Opinions needed using a CMC PT 130 with a 140 HP

[Watermann]

I had this question in my restore thread for my 18' 1979 V5 Starcraft SS. I have a 1979 Merc 140 HP TOP which is what the boat is rated for. The old TnT system on the motor is a remote mounted pump with 4 lines to the rams. The 4 lines are deteriorated and would need replaced at an average of $60 ea and I have no idea if the pump or rams need rebuilt or replaced.

So I decided to pick up a used CMC PT130 rated for 130 HP that also had the clamp on type motor kit for it for about the cost of 2 new lines. I have experience with the PT130 finding it well made of 1/2" extruded aluminum with huge 9/16" diameter stainless bolt hinges. The Electric Hydraulic Actuator is rated at 7853 lbs. of thrust.

The 140 Merc weighs in at 290 Lbs without the rams and to compare a Yamaha 4 Stroke 130 HP weighs 348 Lbs so I know weight won't be an issue for the CMC. Next concern is the HP rating, the 140 is rated at the flywheel and the Yamaha at the prop. I know it's been hashed over many times here and elsewhere about how much HP a motor actually has.

Another plus is that the CMC unit will bolt on with the standard BIA pattern. Before taking the step to drill out the holes and bolt on the CMC unit I wanted to ask for you guys opinion on this. Oh and I asked CMC and they wouldn't recommend it which is what I expected from them.

For those who haven't seen my thread and want to see what I have going here's a few pics. Thanks for taking a look.

 

[ezmobee]

In my opinion you'd be well within the margin of error on the rating. I'd use it.

 

[Watermann]

In my opinion you'd be well within the margin of error on the rating. I'd use it.

Thanks for the reply ez, I think they would have to overbuild such a device for longevity if nothing else.

 

[boobie]

They are good units. I've installed a few of them and had good luck with them.

 

[Watermann]

:bump: Anyone else care to chime in with their opinion?

 

[GA_Boater]

For what it's worth - I would use A CMC 130 with a TOP 140 Merc. 10 horses is diddly-squat and the unit has a margin of reliability built into it regardless of prop or crank HP.

 

[Watermann]

Thanks GA, I got the unit mounted today and I'll post again with how the unit functions if someday down the road another iboats boater wants to know the outcome.

 

[Sea Rider]

Why was the OB not bolted straight on transom ? Would off setting the OB weight aft turn into a unbalance problem up front to have into consideration ?

Happy Boating

 

[Watermann]

Why was the OB not bolted straight on transom ? Would off setting the OB weight aft turn into a unbalance problem up front to have into consideration ?

Happy Boating

I thought my initial post covered why I wanted to use the CMC TnT. Cost of replacing old ram lines and the unknown health factor of the rams / pump. Also the bolt hole pattern is not the BIA standard on the 79 Merc.

On your second question, it's more accurate to describe it as 'set back' rather than "off set". The set back is only 6" when compared to a OB pod that isn't much but it does have value as the motor runs in the cleaner water pillow with less water disturbance. The CMC unit also allows for negative tuck. As far as weight balance the front of the boat is 18', will have 2 deep cycle batteries and a TM up front and the Merc motor only weighs 290 lbs. I have same unit on my 16' SN SS160 and have no negative issues with it at all after 3 years.

 

[Watermann]

To add to this thread about the CMC PT130 with a 140 Merc, it works perfectly with no issues other than of you go in reverse with the motor negative tucked all the way in it will create a bulge of water that feeds back into the splashwell.

 

[ondarvr]

It's good of you to update this thread with the results.

Thank you

 

[jimmbo]

Man I love those inline 6s
I got news for ya, your engine or at least the cowl decal is newer than a 1979. I would guess a 1980

 

[Watermann]

You are correct sir, I debated for some time over putting on the original 79 decals and the 80s after repainting. I got the 80 repops, just liked how they looked.