Mercruiser Bluewaters with Velvet drives.

[fishmen111]

Looking at a restored 1991 Thompson 288 flying bridge with twin 5.7 Mercruiser Bluewaters and Velvet drives. I have never had an inboard and am wondering if there is any thing much different than an I/O to look out for. They are un-rebuilt low hour (<400) raw water cooled units slipped in brackish water their whole life. Boat was hauled and inspected last year with only the bottom being painted and the shafts sealed. All water pumps, manifolds and fuel system components have been replaced. Engines run flawlessly with excellent oil pressure and compression is good. The temp gauges are reading higher than I like and the owner says "thats just where they run". We will go on a sea trail next week and I am going to put a thermal gun on them. Where should I aim it and what should it read? 160 at the thermostat housing? The stringers are solid, but there are two cross members running up to the engine box stringer section that I will need to replace. The seller has a 3 year old survey that rated the boat in really good overall condition relative to age. I know that I should have it re-surveyed, but it will cost $1000 to get the guy up here. The boat is only $15k with a pre-paid slip for a year ($2400). Red flags? Advise? Flames? Thanks as always guys.

 

[Don S]

Re: Mercruiser Bluewaters with Velvet drives.

The temp gauges are reading higher than I like and the owner says "thats just where they run".

What was the temp the gauges showed?

Brackish water, original exhaust manifolds and risers may means they are probably due for replacement.

 

[arks]

Re: Mercruiser Bluewaters with Velvet drives.

I have never had an inboard and am wondering if there is any thing much different than an I/O to look out for.

The engine is essentially the same as an I/O. The Mercruiser smallblock/Velvet drive is a pretty common setup. Velvet drive transmissions are OK but (like anything mechanical) need occasional maintenance. As a general rule, inboard drivetrains are more reliable than I/O because they have fewer parts exposed to the water.

The temp gauges are reading higher than I like and the owner says "thats just where they run". We will go on a sea trail next week and I am going to put a thermal gun on them. Where should I aim it and what should it read? 160 at the thermostat housing?

After a full warm-up (and with the boat on plane at a steady speed), start measurements on the exhaust manifolds near the engine block at each exhaust port. At this position any reading above 170 could indicate a pump problem or manifold blockage. From there, move up the manifolds, taking a new reading about every 6". As you get farther from the block the readings should go down somewhat. NOTE: any spot that measures significantly higher than an adjacent port could indicate a blockage. Also look for rust streaks on the block or manifolds- that could indicate a crack or pinhole.
If you find some inconsistencies but otherwise the boat performs well, it could be a relitively minor fix- a new impeller or maybe a set of manifolds. This can be used as a negotiation tool.

I know that I should have it re-surveyed, but it will cost $1000 to get the guy up here.

GET A NEW SURVEY. Use a local guy that is NOT recommended by the seller or his salesman- at the going rate you'll spend about $500 for a complete pre-purchase survey (dry and wet survey as well as a sea trial). Your insurance company will require a survey before they'll insure it anyway....

Red flags?

Poor resale value in Thompsons.They were built with encapsulated wood. I've seen a number of them literally fall apart. This is yet another reason to have it surveyed. A competent surveyor will know how to measure the hull and stringers for moisture. Any readings above 17% is excessive and will require work. If the vessels bilge has been kept dry its entire life then it'll probably be OK.
Just my opinion.

 

[fishmen111]

Re: Mercruiser Bluewaters with Velvet drives.

What was the temp the gauges showed?

Brackish water, original exhaust manifolds and risers may means they are probably due for replacement.

Gauges were reading about 3/4 at idle. Would come down a little when throttling up. There are no reference numbers on the gauges, just hashmarks. Manifolds appear to be newer.

 

[fishmen111]

Re: Mercruiser Bluewaters with Velvet drives.

GET A NEW SURVEY. Use a local guy that is NOT recommended by the seller or his salesman- at the going rate you'll spend about $500 for a complete pre-purchase survey (dry and wet survey as well as a sea trial). Your insurance company will require a survey before they'll insure it anyway....

Found a local guy. Hope to get this done next week.

 

[Fireman431]

Re: Mercruiser Bluewaters with Velvet drives.

I have 7.4L Merc's with Velvet drives. Been very loyal with minimal maintenance.

When the survey is scheduled, they'll probably ask if you want a mechanical survey as well. That is compression testing the engines and getting oil samples for analysis. Usually runs $150.00 per engine. It's worthwhile for peace of mind, but I'd stay and watch them to make sure it's done. Some are pencil-whipped and you get nothing for your money.

 

[arks]

Re: Mercruiser Bluewaters with Velvet drives.

Found a local guy. Hope to get this done next week.

Trust me, it will be money well spent. Try to be present when the survey is performed- you'll learn a LOT about the boat, even if you've been around them your whole life. You and the seller will have to figure out the details about launching and/or hauling for the survey. The buyer usually pays but (of course) everything's negotiable. Have the seller operate the boat during sea trail- the surveyor won't (or at least he shouldn't). He'll be busy checking the mechanicals and reading gauges.
As we all know- like it or not- buying a boat is a very emotional thing. Be prepared for a negative report- you are paying the surveyor to be critical and look past the shine. If he finds a major problem you need to be mentally prepared to negotiate the problem to an acceptable solution or just walk away. There are tons of boats for sale out there!

If you end up not buying the boat due to a problem uncovered during the survey, remember that the survey probably saved you much more than the 500 bucks. I know because it happened to me.
Good luck.

 

[fishmen111]

Re: Mercruiser Bluewaters with Velvet drives.

Thanks a bunch. I have had many boats, but never one of this size that is not trailerable. Ironically, I normally buy boats with blown motors or drives just because I love working on them. This is new to me. The novelty of having a cheap house on the water and the fact that he just paid the yearly slip fee in an area where slips are long gone, did make us want to jump on it yesterday. My initial logic was why spend $500-1000 on a boat that is only going to cost $12,700 after subtracting the slip fee. Will update you after the survey.

 

[Fireman431]

Re: Mercruiser Bluewaters with Velvet drives.

Spending $500-1000 is a deal if you get taken a bad business deal. Something that looks great may have hidden water damage or rotted stringers. Once in a sling, checking the hull for damages may save you 2-3000thousand dollars in repairs.

Good luck...