1974 15hp johnson, worth fixing?

[dkonrai]

i have this 74 johnson 15hp motor. compression is great 118, 120. carb is decent. here is the problem, i have low idle issues and i think the coils (all three) are bad and leaking. when the motor is running i sometimes get shocked off the motor.
i think the motor is only worth about 300 on the used market. so, is it worth buying points, ignition coils, and the pick up coil? i m estimating the cost around 150 or so in parts. i have already rebuilt the carb, fuel pump, waterpump.
or should i part the motor out?
what would you do?
dino

 

[HighTrim]

Re: 1974 15hp johnson, worth fixing?

Doesnt sound like a motor that you would part out at all.

Are you sure it is simply not the plug wires cut/damaged, especially at contact points, giving you the shock?

Try running it at night to see if you can see the arcing

 

[dkonrai]

Re: 1974 15hp johnson, worth fixing?

coils look pretty bad

i will post a picture of the pick up coil later. it is in pretty bad shape. motor does run!
<a href="http://s374.photobucket.com/albums/oo184/dkonrai/?action=view&current=P1040541.jpg" target="_blank"><img src="http://i374.photobucket.com/albums/oo184/dkonrai/P1040541.jpg" border="0" alt="Photobucket"></a>

 

[dkonrai]

Re: 1974 15hp johnson, worth fixing?

 

[Solittle]

Re: 1974 15hp johnson, worth fixing?

Exterior looks of a coil don't mean squat. Test for good spark.

 

[82rude]

Re: 1974 15hp johnson, worth fixing?

theres no doubt the coils are bad .so for 150 or so you would have a good reliable running motor correct?cost of new 15 hp?fix it !i totally dissagre with the above post, the coils are cracking and if not allready will go all the way through causing all sorts of issues.been there, fixed it and did others also that were exactly the same.a faulty coil can still issue a good spark then fail minutes later.

 

[82rude]

Re: 1974 15hp johnson, worth fixing?

as an add on i had that exact same year motor and went through all the usual tests for a poor running motor .i wish i had of taken pics of the coils they were exact twins of yours.well the motor got 2 new coils and is still running perfectly 3 years later .my own personal theory is the cracks go deeper than it looks and moisture gets in there shorting out the coil.

 

[HighTrim]

Re: 1974 15hp johnson, worth fixing?

I agree, alot can be said about the appearance of a coil. If it is cracked, toss it.

New cracks can be sealed, but have not tried myself

 

[dkonrai]

Re: 1974 15hp johnson, worth fixing?

here is the pictures of the pick up coil

 

[dkonrai]

Re: 1974 15hp johnson, worth fixing?

on a good note, the base plate has almost no play what so ever. i have no side play at all

 

[kbait]

Re: 1974 15hp johnson, worth fixing?

Run the motor in the dark. You'll likely find a coil arcing to ground through one (or more) of the cracks. Replace 'em, or tape 'em up. I taped up a buddies coils (looked the same as yours do) so he could go out fishing that night (4 years ago..) Still runs fine. I used strategic tape-placement -threading it between the plastic and the green metal part of the coil, and covering all the plastic, cracks included.

I wouldn't replace the pick-up coil until you secure the drive coils and test-run. It may be just fine. One cylinder arcing out intermittently will immediately kill a low-idling motor..

 

[82rude]

Re: 1974 15hp johnson, worth fixing?

though i understand what your saying kbait, usually things have a way of biting you in the butt.you might get lucky as your buddy did or at a critical time the jury rigged part will let you down.personally i preferr not to take the chance as ive been on the bitten end once and that was enough for me.

 

[HighTrim]

Re: 1974 15hp johnson, worth fixing?

I have a friend that puts fibreglass and resin over the cracks and he swears by it.

 

[dkonrai]

Re: 1974 15hp johnson, worth fixing?

i wonder if liquid tape would work? so as long as i wrap the coils with something, that wont leak voltage i should be good to go? what about the pick up coil? look ok?
dino

 

[dkonrai]

Re: 1974 15hp johnson, worth fixing?

as an add on i had that exact same year motor and went through all the usual tests for a poor running motor .i wish i had of taken pics of the coils they were exact twins of yours.well the motor got 2 new coils and is still running perfectly 3 years later .my own personal theory is the cracks go deeper than it looks and moisture gets in there shorting out the coil.

would you replace the pick up coil too? my guess it is working. strange thing is it runs and seems to have high revs. it just wont idle.

 

[HighTrim]

Re: 1974 15hp johnson, worth fixing?

It wont idle likely due to the arcing coils as already mentioned

 

[dkonrai]

Re: 1974 15hp johnson, worth fixing?

It wont idle likely due to the arcing coils as already mentioned

hahaha yes sorry i got a little side tracked.... will do the wrap on the coils to see what it does or doesnt do. will post the results.
dino

 

[jmendoza]

Re: 1974 15hp johnson, worth fixing?

You can try drying out the coills in a 200F oven for an hour, then coating the coild with penetrating epoxy...or just replace them as they are cheap.

 

[dkonrai]

Re: 1974 15hp johnson, worth fixing?

i cant seem to post the link for the motor. how do i embed the video?