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1975 70hp model 70573E.....more problems.

R

Retired OG

Contributing Member
Well, the new starter (9 tooth ARCO) works wonderfully....now I'm being plagued with another problem...once it fires up, it only wants to run on one, sometimes two cylinders and it seems to not matter which one.....(or two) seeing as how I pulled the plug wires one at a time....the last time out, it ran on all three (in gear) for about a minute after putting around for a half hour or so on one....sometimes two....one other thing I noticed was when it seemed to be running on one, is that if I manually throttle while in neutral, it will surge up to 4K rpm....I'm fairly certain this isn't a fuel problem and is either an ignition module or stator issue...I've read the repair manual and the troubleshooting manual from CDI electronics, but I live out in the sticks and need to get somebody to turn the key...any guesses?
 
With the spark plugs removed... you can crank the engine over to test the spark or the compression, whatever simply by using either a mechanics push button tool... OR... a small jumper wire... one end of the jumper wire connected to the large terminal of the starter solenoid that the battery cable is attached to... and then with the other end of the jumper wire, temporarily touch the 3/8" nut terminal on the starter solenoid to engage the solenoid... NOT the 3/8" nut terminal that leads to ground.

You need to have good compression and spark that will jump a 7/16" gap with a strong blue lightning like flame... a real SNAP! Note that the 7/16" gap is important! Let us know what you find.
 
Might be getting water into the cylinders from warped exhaust cover.
 

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fdrgator said:
Might be getting water into the cylinders from warped exhaust cover.
Click to expand...

That happened on my old 50hp....no evidence here for a warped exhaust.....Joe is on track here...I'm gonna have to make a spark gap tester this morning.

I'm pretty sure my stator is gone...
 
Retired OG said:
That happened on my old 50hp....no evidence here for a warped exhaust.....Joe is on track here...I'm gonna have to make a spark gap tester this morning.

I'm pretty sure my stator is gone...
Click to expand...

If so... Yeah, that'd do it. Check visually to see if a sticky looking substance is dripping down on the powerhead from the stator. if this problem exists, that would result in a AC voltage drop to the power-pack's capacitor which in turn would result in weak, erratic, and eventually no ignition (spark).

Oh, something to build............

********************
(Spark Tester - Home Made)
(J. Reeves)

You can use a medium size philips screwdriver (#2 I believe) inserted into the spark plug boot spring connector, then hold the screwdriver shank approximately 7/16" away from the block to check the spark or build the following:

A spark tester can be made with a piece of 1x4 or 1x6, drive a few finishing nails through it, then bend the pointed ends at a right angle. You can then adjust the gap by simply twisting the nail(s). Solder a spark plug wire to one which you can connect to the spark plug boots, and a ground wire of some kind to the other to connect to the powerhead somewhere. Use small alligator clips on the other end of the wires to connect to ground and to the spark plug connector that exists inside of the rubber plug boot.

Using the above, one could easily build a spark tester whereas they could connect 2, 4, 6, or 8 cylinders all at one time. The ground nail being straight up, the others being bent, aimed at the ground nail. A typical 4 cylinder tester follows:

..........X1..........X2

.................X..(grd)

..........X3..........X4

This can obviously be modified to a 6 or 8 cylinder setup tester.

********************
 
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Mr. Reeves, you just described MY spark tester. I also can adjust the gap with the alligator clip on the ground wire which I simply attach to my "ground nail" where it can arc the desired testing distance over to the "hot nail". A good mechanic is also a decent carpenter.
If I was going to really love my 70 hp, I would replace all the ignition components, except maybe the coils.....they are pretty definite......with new CDI parts....
Get 'em on line, Mr. OG. You really don't need any troubles out on the water. Besides that, do you have any idea what it would cost to replace that with a new 70 hp? Without considering the added weight besides? A new Yamaha is over 8 grand and an E Tech by Evinrude is over 6 grand. Ouch!
You then know the definition of a boat.........."a hole in the water you throw money into." The "good" thing about a new motor is that you don't have to buy expensive non-oxy fuel......and you can feel better about the environment.
Ps. Your spending your families inheritance, but they might get a nice boat out of the deal.
 
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joereeves said:
You need to have good compression and spark that will jump a 7/16" gap with a strong blue lightning like flame... a real SNAP! Note that the 7/16" gap is important! Let us know what you find.
Click to expand...

OK....I built a spark tester & got #2 & 3 cyl. firing across the 7/16...no "snap" or blue lightning like spark, more of a thin white streak...I swapped coils #1 & 2 with the same results, so the coils are good. I also did all the ohms tests listed and they all came back in spec. The only reading that had me concerned was the voltage (160) from the stator......Soooo is it just my power pack? Should I be concerned with the low voltage?
 
If that stator is dripping a sticky looking substance down on the timer base and powerhead area, that would result in a AC voltage drop to the powerpack capacitor... in turn resulting in weak, erratic, and eventually no ignition (spark). If this condition exists, replace the stator regardless of whatever reading you get from it.
 
joereeves said:
If that stator is dripping a sticky looking substance down on the timer base and powerhead area, that would result in a AC voltage drop to the powerpack capacitor... in turn resulting in weak, erratic, and eventually no ignition (spark). If this condition exists, replace the stator regardless of whatever reading you get from it.
Click to expand...

No dripping...
 
joereeves said:
If that stator is dripping a sticky looking substance down on the timer base and powerhead area, that would result in a AC voltage drop to the powerpack capacitor... in turn resulting in weak, erratic, and eventually no ignition (spark). If this condition exists, replace the stator regardless of whatever reading you get from it.
Click to expand...

Joe....I'm a really poor old guy...I'm trying to sell some stuff right now so I can buy a new power pack.........If I get one and the motor starts running good, what are the chances of me damaging it with a low voltage stator??? A new stator will take me a while...
 
The spark test is to be done with all the spark plugs removed. Were they?

The voltage from the stator depends on the cranking speed of the engine. A slow cranking engine will not produce much of a spark. Is your engine cranking over fast, at least 300 rpm?
 
joereeves said:
The spark test is to be done with all the spark plugs removed. Were they?

The voltage from the stator depends on the cranking speed of the engine. A slow cranking engine will not produce much of a spark. Is your engine cranking over fast, at least 300 rpm?
Click to expand...

I don't know because I was jumping the motor at the solenoid switch, but yes the plugs were removed. It was cranking pretty good with that new starter in...
 
Power packs can fail just from storage. Stators and triggers are more predictable. I just changed a power pack and now the motor is fine, the guy is on a budget too. Put on a used one. It was running last summer 2017, then dead when he went to try it in August 2018. Power packs are VERY unpredictable. Used power packs at Tim's Outboard, Hackensack MN. Tell 'em Tim sent you. 218 682 2331, they are celebrating their 50th anniversary. Closed Sat. and Sun. They have beautiful used parts from northern MN, no salt and its a family run business. Tim is still alive. Mike or Dan will help you.
 
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timguy said:
Power packs can fail just from storage. Stators and triggers are more predictable.
Click to expand...

Thanks Tim....If I do get a power pack, is there any chance that the stator or timer base could damage a new power pack?

ETA: I may be able to get one sometime this month if I can sell something....
 
It depends on how the problem started. I have most often seen power packs get bad when the motor has been out of use, not while they are in operation. There are some effective ways to test the other components but that might be outside your comfort zone.
 
timguy said:
It depends on how the problem started. I have most often seen power packs get bad when the motor has been out of use, not while they are in operation. There are some effective ways to test the other components but that might be outside your comfort zone.
Click to expand...

Well, the motor hadn't been used for 15 years, until I resurrected it...it ran great the first two "test" trips to the lake....then it sat for another two months this summer while I took care of my brothers cataract surgery.....
 
I just quick-read thru all the posts/replies and see no mention of this test I'm mentioning right now.........

I'm assuming you're still having a "No Spark" problem.

Remove the Black/Yellow wire (kill circuit) from the ignition switch "M" Terminal. Test for spark.

If you have spark with that black/yellow wire disconnected but no spark with it connected... that indicates a short within the ignition switch, in which case, replace the switch.
 
joereeves said:
I just quick-read thru all the posts/replies and see no mention of this test I'm mentioning right now.........

I'm assuming you're still having a "No Spark" problem.

Remove the Black/Yellow wire (kill circuit) from the ignition switch "M" Terminal. Test for spark.

If you have spark with that black/yellow wire disconnected but no spark with it connected... that indicates a short within the ignition switch, in which case, replace the switch.
Click to expand...

Thanks for the try Joe, but it's not in my ignition switch ...#1 cyl. was dead at the power pack....I did finally get the flywheel off and found a half sheared key, some mud daubber homes in the timer base and noticed I have a few thousandths play in the base....that still shouldn't cause the #1 terminal to crap out...right now, I can barely afford the power pack and am gonna roll the dice on just the power pack....the timer base will be on the priority list though and I'll pick one up when I can scavenge up the cash....
 
Can you play the guitar, or sing? Works for me downtown on the corner...... My sign reads, old mechanic, no work, can't operate computer. Need food. Everybody loves Johnny Cash.
Get all your parts from Tim's. They may discount for retired guy.....they do me.
 
I woke up Sunday Morning... No way to hold my head that didn't hurt!.... :rolleyes:

My sign read "Homeless, Lazy, Pregnant"... They gave me nothing!
 
joereeves said:
I woke up Sunday Morning... No way to hold my head that didn't hurt!.... :rolleyes:

My sign read "Homeless, Lazy, Pregnant"... They gave me nothing!
Click to expand...

Yeah...well.....you were trolling with the wrong bait....I couldn't carry a tune in an empty semi-trailer...nor play a guitar....I do like Old Johnny Cash tunes, but prefer music like this....

 
Good job, brother. Thanks for the report. Allan Jackson (country music) has a song that mentions a '75 Johnson with electric choke.....old wood boat. Brings me back to my younger days.....check it out.
 
Retired OG said:
Update....The new power pack took care of the problem...
Click to expand...

I bought a boat and the motor was not running. Seller had a new CDI part. Put that in and it would run. Then I read all the stuff about low voltage potentially ruining the power pack or the replacement CDI part. I abandoned that and put in the MSD 6A with a dual coil unit used on V OMCs wired in series with one grounded. What a difference that makes and I don't have to worry about low voltage or deep cycle or AGM batteries. Just sayin.

https://www.ebay.com/itm/223154341517
 
TTFullTimer said:
I bought a boat and the motor was not running. Seller had a new CDI part. Put that in and it would run. Then I read all the stuff about low voltage potentially ruining the power pack or the replacement CDI part.
Click to expand...

Yeah, I've read that too....When I took it out the other day, it had 12.1 volts on the battery....I ran it for about two hours with the radio and fishfinder on and when I pulled up at the dock I had 12.5 It's kind of a moot point right now, because I couldn't afford any new parts anyway...
 
If your not on a tight budget its good to replace all ignition components together at the same time, but many of my customers are not able to afford that. My personal motors get the "royal treatment", seems I'm out in the middle of remote Ontario with somebody that doesn't like to camp out on the shoreline somewhere.
 
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