Gas/Fuel System Questions

Ed Y · May-11-2008, 03:38 PM

Hey guys - I've been having some issues with smoke from my 93' Johnson Oceanrunner 225 (VRO). Its always smoked, but it seems to be significantly worse over the past few trips.

From what I've read - too much oil in the mix can be caused by a couple of things: 1) air leak in the fuel line (fuel pump is busy pumping fuel instead of gas resulting into too high a mix), 2) fuel line restriction (resulting in the same) or 3) bad fuel pump.

This past weekend, I replaced the both fuel filters (cannister and clear inline) along with a couple of the fuel hoses. After replacing the inline (mounted horizontally under the engine cowling) - I noticed that it is almost always half full of air - even if I pump it full of fuel, with a second of starting up the engine its 1/2 empty. Is this normal?

I also seem to dripping 2stroke oil out the bottom of the intake where it means the air silencer. The gasket is pretty much gone there... have one on order, but it doesn't seem like there should be that much oil in that part of the engine. Any ideas on if that is normal and/or what might be causing it?

Thanks,

Ed

sickcat · May-12-2008, 05:02 PM

Not an expert on VROs by any maeans but IIRC they are somewhat known for oil pump issues. I know some guys dump the oiling system and just run it on premix. I am not suggesting that - just saying. If you ran it for 2 trips and had excessive smoke but otherwise ran OK then I would suspect the oiling system. If your running lean on fuel that is a bad thing and I would suggest fixing the issue before running it again. That is a good way to burn a piston/score a cylinder.

JUST-IN-TIME · May-13-2008, 10:17 PM

sounds like i would run pre-mix

i need to check the vro out

Duramax · May-14-2008, 05:17 AM

sounds like one of your oil level sensors is stuck , your top tank on the engine thinks it's low so it keeps telling the lower tank pump to resupply ans pump up more oil.

Thus causing the upper tank to overflow, the overflow drains into the air box.
Then it runns out of the air box.
If the air box gets splashed with the extra oil and the engine is running, it will suck the additional into the engine plus what is normaly injected.
Thus causing the extra smoke.

Take out the oil tank sensors and clean them with carb. or brake cleaner.
I had that issue with my old yamaha engine, I also had a computer that would tell the oil injection to keep pumping the oil. Caused the same problem.

Good luck.

Ed Y · May-15-2008, 05:52 AM

Thanks for the info guys... Problem sounds very similar to the one Duramax mentions, but I don't think the VRO system on the Johnson is nearly that complex as the Yammy. On the Johnson, the oil and fuel both come into the same pump which does the mixing - so not really any sensor to speak of... at least that I know about.

I this point, I'm leaning towards air leak on the fuel side or bad pump...

Thanks,

Ed