Cheeckmate Diplomat

[Mark]

I have a 1985 Diplomat 16.5 ft with a 115 in-line 6 Merc. I'm turning a 19 pitch Ballistic prop @5600rpm and showing 50 mph on the GPS. I'm going to repower next spring and want something quieter. I don't think I want the expense or weight of a 4-stroke. What do you think of a used 130 Yamaha. What would I need for a prop and what kind of top end should I expect? Is there a better choice? I'm not sure I need a V-6, what do guys think?
Thanks
Mark

 

[175checkmate]

A 130 would give you a little more speed and a better holesohot. The checkmates we all love are real bow heavy. Setback and proper set up is the key to making them go. I have a 16.5' tri-mate with a 200hp V-6 Top speed for now is 68.9 on gps.
Do you have a jackplate?
I'm running a 25P laser2. Good bow lifting prop. Turning it 5600 rpm. Going to add a pad and 5" of setback to help with top end.
What is the boat rated for?

1975 Checkmate Tri-mate 2, 2.4 200+

 

[Chris]

I hear the Yamaha motors are really nice but when they do break the parts are really expensive.

 

[Mark]

I have no jackplate and wasn't really planning on one. The boat is rated for a 140hp and you're right it loves to be trimmed to get the bow up. I've seen them with 150 and 175 V-6's but I'm tired of this howling L-6 and would like something my wife can drive easily as well.

 

[Chris]

Mark...I have a Merc XR4...and it's pretty quiet.

When you open it up, it's louder...but when your cruising it's good.

 

[175checkmate]

Mark, A jack plate would help out alot. If I trim my motor all the way down and go wot. I can hit about 57mph. Raise th motor all the way up ( no low water pick-ups installed) I gain a little better than 10 mph. The boat drives much better with out all the drag from the lower unit. Also you may want to look in to a different prop. THe balistic is not known to be a good bow lifting prop. I have a 4 blade ballistic and I have trouble getting the bow up. If you have to trim the engine up to much it creates drag. In this postion the motor is trying to push the back of the boat down, in turn raising the bow.
I installed the laser 2 and it was like driving a different boat.

1975 Checkmate Tri-mate 2, 2.4 200+

 

[Shameless]

Mark, I also have an 85 Diplomat with an Evnirude 120 with 5.5 inches of setback. I run the cavitation plate about 3.5 inches above the pad with 22-24psi of water with no holes plugged on the pick-up. I am spinning a 24 Raker @ 6000 rpm's when the water is cool and Around 70 degrees. With these conditions, I can run consistantly 62-63 on gps with my wife, cooler, and full of fuel. At 90 degrees and 85 degree water, I drop to 59mph. My best run is 68mph with light fuel, and no wife and man was that fun. Th 68 felt good too! Check the bootom of the boat also for a hook, mine had a slight one that I took out. My boat "flies" very high, I could get it even higher if the motor did not have a trim limit on it. With the bow pointed high, the prop shaft still stays horozontal too. All this out of a little 120 hp. Bob's Machine shop has some great bolt on's to add performance to just about any outboard.

 

[Chris]

Thanks Bill. /infopop/emoticons/icon_smile.gif

Welcome to the board. /infopop/emoticons/icon_smile.gif

 

[175checkmate]

Welcome to the board Bill. Do you have any pictures of your boat. Sounds like you have hit the set-up perfect on your boat, runs good.

1975 Checkmate Tri-mate 2, 2.4 200+

 

[Mark]

You guys may be providing me more questions than answers. Help me out here.
1) I thought the whole idea of a Ballistic prop was high rake equals high lift. What are better choices?
2) How does one take the hook out of a hull without wreaking the gelcoat? Is there a web site somewhere that describes it in detail?
3) How do jackplates effect ski towing performance and prop blowout during sharp turns (mine is prone to this unless I excellerate through the turn)? We ski and wakeboard so top end is not my only concern.
4) Does a Diplomat have a problem with porpoising, like the Enticer does, if the motor is bigger or with more setback?
Thanks

 

[BayviewRick]

To get the hook out, your "blue printing" your hull. Get a 8' straight edge, hold it on the bottom, this will determine the amount of hook you have. In a perfect world, you'd like to get the hook completely out. If it's a 1/16th or less you can "possibly" sand it out without going into the gel, if it's more, your going to be filling in. Basically all your doing is sanding and filling.. be patient, this is going to take some time to do right... We are going to be doing this to a Fountain 270 Fever fairly soon, even though it's a Fountain, I'll take pics and post them on here so you can see the progress. Jackplates are adjustable, for skiing and wakeboarding you can actually lower your drive allowing a better hole shot, better conrol at the slower speed/getting your skier out of the water. For speed, raise it, get the gear case out of the water, etc. A water pressure gauge is not a bad idea, a low water pick up may also be needed. You don't want to loose water pressure, bad things happen! What year Yamaha are you looking at? I'll send you an e-mail. Rick

www.Bayviewmarinecenter.com

 

[175checkmate]

The ballistic prop was made to try and be all things a high rake near the hub and a cleaver (surfacing) prop near the leading edge. I have a 27p 4 blade that has great hole shot and good top end but the handling of the boat is very bad. I installed the 25P laser 2 and it acted like a totaly different boat. I also ski,wakeboard and kneeboard. I have a hyd plate and have found that it stays in the raised postion except on the trailer. The plate is at its limits now and when the boat is put back together I will be also adding a 5" setback jackplate to the hyd one for more lift.
Cavitaion of the prop is normaly cured by triming the motor back in for a turn or take off.

1975 Checkmate Tri-mate 2, 2.4 200+

 

[Mark]

A 2000 Yamaha 130 for about $6500 CAN. Looking forward to the pics of blueprinting. Thanks.

 

[JW]

From what I've seen over the years, a Laser II is a great prop for the shorter Checkmates and the Tempest Plus is a great prop for the 20' and above Checkmates. The Trophy Plus 4-blade is a great compromise prop, better power and only giving up a couple MPH on the top end. Back in the day, the Mach brand props worked real well on Checkmate style hulls, but they aren't made any longer. There are supposed to be some new ones still available, but you have to get lucky to find one.

1995 2100BR/1995 225 Promax/23" Tempest

 

[175checkmate]

Thanks JW, I could not for the life of me remember the name of the prop for larger c-mates.
Tempest Plus and does'nt the trophy work fairly well also?

1975 Checkmate Tri-mate 2, 2.4 200+

 

[JW]

I mentioned Trophy Plus and Tempest Plus, but the older regular Trophy and Tempest work real well too. I have a 23" Tempest on mine, and it carries the bow real well. I was able to do a direct comparo one day, as I also own a 23" Laser II. With my 225 power and higher rpms, there was some noticeable difference in the seat of the pants between the two. The Tempest is a larger diameter prop, and has more 'grab'. I could feel/hear less prop slippage running my Tempest compared to my Laser II. On a smaller 'Mate though, the Laser II will be faster because the blades are thinner and the smaller diameter allows the lower horse outboards to spin up to rpm easier.

1995 2100BR/1995 225 Promax/23" Tempest

 

[Chris]

I can tell you one prop not to get. The high five! It might be great on some boats, but not on mine. It cavitates all the time. I can be completely trimmed down going around 25-30 enter a gentle turn pulling a skier and it cavitates. I talked to the guys at Pride of Muskoka Marine about it...and they basically said, yup the high five sucks on a Checkmate. /infopop/emoticons/icon_mad.gif

 

[JW]

the High 5 worked great on my I/O Persuader. I had a 21" that worked real well for pulling skiers, but then that was a heavy deep boat too, and the prop was buried of course.

1995 2100BR/1995 225 Promax/23" Tempest

 

[Chris]

Yeah, I could see on an I/O it might be alright. I meant it sucked more on the outboard models as did the guys at Pride of Muskoka.

 

[Shameless]

Sorry I missed out on the discussion the past few days, have been working with banks on my new Checkmate Bayview Marine in Green Bay WI will have built for me. If my Diplomat sound appealing to anyone, Rick is taking it in on trade and will have it in his posession on Dec. 7th. I will miss the little rocket, but no room or time for two boats and I hate to see her collect dust. A word of advice on setting up your outboard Checkmates. Take your time. A jackplate is a must although hydraulic is not necessary although convenient. When you raise or lower your height, work in 1/8 of an inch increments. It took me three monthes to dial in my boat. I do not recommend low water pick-ups on Checkmate. They do not like the hydrodynamic change and will slow down and no one should be running a cleaver to require such high engine heights. If you plug the top hole on your pick-up, be sure not to block the passage inside the gearcase, you will be fine. Invest the 50.00 buck and put in a water pressure gauge also, it only takes about 30 min to install. Also, if you have never altered fiberglass or bottom of boats in anyway, do not attempt to blueprint the bottom of your own boat. Also, it is very common with all kinds of race boats to sand the bottom of the boat to break the suction from the water. I did it with mine and I did it with all of my boats I used to race, nobody ever looks at the bottom of the boat and if done right it just makes the bottom of the boats dull. This is also only done to about the last five feet or so of the boat, depending on the lenght of the running surface. Also on props, I recommend you try at least two of the same type and pitch, because unless it is lab finished, they are never the same. I came across a 22 raker that soun more rps than 20 rakers. You also need to consider the weather and water temps when dialing the boat in. If you really want to get technical, you can find out the density of the water for the amount of slip yopur prop will get.