1983 90hps Evinrude outboard. Runs fine til engine heats ups

[KDizzle]

Not sure what to do next! I changed fuel lines, power-packs, gas tank line, new battery. Fuel pump and filter seem fine. Starts no problem. idles fine. Runs great for about 10 mins. Then boggs down, loses power, roars back to life, dies. Hard to re-start, choke needed. Suspect coils but haven't check yet. Uses a lot of gas too. Not an expert by any means. Need help.

 

[emdsapmgr]

Re: 1983 90hps Evinrude outboard. Runs fine til engine heats ups

Possible that the engine has a weak ignition component. May run fine when cold, then, may loose spark on one or more cyls- once the engine heats up to normal operating temps. When the engine starts to act up, check for spark on each cyl with a spark checker or an inductive timing light. Let us know what you find.

 

[89foxbody]

Re: 1983 90hps Evinrude outboard. Runs fine til engine heats ups

I have this same problem with a '72 Starflite 100. Have you checked if your cooling system is working properly? I ended up taking my boat to a mechanic as I did not want to end up with a can of worms. I will let you know what he tells me when he diagnoses it.

 

[pckeen]

Re: 1983 90hps Evinrude outboard. Runs fine til engine heats ups

Hi,

I had a similar set of problems with my motor, a '69 Johnson. Tried cleaning, the carbs, but it didn't work. I've attached a link to the thread, with the advice I received. I eventually sold the motor (with full disclosure to the buyer). He was mechanically minded, and advised me he changed out the coils, and got the engine working properly. Here is the link.

good luck,

Peter

 

[KDizzle]

Re: 1983 90hps Evinrude outboard. Runs fine til engine heats ups

Just an update. Having a mechanic come over to clean/rebuild the carbs with kits from manufacturer tomorrow or Wednesday. Checked the spark plugs with in line spark tester and it appears to have a consistent flash on all cylinders. Seems weak but probably should have done this closer to night time than the middle of the day. Will post my findings soon I hope. Thanks for everyones suggestions. Also, doesnt seem to matter if the boat has time to warm or not. Starts up with one turn of the key, idles fine, takes off great, power down after 1000 feet but doesn't turn off when WOT. Will continue to run at half or less. Still blowning throught the gas.

 

[KDizzle]

Re: 1983 90hps Evinrude outboard. Runs fine til engine heats ups

Problem solved. Took apart the carbs and cleaned em up. Both of them had little pieces of rubber gas line under the float valve assembly. Replaced gaskets and boat ran better than ever.

 

[emdsapmgr]

Re: 1983 90hps Evinrude outboard. Runs fine til engine heats ups

The fuel lines on that engine may not be rated to handle today's ethanol fuels. Those that are not, tend to break down and cause problems like you encountered. You may want to consider replacing them all so it does not happen again.