1969 85hp starflite, low power and cutting in and out

[68glasspar]

This is the amplifier thats on it now. It's not 55yrs old, but is this vintage of amplifier also troublesome? Can it give just a reduced power symptom?

 

[jimmbo]

Well, as mentioned, Heat can reck Havok on Electronics, regardless of Vintage. It looks like it is mounted on a Heatsink... Is there supposed to be a Thermal Paste between the 2?
If you have ruled out all the other Components as being the Problem, and all Connections are Electrically Secure, then there could be a Problem with the Unit.
I have never heard of Wabash, so have no idea of their Quality/Robustness...

 

[racerone]

That was the factory replacement amplifier like 40 years ago.----Does spark jump a gap of up to 1/2" on a test device , yes or no.----Check each lead.----Perhaps run at night and see if spark is leaking under the flywheel.----Have you cleaned all components under the distributor cap.----Anti reversing spring in place ?-----Checked fuel pump?----Test run with another tank and hose ?

 

[68glasspar]

That was the factory replacement amplifier like 40 years ago.----Does spark jump a gap of up to 1/2" on a test device , yes or no.----Check each lead.----Perhaps run at night and see if spark is leaking under the flywheel.----Have you cleaned all components under the distributor cap.----Anti reversing spring in place ?-----Checked fuel pump?----Test run with another tank and hose ?

It has only one coil to fire, the dist cap and wires are NOS, was the same with older cap and wires, yes new anti reverse spring, new fuel pump installed, tried a different fuel tank and hose off my Johnson power fishing boat,

Next i will check charging system, maybe im getting under 12 volts while running

 

[68glasspar]

Will the motor run at reduced power(rpm) if the amplifier is running with less then 12 volts?

 

[racerone]

Yes ---I know it only has 1 coil.----Good luck with this motor.

 

[68glasspar]

Yes ---I know it only has 1 coil.----Good luck with this motor.

If thats the way you feel! But most of the time when i ask a question, instead offering an answer, you ask me to try things that were already tried before!

 

[racerone]

Good luck with your motor.

 

[Nordin]

Try to heat up the amplifier with a heating gun and check if it fails.
Do not heat it up to much with the heating gun!!
135-140 dgr F (55-60 dgr C) is enough.

 

[jimmbo]

If thats the way you feel! But most of the time when i ask a question, instead offering an answer, you ask me to try things that were already tried before!

This thread is already 50 posts long, so all you have to say to racer's request is that it was done, and the Results. He is one of the best on this Board when it comes to Motors of that Era.

 

[68glasspar]

This thread is already 50 posts long, so all you have to say to racer's request is that it was done, and the Results. He is one of the best on this Board when it comes to Motors of that Era.

please read posts #43-44- 45-46

 

[68glasspar]

I purchased an adjustable spark tester and checked all 4 plug wires for spark, the spark was barely able to a 1/8" gap!

 

[Nordin]

That seams the culprit with your issue.
Looks like the capacitors in the amplifier are bad.
They dry out when old and you get lower output voltage from the amplifier to the coil.
Have you check the coil?
Bad insulation and it will fail when gets warm.

 

[68glasspar]

That seams the culprit with your issue.
Looks like the capacitors in the amplifier are bad.
They dry out when old and you get lower output voltage from the amplifier to the coil.
Have you check the coil?
Bad insulation and it will fail when gets warm.

thanks for the response! I removed the coil wire from the dist cap and checked for spark at it. The spark was able to jump at least 1/2" there. So before i order anything, i guess i need to look dist cap and rotor over good for any signs of leakage of spark potential.

 

[jimmbo]

I believe you said you replaced the Rotor and Cap.

 

[68glasspar]

I believe you said you replaced the Rotor and Cap.

Nope, i said i replace the dist. cap and wires with a NOS part. This what i found today. Looks like there was a spark leak to the wavy washer. The resistance between the outer rotor terminal and the inside contact is high mega ohm range. The nos cap and wires i installed check good.
Im thinking i should try a rotor, before i condemn the amplifier and coil.
Any other thoughts??

 

[68glasspar]

I cleaned the inside brass ring of the rotor, so now the resistance is good on the rotor, but i would imagine there is still some place that leaks to that wavy washer that i can't find with my fluke.