Mercruiser 165 ??

[JimCt]

To add to what RickK said, watch the water flow too.  If you don't see cooling water exhausting when you start it, shut it down or you'll melt the exhaust hose and bellows since they are water cooled.

Slight de-rail:

Still can't get it through my head how bunk trailers are claimed to provide better support.  The trailer I'll get for the 240 will likely have 48 rollers.  That's 48 self-adjusting, conformal rollers which will pivot to match the shape of the boat.  Bunks are not conformal as far as I know so they cannot support the hull's weight equally along their lengths.   If bunks do provide better support, I'm missing something here...

[GoneFission]

Bunks versus rollers - the never-ending story.  But here are the physics behind the bunk story:  If the bunk is connected to the trailer at the ends, it will deflect over time to exactly fit the contour of the boat bottom.  So you have about a 1" to 2" by whatever length of bunk contact.  Let's say the contact of the bunk to the boat is 10' - thats 120 in. x 1 in. = 120 sq. in. X 2 (bunk on each side of trailer) = 240 sq. in.  

Rollers make point contact - the average roller only has about a 1/4" wide contact with the hull.  Assuming a double roller, with each roller 2" wide, that's 2 x 2 x .25 = 1 sq. in. per double roller.  So you would need 240 rollers to equal the contact patch of the bunk.  

If the bunk makes full contact - say 2" - well you can do the math.  

I switched from a roller trailer to a bunk trailer because it lets the boat sit lower on the trailer - easier to launch and retrieve.  I put 2 rows of the 1" wide Glyde-Stiks on the bunks so the boat goes on and off like it was greased.  but let's look a support:  2 rows of 1" Glyde-Stiks equal 2" wide contact patch for the outboard bunks plus the bow bunks.  I have a total of about 14 feet of support on each side - that's 28 total linear feet of support times 2 inches wide times 12 inches per foot = 672 sq. in. of support under the hull.  With a 3500 lb. boat, thats only about 5 lbs./sq. inch of stress on the hull.  And the bunks extend a little past the transom, so there is no chance of putting a "transom hook" on the hull.

[JimCt]

Thanks GF!  First coherent description I've read.  What are the launching/retrieving circumstances where a bunk trailer would not be a good choice?

[GoneFission]

The only one I have experiened is on a very cold day, when the bunks were frozen to the hull - and the weight of the trailer pulled the back end of the boat under water when launching...  

Of course, as soon as the bunks thawed under water, the boat popped back up - with about a foot of water inside!  

Just another day on the water - hey, if every day was the same, it would be sooooo boring.  Boats and Mother Nature conspire to make our lives more interesting - don't you think?  
 

[JimCt]

Do you see any limitations as far as the angle of the ramp is concerned with a bunk trailer?  At some ramps in this area I doubt I could get a bunk trailer in far enough for a complete "float-on" retrieval.

If it's cold enough to freeze the boat to the trailer, I'm staying home.

[GoneFission]

That's why I switched from roller to bunks - the bunks allow the boat to sit lower on the trailer and float on and off easier on shallow ramps.  With the Glyde Stiks, forward bunks, and guide-ons in the back, putting boat back on the trailer is almost fool-proof.  Notice I said "almost..."  Murphy and his law still win every once in a while!  

On steep ramps, the Glyde Stiks are slick enough that I have to keep power on until the front hook is engaged or the boat will slide back in the water.  

Regarding cold weather - it seems the colder it is here in the Carolinas, the better some species bite (especially Striped Bass).  Here are some hardy souls that went out of Oregon Inlet on Friday:  



See ya on the water!

[JimCt]

Looks like everyone went home with some nice fillets.  Any special way you cook them?

Thanks for all the info. GF!  Now you've got me thinking seriously about a bunk trailer...

[sturgeon]

  Don't give up on putting in a new I/O unless you are mainly going to fish in shallow water.  A new 3.0 liter will push the boat great, get 5-6 mpg and cost less than a comparable size outboard would even with a new lower unit.  You can also add a jackshaft and move the engine forward if you want.  Lots of good options these days. Good luck.

[sturgeon]

 I would not give up on replacing the I/O too quickly as you can get a new 3.0 ltr and outdrive for less than a 115 outboard and get gas mileage in the 5 to 7 mpg range.  Not to mention that you would have significantly more torque available.