Questions from a potential future Force owner...

[Chris73Cobia]

Hello,

I've got a '73 Cobia Trihull currently with a '77 'Rude 85 that dropped a cylinder. I've got the opportunity to grab a 1991 70HP Force for $1500 from a mechanic I trust who has just redone carbs, impeller and lower unit oil and will give me a 30 day promise of no issues. Besides running it, making sure the T/T works, compression check and an overall going over, is there anything specific I should look for ? He told me the compression is 135, 133, 135 so that's definitely good, but of course I'm going to verify.

Also, can someone tell me if this model is thru prop exhaust or cav plate exhaust?

Thanks in advance, I've read many posts here and I'm convinced that as long as it's in good shape a Force isn't a bad motor. But I'm not sure if there is more to look for that I know about.

Chris

 

[Chris73Cobia]

Re: Possible Force Owner...

Re: Possible Force Owner...

Oh another thing I was wondering... can someone tell me how this motor might be on fuel compared to a late 70s V4 Evinrude? Hopefully my 18 gallon tank will get me more than 7 miles each way

Thanks again.

 

[Frank Acampora]

Re: Questions from a potential future Force owner...

If I remember correctly, those Cobia tri-hulls were rather heavy. While the Force will be a good engine, with only three cylinders, it will not have the torque of the Rude 85. If the 85 was running well before losing a cylinder, the 70 will probably disappoint you with speed. If top speed is not a governing factor for you, then it will most likely be a good choice.

While I like Force engines, you can not argue the facts: The 85 was somewhere around 99 cubic inches and the 70 is about 75 cubes. And like the racers say: "There 'aint no substitute for cubic inches." On the other hand, you will most likely see an increase in fuel mileage at partial throttle and maybe even at full throttle- That might be iffy though since you will take longer to cover the same distance.

If the water intakes form a vertical line on each side of the leg above the gearcase torpedo, then it is thru-prop or dual exhaust. If there are four slots on each side of the torpedo just behind the prop, then it is single exhaust through the snout.

And, you do realize that if you are at all handy, rebuilding the Rude yourself is within reason. Almost as easy as a Force and only a little bit more expensive for the parts.

 

[steelespike]

Re: Questions from a potential future Force owner...

My biggest beef with the Force is parts.Sure there are parts out there if your willing to look enough.But pick some routine parts for the Force and say a similar Johnson/Evinrude look here at iboats.Try to figure out if the few parts you find fit your motor.I think you will find its no contest.
Then add in the many well established E/J dealers within an easy drive.
Some of those routine parts you can get down the street at your local NAPA auto parts.

 

[Chris73Cobia]

Re: Questions from a potential future Force owner...

Thanks guys, I appreciate the input, for me the fact that the Rude is a 77 is enough. My boat is a 15-footer and the plate says 70HP max. I figure the weight loss from the 310# rude might be good for fuel economy too. As far as speed the GPS says the rude in top form got me up to 33 MPH with a 12-3/4x21 SS prop, the 13x17 aluminum planed out alot faster, but was alot slower (probably about 28). My dad has a new tracker pro team with 50HP 4 stroke and I beat him to plane by a mile, but as soon as he planed out he was gone (top speed around 38). But honestly as long as I can plane out at 3/4 throttle I'm just fine (with whale tale the rude planed the boat at 13 MPH which by my calculation is top speed for a 30-35HP).

I appreciate everyone's answers, I'm sure there will be more questions...in this forum if I get the force, other section if i do anything with the Rude.


If anyone is interested I'm going to be selling the Rude pretty darn cheap. Only 1 cylinder actually has a problem (pulled the heads today) There is a chip on the edge of the piston on jug 1, but the bore is smooth. You can email me if you like, I'm just outside of Charlotte NC.