Author Topic: Anyone running 70-80hp motor on a CVX16?  (Read 533 times)

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Offline Buckey

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Re: Anyone running 70-80hp motor on a CVX16?
« Reply #20 on: January 18, 2021, 07:49:50 PM »
I look thru my "Boat Mfg. Codes" and didn't find any DeltaCraft listed .. or the ZLE code ?
But remember I also couldn't find the Swiftsure code ..

Will be interesting to see how they built your boat, some early CVX's had fuel tank running front to back and newer versions running side to side. Not sure but I've been told that older versions had a small piece of transom wood and latter versions had full width wood that was tabbed and glassed better.

My foam under floor and in stern boxes was dry, but wood floor under splash well, even though coated with resin, was rotted and transom wood behind left side was so bad (rotted) that I removed it with my fingers.

The mileage we get on the river run was 50% cruising (30 to 40 mph) 35% full or almost full throttle and 15% no wake / idling.
If you were pulling kids around on a tube all day at 30 mph you would most likely get much better MPG.

1982 was first year for prop rated 115 HP Merc / Mariner's and with some set up and prop testing get you mid 50's pretty easily.
I'm getting 53 to 54 MPH / GPS with my CV16 / 1989 115 HP Mariner and Dave's get a few mph more with his CVX16 / Johnson 115 HP.

Your bolt hole's in transom will be different from the Mariner to the 75 HP OMC motor.

This build still has some pictures ..
 http://www.classicglastron.com/phpbb/viewtopic.php?f=34&t=6642

Thanks for all the great info.
Ah, so you have a 115 Mariner.  I'll have to learn about some of the things to look out for when I go to pick up the motor.  As far as the boat goes, there is a bit of floor under the splash well that's showing a bit of rot.  The foam boxes are both split, meaning maybe they soaked up some water at some point.  Oh, and here's another thing, I need to repair the transom on both sides as the owner that consigned it, at the marina its at now, brought it there with no suspension on the trailer, and no transom saver on the motor/leg so that was enough to crack the transom on both sides.  Hull is all good though, not a scratch, and no stress cracking.  I'm ok doing the transom repair.

I wonder why the 115 is getting more top end than your Mariner?
The trim on my 75 leaks down so I'm fixing that, how do you find the quality of the trim on the Mariner?
I'll check next time I'm out there and take some pics of the transom and gas tank.



Offline Buckey

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Re: Anyone running 70-80hp motor on a CVX16?
« Reply #21 on: January 18, 2021, 08:17:36 PM »
I look thru my "Boat Mfg. Codes" and didn't find any DeltaCraft listed .. or the ZLE code ?
But remember I also couldn't find the Swiftsure code ..

Will be interesting to see how they built your boat, some early CVX's had fuel tank running front to back and newer versions running side to side. Not sure but I've been told that older versions had a small piece of transom wood and latter versions had full width wood that was tabbed and glassed better.

My foam under floor and in stern boxes was dry, but wood floor under splash well, even though coated with resin, was rotted and transom wood behind left side was so bad (rotted) that I removed it with my fingers.

The mileage we get on the river run was 50% cruising (30 to 40 mph) 35% full or almost full throttle and 15% no wake / idling.
If you were pulling kids around on a tube all day at 30 mph you would most likely get much better MPG.

1982 was first year for prop rated 115 HP Merc / Mariner's and with some set up and prop testing get you mid 50's pretty easily.
I'm getting 53 to 54 MPH / GPS with my CV16 / 1989 115 HP Mariner and Dave's get a few mph more with his CVX16 / Johnson 115 HP.

Your bolt hole's in transom will be different from the Mariner to the 75 HP OMC motor.

This build still has some pictures ..
 http://www.classicglastron.com/phpbb/viewtopic.php?f=34&t=6642

I was looking at your reply again, and noticed the link to a restore thread.  Wow, someone did a great job on that restoration, nice boat.  I like the triangular supports back to the transom.  And air chisel, great idea.  Any boat this old I suppose is going to need some attention, I'm hoping I can avoid extensive restoration though.  I didn't go to the extent like this when I did the Banshee, but I remember it was a dirty job, very important to be prepared with all the right gear for the job.
« Last Edit: January 18, 2021, 08:24:47 PM by Buckey »

Offline Hyperacme

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Re: Anyone running 70-80hp motor on a CVX16?
« Reply #22 on: January 18, 2021, 08:31:01 PM »
From the picture you posted your Mariner has old style tilt and trim with external trim rams. But according to chart I posted it is a ADI ignition system.
My Mariner is first year for the four cylinder 2+2 115 HP motor ( same motor as 100 HP pictured below )  and has internal three ram system.
After the 100 & 115 HP Merc's came out they started breaking cranks ..so Merc issued a service bulletin to reduce rpm's down to 5250 max rpm's from the 5500 rpm max of older inline six motors.
I believe that hurt performance some .. but Dave's CVX is faster mainly because his, and all CVX16 / C500 / CSS16's have a pad where the CV16 has a rounded bottom. 

Bottom picture is CV16 hull and CVX16 hull with pad ..
Gregg
'76 CV16

Offline Buckey

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Re: Anyone running 70-80hp motor on a CVX16?
« Reply #23 on: January 18, 2021, 09:15:00 PM »
From the picture you posted your Mariner has old style tilt and trim with external trim rams. But according to chart I posted it is a ADI ignition system.
My Mariner is first year for the four cylinder 2+2 115 HP motor ( same motor as 100 HP pictured below )  and has internal three ram system.
After the 100 & 115 HP Merc's came out they started breaking cranks ..so Merc issued a service bulletin to reduce rpm's down to 5250 max rpm's from the 5500 rpm max of older inline six motors.
I believe that hurt performance some .. but Dave's CVX is faster mainly because his, and all CVX16 / C500 / CSS16's have a pad where the CV16 has a rounded bottom. 

Bottom picture is CV16 hull and CVX16 hull with pad ..

Thats a nice boat and motor combination, looks like you did a full restoration.  Thats the best way really, then you know what you have and its safe.  Mine has that flat bottom hull pad to.  To bad it -20 here, long way to nice summer days for a burn in the boat.