1979 15HP Johnson VS 1988 15HP Johnson

[Shootit]

Hi guys first post on here after discovering and joining this very informative site.

I currently own a 1979 15HP Johnson in V good condition and which runs well and is reliable on a 3.2M RIB.

I have the chance to buy a 1988 15HP Johnson which is in excellent condition and recently serviced with good compressions.

My question is am i right in thinking the 79 was rated at the flywheel and that the 88 will be prop rated and if so would i notice any difference in power between the 2 motors?

Thanks
Adrian

 

[whalerfreak22]

Re: 1979 15HP Johnson VS 1988 15HP Johnson

I say buy that motor they are the same hp just different years.

 

[Rick.]

Re: 1979 15HP Johnson VS 1988 15HP Johnson

I really doubt if you would be able to notice any difference in the two performance wise. The 88 I'm pretty sure will have a cable tiller system which has to be an improvement over the older gear system in your 79 but that's not a good enough reason to abandon your 79 (IMO). Your only moving up nine years and unless you can see a good reason stick with the motor you know would be my advice. Either way, best of luck. Rick.

 

[Shootit]

Re: 1979 15HP Johnson VS 1988 15HP Johnson

Ok 2 different opinions to start with that always makes things interesting
Are the motors identical in terms of powerheads/carbs etc and if not what about fuel consumption as well?

 

[jasper60103]

Re: 1979 15HP Johnson VS 1988 15HP Johnson

Ok 2 different opinions to start with that always makes things interesting
Are the motors identical in terms of powerheads/carbs etc and if not what about fuel consumption as well?

You can compare parts here...

http://shop2.evinrude.com/Index.aspx?s1=c97c4e09b4e7f1504e445dc681d3aba2&catalog_id=0&siteid=1

 

[ChrisAG]

Re: 1979 15HP Johnson VS 1988 15HP Johnson

My question is am i right in thinking the 79 was rated at the flywheel and that the 88 will be prop rated and if so would i notice any difference in power between the 2 motors?

You are correct, and I think you will notice a slight difference, especially when the boat is heavily loaded. From the 1981 brochure, they claimed improved torque & efficiency from a tuned exhaust, adjustments to compression ratio, and timing. They said something like "23% faster when the boat was loaded with two men and their gear," i.e. I'm guessing 500 lbs. There would probably be less of a difference when the boat was lightly loaded.

From 1981 on the 15's power rating was 500 rpm higher, with the top of the full-throttle operating range moved up from 6500 to 7000.

At some point they also moved the thermostat from the bottom of the block to the top, making for easy replacement. And other refinements, such as the cable throttle as previously mentioned.

I think you should buy it. Then (making sure both motors are in decent tune) report back your results.