vro oil injection

baitmaster

Cadet
Joined
Jul 4, 2011
Messages
23
The other day I ran about 10 gal of gas thru my evin 150. Got home and while looking boat over, I noticed the oil tank seemed to be caving in slightly on one side. Opened the lid, and it came back out. Do these systems operate on a vacuum, or a pressure system to get oil to the motor? Noticed occasional blue smoke while running slow, but not excessive. I never sqeeze the oil primer bulb as it always seems pretty stiff. Warning horn on key operates normal.
 

d.boat

Chief Petty Officer
Joined
Sep 19, 2008
Messages
520
Re: vro oil injection

The other day I ran about 10 gal of gas thru my evin 150. Got home and while looking boat over, I noticed the oil tank seemed to be caving in slightly on one side. Opened the lid, and it came back out. Do these systems operate on a vacuum, or a pressure system to get oil to the motor? Noticed occasional blue smoke while running slow, but not excessive. I never sqeeze the oil primer bulb as it always seems pretty stiff. Warning horn on key operates normal.

Oil primer will always feel stiff.

The oil tank shouldn't have a vacuum, if that's what you were seeing. The cap is vented allowing air to get in to replace the oil that's flowing out. You should probably check the cap to make sure it's functioning properly. You might also want to mark the oil tank, run 5-10 gallons of gas through it, re-fill oil to the mark, and see if it's burning the proper amount of oil for gas burned - run pre-mix in the mean time just to be sure.
 

baitmaster

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Jul 4, 2011
Messages
23
Re: vro oil injection

I had started with a full oil tank. After about 10 gal thru it, it looks like the oil res is about a qt lower. Seems like it was getting enough oil, as I was trolling several times, and after opening it up, i would get some blue smoke as it was cleaning the exhaust up for a couple of seconds. I know its not real good to idle these motors for extended periods, but it didnt seem to mind as it would idle for as long as I wanted. I am going to check that cap, sure seemed like the tank wanted some air as I opened it. This tank assembly was brand new along with a completely rebuilt top end, starting with the block, pistons, crank, etc. Prob only has 20 hrs on it, but that cap is bugging me after your diagnosis.
 

baitmaster

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Jul 4, 2011
Messages
23
Re: vro oil injection

Today I unscrewed the oil tank cap. Tank had a little positive pressure in it. So now I dont know what to think. Had tank vacuum one day and pressure the next. Don't see how this cap could have a vent on it, just a solid cap from what I can see. Could the tank be vented somewhere else? Maybe i'll just run it with a loose cap.
 

boobie

Supreme Mariner
Joined
Nov 5, 2009
Messages
20,826
Re: vro oil injection

The tank should be vented. OMC had some probs with those caps so you should just get a new one. If it's out of the rain you could leave it loose.
 

baitmaster

Cadet
Joined
Jul 4, 2011
Messages
23
Re: vro oil injection

thanks for that info. I was thinking about maybe a 1/16" hole in the top of the cap, as it is under my back deck area. How would the bulb stay stiff with no pressure in the line, and the oil won't drain back down the hose from the motor?
 
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