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Starting issue 1983 90hp V4

S

sjones73

Member
So, need a little help.
Motor runs great. But I have found out that after running for a little bit (20 plus minutes) and sitting for a bit. The motor is hard to start.
Primed the engine etc. pushing key in and still hard to start.

I have found out that if I trim up the motor it starts great every time. Seems kind of weird to me that trimming it up (prop nearly out of the water) It starts great.

Floats or carb issues?

Let me know what you guys think

Thank you
 
Some will argue.------Post the actual compression values of this motor.-----There could be issues with motor having to overcome backpressure.-----Also load test the battery.----Take starter apart for inspection and ohm test on armature.
 
Yep, usually worn out & back pressure causing issues. But maybe relief ports are plugged by a rodent friend?
 
Ok just did compression test. Digital gauge
Top left - 112.9
bottom left - 112.6
Top right - 113.3
Bottom right - 115.1

Did the compression test 2 times. Numbers where within .3 of the original readings I stated above.

Those seem to be pretty good reading for an older motor. Or am I mistaken?

Gonna get battery out in the next couple of days. And check the starter motor.
Relief valve?
 
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Relief ports, not valves. The slots or holes just under the cowling across the back.
They allow back pressure to escape.

Remember, a 2 stroke doesn't have an exhaust stroke so at cranking speeds it will suffocate if the back pressure of underwater exhaust isn't relieved.
Perhaps rodents have nested up high in the mid section?
 
Droid, Checked that all out. No rodents or anything in there.

Racer, Checked out the starter, it is all good. (per the Johnson manual)
Load tested the battery. It is on the low end of 9.2 volts when loaded at 78 degrees. So, battery is going to be replaced.

I think I need to let you know that the motor cranks good when it doesn't start.

I did notice that the spark plugs are pretty wet compared to what I have seen on my old 2 stroke dirt bikes. Plus, they do not look the best in my opinion. So going to get some new spark plugs while I am at it.
 
A good thorough Link and Synch may help . If anyone's messed with the linkages/carbs . Odd that it starts when tilted . My v4's were kinda temperamental . One thing for sure do not over advance the timing .
 
sjones73 said:
Load tested the battery. It is on the low end of 9.2 volts when loaded at 78 degrees. So, battery is going to be replaced.

I think I need to let you know that the motor cranks good when it doesn't start.

I did notice that the spark plugs are pretty wet ....Plus, they do not look the best in my opinion. So going to get some new spark plugs while I am at it.
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9.2V is pretty bad when cranking, so yes that battery needs replaced. Your engine needs to spin at 350RPM when cranking to generate the correct spark for starting. If you battery is that low, I could see how the back pressure would slow the cranking speed.

Since you said the spark plugs look wet I suggest using an air gap spark tester on each cylinder to make sure each lead can jump a 3/8" gap when cranking. If not you may also have ignition or grounding issues.

The correct spark plug for your engine is Champion QL82C gapped at 0.030". See the chart here: Evinrude Champion Spark Plug Guide I've always had great life out of Champion plugs in my Evinrude engines so I stick with them.
 
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