used spare outboard

[luisdiaz]

Hi everyone. Am thinking to buy a spare outboard for my Palm Beach 173 white cap 2001. This hull weight 1375 pounds. I usually do fishing with my 3 sons and that should be no more than 600 pounds of us. Am actually using a johnson 70hp 2001 (thinking to change it to a 90hp). I think got a good deal on a yamaha 9.9, 2002. The main purpose of it would be to use it in case main motor fails. The second purpose (and don't know if am right or wrong) is to use it as a trolling motor. I do fishing at sea. Happens that have a side imaging fish finder and the turbulence of the main motor is bothering that side. (Am also working out other ways to attack this problem)
Got some questions
1. Is that yamaha too big or too small for this aplication?
2. I checked the manual for yamaha up to 1996 and it says yamaha wont publish specs for cylinder compression. Any body has an idea what would be close to good? It says the important thing is the difference between cylinders (15psi?). Top and bottom diff., but it has only two.
3. What speed should I expect to achieve? I know it depends on many factors, (wind, sea conditions. rpms,weight etc...). but a rough approx. will be fine.

Please, you remarks on any of those or all,will be appreciated.
Thanks, Luis.

 

[yamamarinetech40]

Re: used spare outboard

ok, that motor would be fine for both, but with a small(70 or 90) outboard, i would just troll with it, your preference. As far as motor interfering with fishfinder, it was installed incorrectly(transducer), in wrong place. As far as the compression, it's not 15 psi it's 15% from highest to lowest compression. And no, I've never seen published compression on small engines, but would expect on this one to be above 100 psi, doesn't matter as long as above 90 or so.

 

[luisdiaz]

Re: used spare outboard

The motor compression is fine, over 100 and close between 10 psi difference between the two cylinders. I have heard some opinions and agree with you that does not make much sense to use it as a trolling and that will be kind of a pain to use it as a spare.
Happens that this transducer is a side imaging and the turbulence of the motor is seen as noise on the motor side. It may be to high. I will try to lower it and test again.
Thanks for your post.
Luis.

 

[sdsaw]

Re: used spare outboard

I have that same motor on my 22' aluminum cuddy.
I can go as fast as 5 mph with it.
Works good for trolling speeds between 1-3 mph. Any faster, use the main motor.
I feel that a kicker adds more safety if you lose your main power.
It won't get you there fast, but at least you'll be going in the right direction!