Questions for the experts!

[toast]

I have very much enjoyed this forum, there is a ton of great info!!

I have recently been contemplating the purchase of a 83 18 foot diplomat with 87 mercury blackmax 150. I am fairly new to boating, but I do know the basics having grown up with a boat in my family. I really like the looks of this boat and I think the performance suits my personality! What I am really asking is there anything I need to look for before I hand over my money. The motor runs great and has had a compression test that came out fine. The interior was restored about a year ago, Could have been done better but it will do for a couple years. The prop on this boat is a SS 3 blade @ a 19 pitch. Comments on the prop would be appreciated, I think that will be the first thing I change! It has a manual jackplate. The current owner said he can get it 55 to 60 mph depending on conditions. With this motor is mid 60s possible? Asking price is $3500.

any comments would be appreciated! I would like to purchase it before the 1st of the year.

It has also has a new paint job that looks great! But want to make sure it sticks on the boat!

I am lookin forward to participating in this forum, what a great asset it is. I will send the picks as soon as I get them!!

 

[Chris]

Welcome to the board Toast!

~~~~~~~~~~~~~~~~~~~~~~~~~~
Webmaster
Checkmate-Boats.com-The Fanatics Home!

 

[Shameless]

Toast
Welcome to the forum! I will try to help with some perf qustions on the diplomat. My number one recommendation is call Mike Combs at Checkmate and he can give you the best info where to start. You need to find out wht the rpm's are at WOT. That is the primary way to size the pitch of the new prop. A 19p sounds to small. I assume you have about 6 inches of setback. If that is the case, you want to start with the cavitation plate 3 inches above the pad. Very important, does it have a water pressure guage? If not, install one, they are cheap insurance. I also had a manuel plate. The best way to measure the height of the motor is to take a 6 foot strait edge and a 2-3 foot level. First, make sure the boat is level, then make sure the prop shaft is level. Take the straight edge and run it from the pad out past the back of the boat, fae enough out to use the cavitation plate to measure. Then measure from the top of the staright edge to the underside of the cavitation plate. Like I said, you should start a 3 inches, then move up in 1/8 of an inch increments until you get the desired performance with rpm and speed. The higher you go, the more rpm's you will turn and the less water pressure you will get, that is why it is so important to have a pressure guage so you do not over heat. How was the speed measured, gps or speedo. Speedo's are not accurate, generally they will show about 5mph faster than actual speed. Can you run 65? You should be able to run 60 on GPS and 65 on speedo to start. I do not see any reason why you can't bump those up 5mph when you get a feel for the boat and where it likes to be set up. Also, you should goto Bob's Machine Shop, on their web site, there are some good, inexpensive bolt on performance goodies, of course inexpensive is relative.
Merry X-mas!
Bill

 

[toast]

thanks for the input!! Does this price seem fair for this boat?

 

[BayviewRick]

Toast...welcome to the board! The Checkmate Diplomat is a great boat, all out blast to run! Some things to look for. Checkmates Gel work is superior to practically all other brands, i've seen mid 80's boats look flawless, you stated this one was painted, look for signs of damage, was it just faded, or painted for a reason. Crawl underneath, look for signs of repair work, signs of blisters. It also doesn't hurt to have the engine checked, compression,leak down testing. This is no gaurantee, but, it will give you an idea of what kind of condition the engine is in. $3,500 for a Diplomat... sweet price, I'm at home, don't have my books here.. but most book in the low to mid 5's. Rick

www.Bayviewmarinecenter.com

 

[175checkmate]

Look as deep inside as the owner will let you. Great looking on the outside and could be full of rot on the inside. ( Look at my tri-mate 2 for an example).

Things to check.
Transom. With the motor trimed up a bit on the trailer and the trailer secured so the front won't jump up. Stand on the motor and bounce. The transom sould not flex or move at all. If it does it has rot.
Look at the drain plug and anyother thing bolted to the transom. This includes the engine mounting bolts. Look for discolation. This is also bad.
Look at the bottom of the hull. Noting any cracks and chip, what you are looking for are stress cracks. For checkamtes to have these the boat was used very hard in rough water. Checkmates are strong and well built but used the wrong way even the great ones fall.
After going all over the outside now move to the inside.
Look at the inside of the transom. Move the batt. out of the way and get up close and personal. Look at the engine mounting bolts. Are they starting to sink into the transom. This is bad, wood is starting to rott under it.
Look under the splashwell and sides, looking for fiberglass cracks and signs of delamination ( wood and fiberglass seperation).
Pull up the corners of the carpet (if owner will let you) look at the floor. Is it sealed in fiberglass. If not this is bad, should be incased in glass.
Look at the upolstry. All the coushion wood should be glassed or it won't last.
Heed caution if the owner has trouble with this.
As far as the motor goes compression and leak down tests are a must. Go for a test drive. Idling on the trailer will not tell all. (been there, got the new powerhead to prove it)
Bring 2qt of lower unit oil and a clean drain pan, drain the oil, look for water and metal.
$6 of oil could save you $1000 in a new or rebuilt lower unit.

Now the fun part. Depending on you mechanical ability and fiberglass knowledge level.
Transom rott. If you have it done $1500-4000
Do it your self, $250-750 depending on what you want to do.
Interior, you call the sky is the limit.

Looking at the above discription. If the motor is good. You get recoup your losses from just the engine. If things turn bad. You are basicly buying the engine and getting a boat and trailer for free.

If the boat does have rot, exsplain this to the seller and what in cost to fix and this turns in to a great barginaing tool. And you have a winter project.

This is not intended to instill fear. I have my trimate torn apart all wood removed and am rebuilding it.

Keep us posted. And good luck.

Oh and welcome to the board.

1975 Checkmate Tri-mate 2, 2.4 200+

 

[175checkmate]

Also I agree with Bill, there is speed to be had with a prop change. A water pressure gage and temp gauge is a must when running a jackplate.
But I would worry about speed later and consentrate on the condition of the boat for know.
Good luck

1975 Checkmate Tri-mate 2, 2.4 200+

 

[toast]

Thanks for the input guys! I really appreciate it. I looked closely at the transom and bottom did not see any stress, I will defenitely bounce on the motor though to look for flex in it! Had my hitch put on my truck yesterday hope to usin tomorrow! Ill keep you guys posted!!

Merry Christmas!

 

[Chris]

Good Luck Toast!

~~~~~~~~~~~~~~~~~~~~~~~~~~
Webmaster
Checkmate-Boats.com-The Fanatics Home!

 

[175checkmate]

Good luck to you, hope all turns out well, would make for a great x-mas present. THats a screaming price on the boat if all is well. Thats a good price if all is not well.

1975 Checkmate Tri-mate 2, 2.4 200+

 

[blazerman]

there is also other ways that are more accurate to judge rotten wood, take a hammer and tap the transom, prettymuch anywear and it should sound solid if theres rotten wood, it will have a lower more like a hollow sound my father and i have rebuilt lots of boats from a 40ft offbrand scarab wanna be to a 7ft wooster hellion and yes i also have a 76 trimate 2 that i have stripped down to the hull and i need info on the apulstry so if you got any info let me know

 

[blazerman]

so you know i strongly recommend only using 3M inovations fiberglass and hardener the cheapo crap wil give you trouble down the road for instance can separate from wood. finding a prop for a boat isnt really something you can look up in a book mostly 90% of older boats arent the same play with them and try them out can always send them back to michigan propeller if you dont like it

 

[Shameless]

Thw hammer is a great way to check for rotted material and a little more simple way to put it is if it oings when you hit it, it should be good, and if you get a thud, look out.

 

[toast]

I am taking it home tomorrow!! After looking at it closer, I dont think it is a diplomat. I think it is a MX-18 after looking at the brochure posted in the showroom here. When I get it home I will post some pics. This boat doesnt have a jackplate. I was thinking of getting one, but dont want to spend 1,000 bucks on it. I was thinking of a manual one, any suggestions?

 

[Craig]

Connect an ohm meter across the ski eyes on the transom. If the transom is waterlogged there will be a voltage across it.

 

[JW]

Lowest price GOOD jackplate is the CMC manual 5.5" setback jack plate. You can get it online from www.BassPro.com for $199.
Slightly up there in price (still under $300) is the Rapid Jack and the Detwiler plates. Best prices so far on those are from www.rickracers.com

1995 2100BR/1995 225 Promax/23" Tempest

 

[toast]

Well,

I took her out on Sat. afternoon, gotta love Atlanta weather it was 69 out with no wind. I hit 62 on the speedo, felt alot more like a real 56 or 57. I had a ton of chine walk while trimmed out, I am hoping when I get the jackplate in it will help this out? The previous owner had recently put a 19p SS Mercury prop on it. I am thinking I will get a new prop this week. I have already purchased The CMC manual jackplate with 5.5 inches of setback, that will be installed Thursday along with a pressure gauge. My local marina will do the installation. I am hoping weather permitting, to take it either Sat. ot Sun. Any other suggestions while I have it in the shop?

Thanks,
toast

 

[175checkmate]

What rpm where you tutning with a 19p prop. That may be alittle small. Once you starting jacking the motor up you will see an increase in rpm.
Congrats on the new boat. Can't wait to see pictures.

1975 Checkmate Tri-mate 2, 2.4 200+

 

[toast]

It was running 5600 to 5700.

I just noticed your in Waycross. Were you lucky enough to get on the water saturday? It was'nt bad at all! What hole do you run your boat on? I have mine on Allatoona.

 

[175checkmate]

Had a major glass fest on sat. Installed the top half on the bottom again so the boat is hole. Still have a bunch of work to do before I am ready for the water.

Where is Allatoona??

1975 Checkmate Tri-mate 2, 2.4 200+