1989 Evinrude VRO V4 90HP will not idle and cuts out after engine gets warm.

[fishburn64]

I have owned this engine for several years and it has always had a hard time staying running at idle requiring me to run it at fast idle and quickly hit the throttle to keep it running. However, recently it has been the same when cold starting but after running the engine for several minutes it begins to miss or cut out at full throttle and after tuning the engine off it starts but dies before I can get the high throttle down and into gear. I'm hoping someone can help me repair this motor as a new one is not in the cards at this time. Spark plugs look fine.

 

[ricohman]

When was the last time the carbs were rebuilt? If it won't run at idle, and only high speed, the low speed jets are probably plugged.

 

[jakedaawg]

Step one compression test. Report back

Stwp two open air gap spark test set to 7/16" report back.

Step three fuel sample into clear container report back.

Welcome to iboats. Glad you found it. Do these tests first and we can step you through it so you buy only what you need and save yourself a bunch of time.

Tools such as compression guages can be rented at parts stores. Spark tester you need to buy, they are cheap.

Search the forums for one and you will find a picnso you know what you are looking for.

 

[racerone]

These motors are just excellent when in good condition.---But they suffer from poor ring design.---Start with reporting the compression numbers.

 

[emdsapmgr]

You should do some ignition testing. When ignition components get old, they become more affected by heat. Old components may run the ignition just fine, till the engine warms up to normal operating temps. This "normal" heat is enough to cause an electrical component to fail in some mode or another. So, when the engine is warmed up, that's when it's best to test the ignition components: stator, timer base and power pack. You will find some excellent ignition trouble shooting info at this website: cdielectronics.com. You'll need a special "peak reading" voltmeter, as a normal household one won't do.

 

[fishburn64]

Thanks for the advice, I'll check the compression and get back to you. Since my original post I have checked the spark plugs and found one cyclinder that had enough water to fill the spark plugs area around the ceramic. It smells lightly of gas. Cleared the cyclinder and replaced the spark plug and the engine starter and ran fine. Went to the lake and started engine, the pee stream sprayed intermittently as if compressed air was in the line. Drove the boat a short distance and the engine lost all power and steam was coming out of the cover. Does this change anyone's advise?

 

[fishburn64]

One last thing the fuel has been tested and no water was found but just to certain I replaced the water separator.

 

[jakedaawg]

Water in cylinders is bad. Pull heads and pray for a bad head gasket. It probably in the exhaust though.