Evinrude 90HP won’t go over 2000RPM

[Cameron119]

Evening everyone. Short back story. Had my 90 evinrude (E90eleuc) serviced last year was purring like a kitten. We were out tubing and all of a sudden after going in neutral to switch riders we can only go 2000rpm. I noticed one of the sides of the engine feels very hot to the touch, the other side is good.

Things I’ve checked
-throttle response seems fine, at full throttle the RPM is limited.
-spark is good on all 4 cylinders.
-Disconnected the thermostat wires and ran engine, same problem.
-removed the thermostat on the hot side put in bowl with boiling water and it opened. Cool water closed it.

I’ve read something about a neutral switch is that inside the actual OEM throttle beside the seat?

Any suggestions would be great

 

[jimmbo]

All the Cylinders getting fuel? If not, they aren't getting Oil. What do the Plugs look like?
As for Good Spark, is it good enough to jump a 3/8" gap?
Have you tested the Compression?

 

[Cameron119]

When I pulled the plugs they were only slightly discoloured and had a very light brown coating, not hard carbon. We tested all 4 plugs one at a time and looked for spark and it looked good, the plug gap seemed quite wide, I’d say around 3/8.

As far as compression I won’t be able to check until I get back home on Monday.

 

[Berdink]

When I pulled the plugs ...clip... the plug gap seemed quite wide, I’d say around 3/8.

Are you saying the plugs had a gap of around 3/8?
Or that you used an adjustable spark tester and the spark jumped the 3/8 gap on the spark tester?

 

[Cameron119]

Roughly 3/8” gap. I did not use a spark tester we pulled the plug and re attached the wire with it grounded on the power head to test spark.

 

[saltchuckmatt]

You said one side was hot...old school method, warmed up and fast idling...touch the top of the head where it meets the block, it should not be scalding. Port a few degrees cooler but not noticable to the human hand. Port side head have a two wire sensor? Tan wire and a white wire? Could be "slow mode"

 

[jimmbo]

Roughly 3/8” gap. I did not use a spark tester we pulled the plug and re attached the wire with it grounded on the power head to test spark.

What was approx 3/8" gap? A regular spark plug has a gap of 0.030", 3/8" is 0.375", almost 13 times wider