need help

[gdido]

I have an 1975 evinrude 85 starflite out board. The engine runs great out of the water but once a put it in the egine does not want to run. I have replace the spark plugs, cleared the fuel line and replaced the fuel tank. The boat ran last year, for the guy I bought it off of, but she dosen't want to run for me. Any suggestions would be great TY.

 

[Boss Hawg]

Re: need help

Start with basics---
Compression
Spark
Fuel
Read the Top Secret files at top of page

 

[mikesea]

Re: need help

the answer is likely in the 'it ran last yr'it doesnt take long for a sitting eng to have its carbs varnish up.Cleaning the fuel line is just a small step.As said,spark ,compression check ,you will want to determine which cylinders arent firing.You can run it on a hose and pull the plug wire off one at a time,that can help you locate any dropped cylinders.But I would bet your carbs are dirty

 

[gdido]

Re: need help

When I pulled the plugs the top two are getting black quik and the bottom two look brand new. Why would this be? I will do a compression test and clean the carb. but would I also need to change my plug wires?

 

[mikesea]

Re: need help

the 2 plugs that arent firing are probably not getting fuel due to a dirty carb,you should check spark on all cylinders,your bottom carb is the culprit,it isnt allowing fuel to get to the cylinders,if you said it was just one side,top and bottom,that would lead me to believe it was spark problem,the common element here is carb,but you should get a spark tester and check anyway,the carb will need to be totally disassembled,should be soaked in a solution,and blown clean with compressed air.I suggest you clean both carbs,likely they sat and became varnished,flush all ful lines prior to assembly.Your plug wire should not be an issue unless you see obvious trouble

 

[gdido]

Re: need help

Thank you Mike I will do everything you said and post back on monday Have a good week end every body!