1981 evinrude 115 hp recirculating hose diagram

sure if a hose is broken will get bad idle but not rough running at 3500 under load and if a hose is busted you will find it in 2 seconds when running with the cowl off.

There is no vacuum operating the system the crankcase pumps it through the one way valves in to bypass covers hence finding a broken hose is very easy.

squeeze all the hoses shut and see it it goes away
also check the hoses from the primer solenoid.

Could also be a stuck open valve in one of the nipples in the inlet manifold
Could have a vacuum leak elsewhere but very rare in that design unless a carb is about to fall off
once you are inside the crankcase a vacuum leak is also a pressure leak
so only between carbs and reeds

 

Frosty right again ..dont you just love that man ....

 

I am --geez what did I say?

 

Vacuum and whats more you can spell it ....

 

hay frosty what you packing in that pipe there "spinach"? lol

 

LOL thats not me thats the wife.

 

anyway
what did you find with your engine?
Have you bought a tacho yet?

 

im a industreil repairman by trade i had a sperr v.o. for high voltage, it was a coil i guess it had a bad spot and would jump over it at higher voltage,i had to read the dva specs for about 4 days before it all came together,"you get a little bit older, you get a little bit slower" lol , i guess

 

i found a bad coil.I replaced it and it ni longer is missing but is hard to start and does not idle right