1977 Checkmate Trimate II Setup

[Rustalium]

Hi everyone. I have a 1977 Checkmate Trimate II that i have owned for almost 10 years. For the first 5 it had the original 77 140 Johnson, until I found a 96 150 Johnson Faststrike to hang on the back. Last summer I completely restored the interior, replaced the carpet, replaced about half of the rotten floor and had the deck redone. My long going problem is chimewalking! Everytime I hit 60mph it starts a rocking. The faster I go the worse it get until it becomes so violent that I no longer want to try and drive through it. Ive read a couple posts that said a jackplate helped but none were on my model.

So here is what i got:

1977 16'3" Checkmate Trimate II
1996 150 Johnson Faststrike (no mods)
Pulling a 24 pitch Raker
Motor is high as possible on the transom (Prop shaft is 7" below bottom of boat)
Best run so far is 62.8 mph at 5400 rpms (gps speed) had to have 2 people in bow seats to get that speed.
I also still have single pole steering that is good and tight but I am considering changing over to hydraulic.

My question is how much of a setback do I need and what should be my prop shaft hight. Will this help get rid of my chime walking or will it just be a faster walk in the park. Also do I need a low water pickup (I have a water pressure guage). And should I brace the transom with anything to help with the jackplate. What size prop should i pull, maybe a 26 pitch raker or would a different style prop help me better?

I think thats about everything. Any and all comments and recommendations welcome.

[bigdave]

Checkmate's love trim. the thing is your motor is too low. most c-mates like the prop about 3"below the bottom.

First thing is get a hydraulic plate w/ atleast 6 inches of setback.

Jack it untill pressure drops then come back down slightly. then start trimming.
takes a few minutes to get it all set, but well worth it.

we had a 1980 Checkmate Diplomat with a 92 johnson 140 (2.0 loopcharged)
before the jack plate would chine walk so bad you thought the boat was going to flip
After a 6 inch cmc hyd jack plate, no more chine walk. gained over 10 mph.
we were running a 22 raker at 6300 rpm and I think it would have gone faster but we could not afford to keep buying props at that time.

[Rustalium]

Thanks for the info. So do you think that 6" is enough setback or should I look at a 10"? Also do you think I will need a low water pickup?

Thanks again

[tdogcarter]

First off, you need either dual cable or hydraulic steering. Next you need solid motor mounts. Then from there you need to make sure the transom is not flexing. From there you need to make sure the boat is set up so either something has weight to the passenger side. Either shifting the gas tank over or changing the battery to the other side.
I had a 1979 Trimate II with a Mariner 200 hp Bob's 5 - 1 Jack Plate and Sea Star Pro Hydraulic Steering. Obviously Solid motor mounts.

The hull has a top speed of about 85 mph. I hit a best of like 82 or 83 on gps but you have to really fight it keeping it on the small v part of the hull. It will chine even still you just have to learn how to drive it and correct it from happening.

The transom from the factory is plenty strong if you are mounting any engine to the transom, but with the 5.5" of setback and the 200 + hp V6 it did need some strengthening to be able to not flex so much that would cause ill handling.

The best prop I found was a 26 trophy or a 28 chopper because the boat still needs some bow lift with only 5.5" of setback. I would not go to much more than 6" of setback unless you plan on beefing up the transom. 8" max with a beefed up transom.

The trimate is not made for a speed demon, if you were to put a pad on the boat it would be an 90 mph boat with 200 + hp

I had the boat for 3 years and it was a very nice boat for 6 - 7 adults to go out and play on the water.

Trey

[Rustalium]

Found a good deal on a 10" CMC Hydralic Jack Plate. Has anyone ever tried this much setback on this type of boat... Will it be too much?

[175checkmate]

10" Would be to much. I would stick with 5-6"
Mine would walk real bad with the prop shaft at its lowest point. Jacked the motor up to the 3" range and the chim walk was gone. I added a pad to the bottom of my boat, should be easer to balance on the pad then on the point of the V. I am going with a 6" hyd CMC.
Install a water pressure gage, duel cable steering and jack the motor up. It will run a ton better.