How safe is an older Checkmate?

[Victorious1]

I was reading a thread here that really got me thinking about my 1978 Checkmate Inmate powered by a Mercruiser 3.7 stern drive.

What should I be looking for on this boat to help assure me that it is in the best condition for safe operation at 60 M.P.H.

Most older boats I have ever seen have some small stress cracks here and there on the flimsier portions of the upper deck. Does this mean they are unsafe? And can these stress cracks be repaired reliably? Mine has a few where you would place your feet to climb in and out of the boat.

The hull/bottom on my boat has no cracks at all and the transom fiberglass looks like new. It's original paint on this boat(metalflake) and the clear coat has some minor cracks in it.

How do I determine if my boat is solid core or balsa core?

It would sure bring a lot of peace of mind to me if some of you highly experienced experts spoke up about some of these issues.

Thanks guys. Your wisdom and experience is very much appreciated.

Vic

 

[175checkmate]

I would say that about 70% of all stres cracks only run as deep as the jell.
My boat had a few of them. When I was doing the rebuild on the transom and I looked at the stress crack. I found that they are what I would consider surface cracks.
As for the core, well can't help you there. Othere than you can get a decent idea about the condition by taping with a rubber mallet. It if sounds soilid then it is proably alright.

 

[cooperider]

Have a Marine Surveyor look at it and buy yourself some piece of mind. They will tell you what to worry about and what not to worry about.

 

[Victorious1]

Trouble with a marine surveyor is that unless they are your best buddy or they have deep passion for their job they only give routine information that costs a lot of money.

That's why I'm asking out here for tech advice on the safety of older Checkmate boats/hulls. There's lots of hands on experience out here and the passion is very evident. I have seen a lot of extremely accurate replies out here and feel very confident with most responses and that's why I posted a request for this forum's experience and wisdom.

Vic

 

[DONCONVINCER]

The Inmate is a realy cool boat. I don't think you have any thing to worry about on the transom being its an I/O. Things you can check is the floor and the panels on either side of the engine where the gas tank and battery mount also check your engine mount stringers. Is any wood delaming or peeling? Has anything ever been drilled into the engine stringers except the engine mount bolts? Pull the engine mount bolts, is there any evedence of moisture? If your answer is no to all the questions I'd ride with confidence....

You also asked about the core.. Your boat has cored hull bottom and transom and fiberglass sides. Unless the boat has had some major work done or damage to the hull that would compromise the outer shell the core should be ok. If the floor has rot you should look for rot in the core and stringers when the floor is done.

Now as for the top deck.. It has structural charactistics but keep in mind it's riveted to the hull. The top deck only may stop some hull flex, small cracks won't make your boat unsafe

If you don't find visable rot have fun....

Now if want to have lots of fun repower that thing with a V8....

 

[jrumon]

Stress cracks are 99% surface flaws... more presend on clear-coat gel over metal flake. I don't know why other than the clear may be less "flexible" than solid colors or if it's the metal flake underneith that catches the sun and plays havoc on the clear. For whatever reason, the small stress crcks are of little concern.

The BIG concern is the CORE & TRANSOME of the hull. Floors are no big deal, but if the bulsa coring got wet (saturated... the hull is scrap unless gutted and re-cored (SPENDY$$$$)! I've looked a few older mates that were nice looking but water-logged cores big time... Transom wood can also do the same if things weren't properly sealed (O/I's and outboars)... so look carefully! Good luck, Jim.

 

[DONCONVINCER]

I agree with Jim that a wet core is a big problem. Check the floor real good for rot and the back floor verticle part in the engine compartment for indicators of moisture.

 

[Victorious1]

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by DONCONVINCER:
The Inmate is a realy cool boat. I don't think you have any thing to worry about on the transom being its an I/O. Things you can check is the floor and the panels on either side of the engine where the gas tank and battery mount also check your engine mount stringers. Is any wood delaming or peeling? Has anything ever been drilled into the engine stringers except the engine mount bolts? Pull the engine mount bolts, is there any evedence of moisture? If your answer is no to all the questions I'd ride with confidence....

You also asked about the core.. Your boat has cored hull bottom and transom and fiberglass sides. Unless the boat has had some major work done or damage to the hull that would compromise the outer shell the core should be ok. If the floor has rot you should look for rot in the core and stringers when the floor is done.

Now as for the top deck.. It has structural charactistics but keep in mind it's riveted to the hull. The top deck only may stop some hull flex, small cracks won't make your boat unsafe

If you don't find visable rot have fun....

Now if want to have lots of fun repower that thing with a V8.... <HR></BLOCKQUOTE>

What would I have to do to the drive if I ever did decide to put a small block V8 in it? It has an Alpha One drive and a stainless prop. Would I have to replace these also or would they hold up to the extra power. The 3.7 that's in it has 185 HP @4600rpm. Would I lose a lot of fuel economy, because it's pretty good right now with the 4 cylinder Merc.

Vic

 

[Chris]

Keep in mind when we were discussing safety in that other thread, we were discussing the dangers of using a boat that had an obviously soggy transom. And we were referencing some threads and instances of some older Hydrostreams that had blown apart on some of our friends over at Scream and Fly. Those Hydros, were also clipping along close to 100 MPH when they delaminated and then "blew apart" as I recall.

IMO, running at that speed in ANY boat, has its inherit dangers. I'm sure many of our members remember our member Bubba, who had a steering bolt break on an almost new Pulsare and it resulted in him ending up in a farmers field with a destroyed boat.

The moral of the story is the faster you go, the more careful you have to be. It's about managing the risk. That means, knowing the limitations of your boat and using proper safety equipment.

Ok, I'll get off my soapbox now.

 

[DONCONVINCER]

Changing from a 4 cyl to a V8 would involve changing everything except the drive assembly. My mistake, I was thinking the 3.7 was a V6. A V6 to V8 change would only involve exchanging the basic engine and changing the exhaust manifolds. A chevy small block and a chevy v6 use the same accessory brackets and engine mount locations. Is the engine you have what they called the 470? The drive is rated up to 260 hp and will handle about 300 w/o breaking

One thing you should check on your drive is the gimble assembly. Old Alpha drives had a splined tiller shaft. Check your drive, if it has 2 bolts on either side of the top of the gimble ring at the upper steering pivot the tiller shaft it has been updated. If the tiller has a round shaft on the top with no bolts you should have it checked for wear. The gimble ring can wear and the shaft could slip causing of loss of steering.

 

[Victorious1]

Thanks for the feedback. I checked the tiller and it has been updated, but, very glad you mentioned it just in case.

Originally this boat had a 470 or 480(can't recall axactly) and was later repowered with the 3.7/Alpha One Merc. It's amazing how well this 4 banger pushes this boat along. To me, first time out with it, I felt like I was in a rocket ship. I can just imagine what you guys must experience with boats that can do 100 MPH.

Vic