Choosing which Johnson 48 to keep

[Johnson44]

I have a '94 and a '93 Johnson 48 HP, both are on one boat, tilt and trim on each, remote controls, electric start. I plan to use only one motor on the boat next spring (moved back to center on the transom naturally). Both run OK except for minor idle issues. Intuitilvely, one would keep the newer and sell the older.
I suspect the older may have a few more hours but no way to find out for sure. How do I choose which motor to keep?

 

[oldcatamount]

Re: Choosing which Johnson 48 to keep

sounds like a coin toss to me, unless you know for sure that one motor has lots more use than the other or has been abused in the past.

 

[Al-53]

Re: Choosing which Johnson 48 to keep

keep the best one and send me the other one...lol......been looking for something like a 50 for my boat

Al

 

[JB]

Re: Choosing which Johnson 48 to keep

Put one on a stand in the garage and the other on the vessel.

Having a spare that is a plug and play replacement is priceless.

 

[DJ]

Re: Choosing which Johnson 48 to keep

Put one on a stand in the garage and the other on the vessel.

Having a spare that is a plug and play replacement is priceless.

Good advice-PLUS. Check the compression of both. That will tell you which one is healthiest.

 

[Johnson44]

Re: Choosing which Johnson 48 to keep

OK, the 1994 48 HP motor has 120 and 130 compression upper and lower cylinder.
The 1993 48 HP motor has 135 and 140 compression upper and lower cylinder.
Is that enough difference to justify using the 93 and keeping the 94 as backup? Or everything else being equal is it a toss up? I suspect both motors have nearly the same hours, the 93 maybe slightly more hours but very little difference in hours.

 

[trendsetter240]

Re: Choosing which Johnson 48 to keep

OK, the 1994 48 HP motor has 120 and 130 compression upper and lower cylinder.
The 1993 48 HP motor has 135 and 140 compression upper and lower cylinder.
Is that enough difference to justify using the 93 and keeping the 94 as backup? Or everything else being equal is it a toss up? I suspect both motors have nearly the same hours, the 93 maybe slightly more hours but very little difference in hours.

I'd run the 93 just because the compression is slightly higher. Likely means more life left in the rings.

Either way, they are identical except for the year. All parts are interchangeable and keeping one as a spare is an excellent choice.

As for your idle issues, take the opportunity to clean the carbs thoroughly over the winter and you may find that issue is gone in the spring. Also remember to change the leg gear oil and impeller.

Cheers.

 

[Haffiman]

Re: Choosing which Johnson 48 to keep

The 93 seems to have a UFI ignition, the 94 the 'normal' external power pack.
The difference in the comp test MIGHT be an introduction of compression relief holes in the cylinders that makes it more easy to start and a smoother low idle, but not quite sure.
But due to ignition system alone, I would have kept the 94!!!