go to a 3-blade 19p and test it. (most marinas have test props) you should be spinning about 5000 RPM with the 350, however not sure on the Rubex 4-blade
 

89retta

Senior Chief Petty Officer
Joined
Jul 18, 2010
Messages
772
Do you have the drive trimmed all the way down when starting off ? Sounds to me like you have it up some
 

romoguy15

Cadet
Joined
Aug 21, 2018
Messages
14
The was speed was on an app on my phone using GPS. And yes, I had it trimmed all the way down.
 

romoguy15

Cadet
Joined
Aug 21, 2018
Messages
14
was the speed per GPS? or the speedo?

the prop slip numbers look good

I would go to a 3-blade 19p and test it. (most marinas have test props) you should be spinning about 5000 RPM with the 350, however not sure on the Rubex 4-blade

I was using an app on my phone that uses GPS. I do keep the boat at a marina so I may ask them for test props.
 

romoguy15

Cadet
Joined
Aug 21, 2018
Messages
14
My goal is to be able to improve acceleration, and be able to level out without having to shift the weight. I do not mind losing top speed.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,306
Start going thru the check list. My guess is either your down a cylinder, or you dropped a flapper
 
Top