Thank you very much for the info and the chart.  Will measure when i get home tonight.  When you lube the U joints via the zerk (when its back in the boat) - what is the best way to know when to stop?  thanks again

Usually only takes a pump or 2.  You'll hear it kind of crackle and pop.  You don't need, or want to pump it until it pushes out, that just makes a mess.  If you want to inspect them for wear, it's very simple.  Hold the cap in your hand and slowly pull the joint up twisting it as you pull.  This way the needles should stay in the cup.  Inspect the joint where the needle bearings contact  the surface for any grooving.  If it's smooth, wipe a little grease on the needle bearings and carefully spin the cap back on the joint.   If you see rust or grooves, then I would replace them.

Take the head from the dirty side and poor some type solvent or even water into the combustion chambers.  Fill the chamber higher than the valves and see if the liquid runs out the spring side of the valves.  Could be valves not sealing allowing the combustion gasses up past valve seals like Flusher's saying.  That would also explain your low compression.

I always try to advise friends looking at boats or toys like this to make an estimate.  Try to do a thorough, un-emotional evaluation on what the boat is going to need just to make it acceptable to you.   Does the trailer need tires, lights or bunks, does the boat need a battery, upholstery, cables, motor work, pump work, hull repair.  Are the stringers "Iffy".  And for this estimate you need to figure how much your time is worth to do the repairs.  Not $65.00 an hour, but your time is worth something, a couple hundred bucks to maybe $500.00? 
Normally a boat like this is going to need at least a few things  I listed.  It's pretty easy to drop another 2000.00 to  2500.00 quick.  Just ask all the people on hear that only got 10 minutes to 3 hours on their boat before they were rebuilding engines.   So, for round numbers, if you can add up the obvious needs and come up with $2000.00 in repairs plus the asking price of $1700.00 this is actually a $3700.00 boat. 
Take a minute and shop $4000.00 boats and see what you can buy for 4G's.
 For 4G's you'll  probably get  a much nicer boat that's water ready, or one that will be worth a lot more if you have to invest a few bucks.
I hope you get my point.  This isn't a $1700.00  boat in reality it's a $4000.00 boat.

What kind of tips do you have?  I have a set of covers I'm removing because I'm going back to logs.  I'll get a pic of them when I get home.

What do your tips look like?

What kind of tips do you have?  I have a set of covers I'm removing because I'm going back to logs.  I'll get a pic of them when I get home.

Logs sold thank you, Mash On It!

Parting out Day Cruiser.  Good stuff  for anyone doing a budget build.
Tanks with mounting tabs and senders.  Aprox 25  gal-  $100.00  (SOLD)
Tanks with out tabs (red), they do have senders Aprox 25 gal- $75.00
Good wiring loom complete, no splices, from 21' boat  -$25.00
Berkley pump in good working order.  Didn't take it apart, but guessing an A imp - $150.00
Holley Blue electric fuel pump with fuel filter and Y fitting - $50.00
Swim step with fold down ladder - $25.00
Trim tabs - $20.00
Nicson Exh Logs SBC, good condition -$100.00.  (SOLD)
SBC Motor.  Runs good.  It came out of a car and was put in the boat.  Ran good all summer.    I rebuilt the carb.  I replaced the alternator and starter (reman).  This motor would be a good drop in for a truck or car that just needs a running engine -$200.00 (SOLD)
Open to any reasonable offers 
text 951-452-2213

I wasn't going to.... but I can't help myself.  I'll tread lightly.  My 454 bored .100 over and stroked with a 4.250 crank and 4.135 rod's only comes to 505CI.  And a 671 Mooneyham blower, aluminum heads, and 2 C&J  worked 850 dp Holley's made a respectable 826 HP on the dyno.

 
And, impellar blade pitch is the same on AA, A, B, C,  etc.  It's the impellar size that makes it an A,B or C cut..
 
But good luck with your sale.  Maybe you'll have better luck on  the East coast where jet boats are rare.

What intake are you putting in it?  Something really cool and trick I suspect!!

It's since been painted (Twice!).  If I only had Sam's talent with a spray gun.

I think this falls into the category that most our boats aren't near efficient enough, and our set ups aren't good enough to worry about how much effect scoop design is going to have.  How many boats run the Dooley style scoops in everything from drag boats to GN boats.  There's not a whole lot of engineering in those scoops.  If you're set up is so efficient that your looking for .010 or .001  of a second then maybe spending a bunch of time working on air flow induction may be a concern.  For me it's more about cosmetics or the look.  I run spark arrester's in my scoop.  I ran them on the dyno and found they only cost me like 1% in HP.  That's not enough to worry about in a play boat IMO.

Chief Keef, you see these posts just as much as I do, feels like weekly that people want to know this that and the other about why their boat is so slow or what mods or parts would add mph....
I got an idea...dial your shit in!
Make sure your pump is right, how bout a cap and rotor and wires and plugs and a carb rebuild and have have someone who knows what they are doing dial it in.....

My fat hog had a bazillion hours on it with plug wires from 1984 and did 55mph all day.
Faster than I ever thought it'd go.
All I've ever done is kept the pump tight, changed the plugs, oil...

Blah blah blah.....
I'm just rambling.
Don't mind me, it's not like I own a boat.
What the hell am I doing here anyways???

-beerjet-

Spoken like a true Veteran!!!      We all understand the K.I.S.S.  method until it's our own shit.  Then it becomes rocket science.