Evinrude 25hp, petrol mix and running tips please

[zhaan]

OK, so I have an Evinrude 25hp 1985 with a sticker on it reading 100/1.

I posted before about the petrol mix and got very good replies which made perfect sense.

I will tell the full story then give me your diagnosis Doctors!

I bought the 25hp Evinrude.

I mixed 100/1 petrol, it ran perfectly.

Took it to sea, opened it up after building up the speed over 45 minutes.

I pipe came off the primer circuit causing air to enter the engine, the engine stopped dead. Failed to start it.

Got it home, took the leg, checked the shaft, unmarked, everything unharmed.

Changed the sparks for new.

Checked the carb needle valve which I found to be 12 turns out.

Screwed valve in then brought back out 1 and a half turn out, as per advice and guides.

Put it back together, started running it on 50/1.

Since all that happened, the engine just will not run on idle.

I prime, I start (manual start), she runs for a short time, it seems it runs on the fuel that was sucked through on the primer then stops, bulb on fuel line still solid.

Could I honestly have an engine that really does need to run on 100/1?

Any help or thoughts on this, as you can tell, would be hugely appreciated!

She aint going to sea again until she idles!

 

[HighTrim]

Re: Evinrude 25hp, petrol mix and running tips please

Pull that sticker off and run her on 50:1

If you continually pump the primer bulb does it keep her running? What about spraying pre mixed fuel into the carb throat? There is a good thread in the FAQs by Joe Reeves about setting the needle.

I would start with the basics and check the spark and compression then go from there. A full carb clean and rebuild is probably in your future.

 

[Vic.S]

Re: Evinrude 25hp, petrol mix and running tips please

Could I honestly have an engine that really does need to run on 100/1?

no, but you could always try the 100:1 mix again.

if it runs on that but not 50:1 then I think every one will be stumped!

Have you tried screwing the needle valve out further to see if it will idle.

If it has to be unscrewed by more than a small amount to get it to run then you should be looking at cleaning the carb paying particular attention to the idle circuit.

Will it idle if you operate the primer. If so it points to the need for a carb clean

 

[Rudi2]

Re: Evinrude 25hp, petrol mix and running tips please

Have you tried screwing the needle valve out further to see if it will idle.

If it has to be unscrewed by more than a small amount to get it to run then you should be looking at cleaning the carb paying particular attention to the idle circuit.

Agreed, if it ran ok with the needle out that far, something is a little hinkey. But if it works...well??
Sounds like a carb rebuild would help.

 

[zhaan]

Re: Evinrude 25hp, petrol mix and running tips please

Thanks all for your responses, yes if I continue to pump the primer just before it cuts out, then she runs a little longer.

Also agreed, if it runs well when the needle valve is 12 turns out, then that aint a good sign!

By the way, if anyone has a manual for this engine I would pay for a copy! I contacted Evinrude and they said its too old for them to have a manual.

Thanks again folks.

 

[Vic.S]

Re: Evinrude 25hp, petrol mix and running tips please

The supplier of Evinrude manuals is Ken Cook at www.outboardbooks.com

They are not cheap!
You have not told us the model number of your engine, I dont think, but I checked for E25RCO and found the owners manual is about $35 US and the Service manual about $70 US.