VRO constipated?

emsai

Cadet
Joined
Apr 23, 2008
Messages
8
1995 Evinrude 115 hp sleoc. Oil primer bulb hard as a rock. Never softens - at all. Is it supposed to be that way? Is there a sticking check valve? Gas primer bulb seems to be ok; soft, and pumps up firm. Sometime engine starts in a cloud of smoke. Other times it starts and runs rough. Once the RPMs are up, it goes like a bat out of Pittsburgh (of old.) Gas is fresh. Oil tank and gas tank always kept full. Suggestions?
 

ezeke

Supreme Mariner
Joined
Sep 19, 2003
Messages
12,532
Re: VRO constipated?

Rubber is a hydrocarbon and is either softened or plasticized by liquid hydrocarbons like oil and gas. Either way bulbs have reached the end of their economic life when they are hard and brittle or spongy and degraded.

Alcohol in the fuel accelerates the destruction of rubber, especially older fuel lines which were not alcohol resistant. Alcohol is a part of many fuel additives.
 

emsai

Cadet
Joined
Apr 23, 2008
Messages
8
Re: VRO constipated?

The bulb is hard from being under pressure, not from being old or chemically set.
 

R.Johnson

Rear Admiral
Joined
Sep 24, 2003
Messages
4,446
Re: VRO constipated?

The bulb is smaller than the bulb used for fuel, and even new they feel more firm. Same as the fuel line, there is suction, not pressure. If every thing is in proper order, either bulb is just a wide spot in the line when the engine is running. A manual spell's out how to do a consumption test on the oil pump.
 

EN2

Chief Petty Officer
Joined
Nov 19, 2007
Messages
404
Re: VRO constipated?

The only reason for the bulb in the oil line.is to purge air out of the oil line ,if you disconect it,and hook it back up.Never sqeeze this bulb when connected to the engine.
 

kenmyfam

Supreme Mariner
Joined
Aug 10, 2006
Messages
14,392
Re: VRO constipated?

1995 Evinrude 115 hp sleoc. Oil primer bulb hard as a rock. Never softens - at all. Is it supposed to be that way? Is there a sticking check valve? Gas primer bulb seems to be ok; soft, and pumps up firm. Sometime engine starts in a cloud of smoke. Other times it starts and runs rough. Once the RPMs are up, it goes like a bat out of Pittsburgh (of old.) Gas is fresh. Oil tank and gas tank always kept full. Suggestions?
Just took the VRO off my 140hp a few weeks ago. Removed the now unused tank and lines. Purged the line of oil and the bulb still feels hard as a rock with nothing in it. I think it is the nature of the beast.
Now on premix.
 
Top