old johnson 25hp wont crank

[heath parrish]

need a little help I have an old 25hp outboard always been hard to crank for the last year i had to spray starting fluid in the carb. in order to get it to crank the last time i had it out i got it to crank went about 2 miles up river and it acted like it flooded out and cut off let sit for 3 hours while i hunted and never got it to crank again with are without starting fluid. put new plugs in and still no go.

any help please

 

[Silvertip]

Re: old johnson 25hp wont crank

Keep using starting fluid and it may never crank again. Just to clarify, CRANK means to turn over. An engine may turn over but not start. When it starts it is running, not cranking. I assume you mean the engine cranks on the starter but does not ru -- correct? If so, check for spark on each cylinder. An engine needs fuel, spark, and air and everything needs to happen at the correct time or it won't run. An engine that is worn out or has no or low compression will also have trouble starting and running. Use of fresh fuel is also necessary.

 

[Lion hunter]

Re: old johnson 25hp wont crank

!st never, ever,ever,ever use starting fluid on a 2 stroke. No lubrication and it will score your cylinders. If needed use premix in a spray bottle. 2nd starting fluid will not help any motor crank. The battery cranks it, fuel fires it. So if the battery is fully charged and it's cranking good I would take a look at the carbs. When's the last time rebuilt. Also check the low idle screw. Start at 1.5 turns from seated and turn in till it starts to stumble, back out 1/4 turn from there. Is it getting good spark? How does it run once it's started.


Sorry for the repeat Silvertip beat me to it.

 

[tashasdaddy]

Re: old johnson 25hp wont crank

lots of help here, check compression, spark, carbs, ethanol, impeller.

 

[heath parrish]

Re: old johnson 25hp wont crank

!st never, ever,ever,ever use starting fluid on a 2 stroke. No lubrication and it will score your cylinders. If needed use premix in a spray bottle. 2nd starting fluid will not help any motor crank. The battery cranks it, fuel fires it. So if the battery is fully charged and it's cranking good I would take a look at the carbs. When's the last time rebuilt. Also check the low idle screw. Start at 1.5 turns from seated and turn in till it starts to stumble, back out 1/4 turn from there. Is it getting good spark? How does it run once it's started.


Sorry for the repeat Silvertip beat me to it.

thanks i have already changed the fuel out with new i should have said that it is a pull cord start not electric it is getting good spark when i try to start it the last time i had it out it ran great

 

[samo_ott]

Re: old johnson 25hp wont crank

What year / model is it?

And you can use Deep Creep as a starting fluid as it has lubricant built into it. I was using it today on my lawnmower (which is 4 stroke do it doesn't really matter though)

 

[Lion hunter]

Re: old johnson 25hp wont crank

With that info I would start with a carb rebuild and replace all fuel lines. Then go from there. It's the quickest, cheapest thing to do that is the cause of alot of problems. Fuel line and kit will run about $30.