Prop questions

[JOFO17]

I have a 21' Dixie cuddy Cabin with an 87 Johnson 140 looper on a bracket . Had it out first time yesterday and ran 4800 rpm wot using a 3 blade aluminum prop measuring 15x17. Was able to do 30 mph. Is this good??? Bigger issue seemed to.be how far down in the water the motor was going. It was almost up to the shroud unless I tilted the motor up some. Even then I could see the bracket was in the water causing drag. Any input is appreciated.

 

[Frank Acampora]

No, 30 is not good You should be able to do mid thirties and possibly as high as mid 40s. As an example: My Manatee cuddy cabin did 33 with a Force 125 and 40 with a force 150.

First thing to do would be to check the engine--compression timing, spark on all cylinders, etc. The Bracket should be mounted so that it is completely out of the water at plane so also check that the hull is not waterlogged..

 

[steelespike]

The motor is rated for 5500 rpm. With a 17" pitch it should be closer to 5500.
How old is the Dixie?Dry weight? If stored improperly over the years it may have absorbed water in the foam under the floor.
If you raise the trailer at the bow and remove the drain plug once the loose water is out if you still get water dripping
it could be an indication of saturated foam.

 

[JOFO17]

When I get home today I'll jack the front up way high and see if water drips as you said. Engine is fine, It was just serviced at a reputable dealer who said it's in good shape. Not sure of the actual dry weight but specs say 3000 lbs.

 

[jbcurt00]

If bracket is in the water while running on plane and motor is in the water nearly up to the shroud (cowl) theres something foing on beyond the motor mot reaching 5500rpm at WOT.

Unfortunately, waterlogged foam is a sponge and may not weep much water but could still be extremely waterlogged. I'd weigh the setup as it sits now. If you can weigh the boat and trailer, then launch the boat, go back and weigh just the trailer, you can get the boat weight. I can go across my local recycler's scale anytime for free as long as theres no line for the scale. Never had to wait for more then 1 truck in front of me.

Why is the OB on a bracket? I/O conversion?

Is bracket mounted correctly?

A new to you 1987 boat that has had work done (bracket was likely added by an owner and not factory) is always suspect for water intrusion, IMO.

If the motor is so deep that water is nearly upto the cowl, its creating a huge amount of excess drag as is the bracket if its underwater while on plane. Enough to lug the WOT down 700rpm to 4800? I'd guess yes....

A pix of the transom setup would be helpful, showing bracket placement on the hull and outboard/bracket alignment to the keel/bottom of the hull.

 

[JOFO17]

Believe it or not it is a factory set up. I'll see if the scrap yard up the street will let me weigh the boat. But first thing I'm going to do when I get home is see what hole the motor is mounted on. I kind of remember putting it in the top hole. May need to move it to the bottom mounting hole.

 

[JOFO17]

No Title

I haven't done anything so far since clocks were set back, but did get some pics. Sorry if pics are upside down. No idea why.

 

[flyingscott]

When you are running check and see how deep the motor is in the water. What people don't realize is when you set the motor back you also need to raise it up. The reason the transom angle will lower the motor the farther out it is. Also the displaced water rises behind the boat also lowering the motor.

 

[JOFO17]

It only seems to be low in the water when it's running. It's worse when just going slow then it is when on plane. It seems to lessen if I tilt the motor up some.

 

[flyingscott]

Try this when running flat out you should be able to see the cavitation plate

 

[steelespike]

When the bow rises the pod will tend to be closer to the water The motor may need to be raised to counter this effect.
Motors on jack plates only 8 or 10 inches set back will also need to be raised.
You can imagine the affect your 18"? bracket may have.
At rest In the water is the water about at the water line on the bracket?

 

[JOFO17]

It looks good at rest. It doest take a dive until I put a load on it. It's worse at slow speed before I get on plane. Tonight I'm going to lift the motor as far as it will go. It's presently set in the top hole so I do have some room.

 

[steelespike]

If it looks good at rest Your not likely to have a water soaked problem.

 

[Scott Danforth]

I haven't done anything so far since clocks were set back, but did get some pics. Sorry if pics are upside down. No idea why.

because you took your pictures with a cell phone (most likely an iPhone) and had the phone upside down. computers do not auto-rotate the pictures

regarding your bracket, it looks like the motor is at the right height when mounted to the transom. sitting back the 2' on your bracket, the motor should come up a good amount. I would assume 4" as a start. may have to go to 6" if you could swap to a short shaft that would get you 5" right there