1974 Evinrude 70 hp Help

[Bosunsmate]

Swap the good coil on to the other ones just to check its not something upstream of the coils.
Clean the spakplugs too
Im assuming you have put in new spark plugs
Gees i didnt know it was fathers day, thats what happens when you dont watch tv so much

 

[Decker83]

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Just testing to post a pic.

 

[Decker83]

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[Decker83]

another test..

 

[Decker83]

I took the boat to the lake thinking it would run ok. It did great for a few minutes. Got up on plane and hit 5200 rpm real fast. Then it started to shut down like it had no gas. Checked the primer bulb and it was hard. Pumped it a few times and no change in motor.
I have replaced the stator, timer base trigger, coils, spark plugs and water pump and the rectifier.
I have rebuilt the carbs. These carbs have no adjustment screws.
I did the compression test and readings were 140,150 and 130. Did a decarb with seafoam and new compression test with readings of 148,152 and 142.
Have not changed the power pack III.
Did the spark test with a gap of 1/2" . Top coil and bottom coil had the orange and white spark. The middle coil has a strong blue spark.

Can the power pack be breaking down on wot?

The motor was running great on the muffs and would rev up easy. Didn't rev more than 3500 rpm at short burst.
After the decarb it doesn't want to rev up to 2800 rpm and will not idle at 1000 rpm. motor dies.

Have a dva adapter coming in the mail. Will try to check the stator and timer base for voltage.

My main question is carbs or ignition?
Any help will be greatly appreciated.

 

[oldboat1]

no water sloshing around in the bottom of the tank.... or down in the hull of the boat?

 

[Decker83]

No water in the tank. All new fuel and oil. Had a little water in the hull first time out. Second time out did not get the boat off the trailer. Now I am just running on the muffs and water hose.

 

[Decker83]

My DVA adaptor came in and I did some test on the ignition system.
1. Checked brown wire and brown yellow for voltage. It read 279 volts Should read 150 to 400 volts
2. Checked brown wire and brown yellow for ohms. It read 670 ohms. Should read 400-600 ohms
3.Black/white wire to all 3 White/black wire for volts. Should read .6 volts
Sensor 1 = .67
Sensor 2 = .85
Sensor 3 = 1.1
4. Black/white to White/black for ohms. Should read 10-20 ohms
Sensor 1 = 8 ohms
Sensor 2 = 8 ohms
Sensor 3 = 8 ohms
5. Black/white to ground for volts. It read 318 volts. Should read 150-400 volts.
6. White/black to ground for volts. Should read 150-400 volts.
Sensor 1 = 308 volts
Sensor 2 = 309 volts
Sensor 3 =307 volts
7. Black/white and White/black to ground reads open. Should read open.
8. Disconnected timer base from power pack. All readings should be 100-200 ohms.
Connect red meter led to Black/white terminal and black meter led to Sensors.
Sensor 1 = 95 ohms
Sensor 2 = 96 ohms
Sensor 3 = 96 ohms.
9. Connect DVA adaptor to orange coil led on all 3 coils. One at a time.
Coil 1 volts = 314
Coil 2 volts = 318
Coil 3 volts = 312

To my understanding all the test or within specs.

Would any of you agree with me?

Next thing I think is wrong with the wot problem is the carbs.

Would any of you agree with me?

I can not run the voltage drop test with the boat in the water. It will not go over 3000 rpm now.

Any help will be greatly appreciated.

 

[Decker83]

Anyone have any suggestion?

 

[Decker83]

Since I did not receive any response ^^^ I pulled all the carbs last night and ordered new kits and jets for them. Had some trash in the middle carb. Hope this is the problem with the wot problem.
Will check the reed valves for any restrictions tonight.
Have a great day!

 

[Decker83]

First I would like to thank all of you for helping out on this endeavor.
After rebuilding the carbs it worked great. Took my daughter, son in law and their 3 kids and myself out today.
This boat is a 16 footer glass boat. On the GPS we got up to 30 mph.
Ran the boat for a solid hour an half with no problems.
Thanks again guys.

 

[oldboat1]

Coils in your pic seems to show some cracking (post #94) -- might be picking up some replacements for future use.

Good to hear it's up and running well.

 

[Decker83]

Thanks oldboat1. I have replaced all of the coils. That was some old pics to see if I could replace the photo bucket pics. Have a great day!

 

[GSX455]

Hello folks, similar problem. i have a 1974 70-HP and it will not start. I've jumped lead to the starter and it engages the flywheel, using a multi-meter and then putting power to the white and black leads of the solenoid engages.
I've disconnected the black/yellow kill switch for testing purposes only. even then it will not crack. I've fiddled with the neutral switch in the control box, no luck.
Could the power pack be bad?
Thank you for any help.