Bowtiepower00

Sounds like karma for teasing all of the northerners about your warm temps and great boating weather!!

Just kidding, sorry to hear about your misfortune, LOVE that Sonic... Man it turned out SUPER CLEAN, better hold onto it, even if you get bit by the cruiser bug...

I can hear Jimmy Buffett in the background... Boat Drinks.... The boys in the band order boat drinks...

Boat turned out killer, hope you get it back up and running soon... you know you love rebuilding those OB's...

Twin O/B Sonic

for the kind words. It's interesting that every time I get serious about looking at something bigger (most recent being the 31' Sonic O/B) I am reminded why I like this boat so much.

If all goes well, the p.head will go back together this weekend.
As I told the Mrs on the way back to the trailer on one motor, "we could have a payment, so no whining allowed".

I am also more convinced the only way I'll get something I like better is to either build it or convert an I/O boat to clip ons.
Or I could raise the deck on a 30' Velocity...........

mysweetone

I love snowmobiliing! Just spent three days in the northern most part of NH! Gods land up in them thar' parts!

JUPITER PULSARE

Maybe you should convert it to Merc 2.4's or 2.5's! They're readily available and reliable as long as you keep the carbs clean!! My 2.4's are pushing my big 28' Checkmate into the upper 60's and hopefully into the low 70's when I try my DAH Chopper 26's next weekend!!

Ernest T Bass

OH!!!

Twin O/B Sonic

2.4's and I repowerd w/new versions of what are on this boat and never looked back. Not even close.
This boat had 225 3.0 EFI Mercs when I bought it and ran a best of 67 and it has run 71.4 so far w/my built from spare parts, carbureted 3.0 JohnRudes w/o trying. Probably carrying 3 - 400lbs more weight now too.
Old boat ran 80.
What happened to this motor is specifically due to me playing with them and why I have no problem writing about or posting pix's of it.
If I had left them stock, they'd still be fine.
I ported these blocks myself, cut .100" (do the math, thats almost an 1/8" ) off the heads and cut my own chamber design into them. One wizard told me this is too much to still have enough meat to dissipate heat to prevent detonation but I normally don't listen to those smarter than me.
I am also running approx. 10 more lbs of compression than what anyone else does w/these motors, in this application. So two things pointing to impossible.
I had a pre-existing issue (for this application) of air pockets in the top of the water jacket in the block (described earlier in this thread) that would not have bit me if I had either, A. fixed it, or B. kept my hands out of the motors. So 3rd issue.
In my world though, stock is absolutely unacceptable and I have learned much by swimming up stream.
The 2.4/2.5's are great motors but not for pushing this much weight as you will find out. (Weren't you predicting 80 for yours when I got laughed at for predicting mid 60's??)
Counting both the 24' Sonic's I've owned, I have over 11 yrs w/them collectively. Restored, repowered both. During that time (again, 11 yrs), I've only heard of one faster (w/2.5's) but never seen one Most run low/mid 60's.
I also built a pair of the OMC Lightning Hi Prerf L/U's for this boat. Counter rotating too which they never offered from the factory.
On a 24' Superboat or a 24' Skater OK.
A pig like my Sonic....., no replacement for displacement.

ziemer

iTrader: (1)

What's the fix?

Bring the compression back down a bit...stock or closer to stock heads to help dissapate heat, fix the steam issue, or just a combination of all three?

Does the higher compression gain you much on a heavier boat like yours?

To help you feel better here's a pic of one of my current projects on the 30...Be glad you have the clamp-ons... Lol... Plus, I've got the K-planes apart and being painted, along with new indicator cables, new thermostats, and re-painting battery trays. Oh yeah, I got a drive leaking at the shifter so that needs to go down to Colabella... Yay!

Twin O/B Sonic

My next test will be venting the top of the block's which I had to do to my hot rod 3.3 and fattening up the mid range jets.
At that point it will be a crap shoot w/octane.
The compression helps acceleration but this boat runs so much different from my old I can't really tell.
I think I can get by w/89 if I'm careful and based on what the other 5 look like, I'm fairly confident of this. I mean really, what can possibly go wrong

Hate seeing your problems Jeff but I think we all know to expect them on an older boat like ours. Like I already said, we could be making payments.
Funny too, I stopped at a local boat shop the other day to look at an old 28' (I think) Chris Craft Stinger they were working on.
Was telling the guy about my current 2' itch and that one of my stumbling blocks of going bigger was going the I/O route.
Should have heard his reply He had just spent a pile of hrs removing, re-sealing the transom rings on both drives among other issues do to little/no PM on them. I reminded him of the money he was making. He didn't care.
Made me feel a little better anyhow

ziemer

iTrader: (1)

I'm just thankful I can do most of this work myself, and have some great contacts here local when I need some guidance.

My goal is to have the other gimbal apart by the weekend and hopefully start putting some of the other stuff back together (tabs, batts, thermo's, etc) this weekend. Then hopefully, I can start getting the gimbals and bells back together next weekend.

Next after that will be the trailer...

JUPITER PULSARE

Hey Gary, the Ocean Outboard Race boat with twin 2.4 bridgeports ran 78-82 mph (same AME 4000 layup and setup as my boat). My boat with twin 2.5L 260's/20" Offshore mids/Sportmaster gearcases ran mid 80's + and with stock 2.4L 200's ran 72+ (which is what I'm duplicating right now). I'm hoping to build a couple strong 2.5L fishing motors and get the boat into the upper 70's as time and money allows. For comparison, Wildmans brand new twin outboard Convincor ran 70+ with stock Merc 3.0 L 225's....Sof far my boat has ran 68MPH GPS turning HUGE 15" diameter 4 blade Suzuki 24 pitch props with 0 slip. I bought a set of Merc DAH worked Chopper 26's which I'll run this weekend. I'm sure I'll break the 70 MPH mark with these props. If anyone can make a pair of JohnnyRudes run, your the man. I'm sure you'll get her back together quickly and then we'll have to hook up and do some twin engine egg beating sport boat runs!!!