1976 25 hp Points question

[CharlieB]

Re: 1976 25 hp Points question

Swap the coils, run the motor, see if the bottom plug clears and the top gets dirty. Again pull the plug wires while running to see if it is now running on only the bottom.

It very well may be that the crack in the lower coil is shorting to ground.

Switching the coils should prove it.

 

[69 Alumacraft]

Re: 1976 25 hp Points question

Replaced driver coil and points and condensers and getting good spark on both leads spinning the flywheel with a ratchet!! Have ignition coil on order to replace cracked one. Took everything off armiture and cleaned w/ carb cleaner. Can't test run till tomorrow. Will keep posted. Thanks to all especially F_R, appears to have been points, condensers.

 

[samo_ott]

Re: 1976 25 hp Points question

Or you can do what I did on my '75 20hp and remove all the driver coils and external coil gobboldy gook and replace it all with good old tried and true magneto's and have it run like a charm Of course you have to have a spare mag plate and flywheel lying around to do so.

 

[69 Alumacraft]

Re: 1976 25 hp Points question

Still only running on top cylinder , I am able to get spark on tester on both but only runs on one I have a new external coil coming to replace cracked one. Hope this does the trick.

 

[RogersJetboat454]

Re: 1976 25 hp Points question

Still only running on top cylinder , I am able to get spark on tester on both but only runs on one I have a new external coil coming to replace cracked one. Hope this does the trick.

Have we done a compression test yet?

 

[69 Alumacraft]

Re: 1976 25 hp Points question

Not yet, bought a tester the other day. May try it tonight. Do I leave the plug on the cylinder I am not testing in?

 

[RogersJetboat454]

Re: 1976 25 hp Points question

Not yet, bought a tester the other day. May try it tonight. Do I leave the plug on the cylinder I am not testing in?

Disconnect the fuel line, pull both plugs, and ground both plug leads to the block. Install the tester on the cylinder to be tested, turn the throttle to WOT, and pull the cord 4-5 times. Repeat on other cylinder. Compression figures should be within 10% of each other.

 

[oldman570]

Re: 1976 25 hp Points question

If you have not replaced the wires from the points to the external coils, they might cause a problem of no fire or intermitent fire. I have had several that the insulation on the wire will let it short out where they go from the points to the outside of the stator plate. The resistance measured from the points to the coil has to be the same. On used points it is best to set them at 18 ths. rather than 20. You have to rember that these motors have maker points and not breaker points like most. In plan words they put ground to the coils until they open up. Theyare a B*&%^h to work on is you don't have a REAL good understanding of the.
Best of Luck

Oldman570

 

[69 Alumacraft]

Re: 1976 25 hp Points question

How do I ground the plug leads?

 

[RogersJetboat454]

Re: 1976 25 hp Points question

How do I ground the plug leads?

Any way you can....

Ideally a set of jumper wires with alligator clips is what most people use (you could make these your self real cheap, and will be handy in the future for other testing needs).... Or if you want to rough it, you could pull the boots back, and liberally tape the connectors to a relatively bare spot on the block.

With a points style ignition, it is not imperative that you ground the leads. Shouldn't do any damage to the ignition system with only a dozen or so pulls. If you had a CD ignition system (power pack) cranking/running the engine with open plug leads is bad news for the module, and will take them out in a short amount of time.

In general it's just good practice to ground them regardless. If anything, it prevents you from getting belted by a few thousand volts...

 

[jasper60103]

Re: 1976 25 hp Points question

How do I ground the plug leads?

Here's one way...
Stick a phillips screwdriver in the clip that goes on the plug. Lay the shaft of the screwdriver against the engine block or pan. Just make sure the surface you choose is grounded.

 

[F_R]

Re: 1976 25 hp Points question

There is another reason to ground the plug wires. Fire. As you crank the motor with plugs out, a combustable fuel/air mix blows out the plug holes. The right conditions and WHOOM!! Ask me how I know.

 

[69 Alumacraft]

Re: 1976 25 hp Points question

Compression 130 on both! Did spark test again and #1 is right on while cracked coils #2 is weak. Report back when my new coil arrives.

 

[69 Alumacraft]

Re: 1976 25 hp Points question

So, got tired of waiting for coil and did a spark test on cracked coil switched to top cylinder and guess what, it sparked a plenty so as oldman570 suggested it was the wires from the armature to coils that was bad. Next question: Instead of ordering new leads I used some 16 AWG anchor marine wire I had lying around to replace wiring from armature to coils. Now I am getting good spark on both cylinders!! But will this type of wire hold up? It seemed to match what was there perfectly. Any of you guys who are not tired of this saga and have time to chime in please do and thanks in advance.

 

[F_R]

Re: 1976 25 hp Points question

It will work for awhile, however the correct stuff has finer individual wire strands for flexability. Thicker strands will someday break due to constant bending back and forth. So will the thin ones, but it takes a whole lot longer.

 

[kodibass]

Re: 1976 25 hp Points question

If you have a outboard shop in your area that works on the older engines, take your driver-ext coils to him, he will have a mer-o-tronic type tester and can check them for you, most likely will not charge just to check them, it takes about 2 min. Buy new point & condensers about $ 12.00 for both sets. replace the spark plug wires also 70 cents a ft. replace your plugs with new ones and gap them at 30* use your old ones as spares. You now have a completely tested / new ignition sys from A to zpark. total cost less than $25.00 happy boating----priceless!

 

[69 Alumacraft]

Re: 1976 25 hp Points question

Good to know, still glad I did it even if I have to replace them again someday. Thanks, will update when I test her out.

 

[oldman570]

Re: 1976 25 hp Points question

Like F_R stated the wire you used will work, but not as long. If IBoats dosen't have replacement wires try going to Crowelly Marine or Sea Way Marine. They should have them there. The little plastic that they go thru near the points is also very important. If you have have more trouble with anything come back ,cause we try our best to give advise that is worth while.
Have Fun and BE Safe

Oldman570

 

[69 Alumacraft]

Re: 1976 25 hp Points question

More trouble. Running rough in the barrel. It seems to Idle high or not at all. To review, carb has been rebuilt and works well on my other motor (1969 25 hp Rude sportster), new fuel pump, new driver coil,new points and condensers, compression 130 on both, replaced wires from coils to points, good spark on both. I am having trouble w/ link and sync and adjusting the position of the cam roller but it seems to either idle too high or too low also messing with low speed carb adjustment. Still have a cracked ignition coil but it is throwing good spark on tester? Is this a timing issue? I have a new coil coming, thermostat and cam roller.

 

[HighTrim]

Re: 1976 25 hp Points question

I would not bother adjusting anything until the new coil is installed. Throws a good spark on the tester while not under load, but in the water you are talking about completely different scenarios.

After that, start with the low speed needle 1.5 turns out from lightly seated. Thread it in 1/8 of a turn or so at a time, waiting for the motor to respond. When it starts to backfire mildly, it is too lean and back it out 1/4 turn. Within that 1/4 turn is the ideal idle position.