Outboard for 15-footer

A conversation among Whalers
Caseycjones
Posts: 3
Joined: Tue Mar 12, 2019 6:04 pm

Outboard for 15-footer

Postby Caseycjones » Wed Mar 20, 2019 9:44 pm

I may buy a Yamaha 75c. Is this engine good for a 1976 15-footer?

The [peak cylinder pressure reading] on all cylinders is 100-PSI; is that a problem?
Down the road will [these pressure readings be a] problem?

jimh
Posts: 11670
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
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Re: Outboard for 15-footer

Postby jimh » Wed Mar 20, 2019 10:23 pm

For advice on how to evaluate readings of cylinder pressure see

Assessing Used Outboard Engines
http://continuouswave.com/whaler/refere ... Check.html

I don’t know how to predict future problems that could occur with the engine under discussion based on the information you provided.

Read more about the Yamaha 75c model at

https://global.yamaha-motor.com/busines ... index.html

dgoodhue
Posts: 12
Joined: Sat Nov 07, 2015 4:09 pm

Re: Outboard for 15-footer

Postby dgoodhue » Mon Mar 25, 2019 9:16 pm

My biggest concern [in selecting an outboard engine for a 15-foot Boston Whaler] is engine weight. [Some engine only identified as a] current four-stroke-power-cycle engine weighs 353-lbs, which is more weight than I would want on a classic 15-footer.

TFrere
Posts: 43
Joined: Wed Sep 05, 2018 11:16 pm
Location: Lafayette, LA

Re: Outboard for 15-footer

Postby TFrere » Mon Mar 25, 2019 11:35 pm

If worried about the weight, consider the Yamaha F70 which is 253-lbs. An increase of 100-lbs is a lot for only an additional 5-HP.
1985 15’ Sport with Yamaha F70

jimh
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Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
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Re: Outboard for 15-footer

Postby jimh » Tue Mar 26, 2019 12:57 am

Caseycjones wrote:I may buy a Yamaha 75c.


Are you trying to refer to a Yamaha F75C?

Or to the classic two-stroke-power-cycle engine the 75c that weighs about 265-lbs?

Unless you clearly identify the engine, readers can only guess which engine you are asking for advice about.