Oil Foued Plugs on a 92 Johnson 120

[Drewski Canuck]

I have a rebuilt 120 that just got a new VRO installed. This is a new to me motor, so I am not familiar with it, other than it runs strong and has high compression. It was oiling plugs causing hard starting, new VRO was part of the deal and the new VRO is way worse. A day of running and the plugs are fouled. Change plugs and she runs. Old plugs have to be burned clean to make them fire again.

Is the VRO at all adjustable? What is causing the over oiling?

Drewski

 

[profisher]

Disable the VRO and pre-mix the oil in the gas...serious...the VRO is not reliable. SG had a VRO engine in for service last week. They were surprised it was still running on the original unit. They disconnected it and were going to tell the owner to pre-mix from now on. 50 to 1 mix

 

[combover]

vro should be 100:1 at idle and 50:1 at wot.

are you trolling with the motor? are u sure it not a fuel issue like flooding?this would cause hard starting and fouled plugs it can even ruin them.
when is the last time the carbs were off and cleaned?
seems unlikely that the brand new vro is doing the exact same as the old one.
have you burned through the gas that came with the boat maybe the previous owner had mixed it ( if the vro was bad) so it would be getting double oil now. i ask that because it sounds like you haven't owned the boat very long.
is there excessive smoke @ start up and idle?

you could disable the vro as mentioned but if your trolling around at 50:1 you'll end up with a similar problem.
the unit is not adjustable.
one problem i've seen over the years with the vro is good owners go to store the boat they run it out of fuel but the oil is still pumped into the carb filling the float bowls with oil.

 

[Saxe Point]

Before you disconnect your VRO system, you may want to read this: http://continuouswave.com/whaler/reference/VRO.html

 

[Drewski Canuck]

the Shop put Amsoil in the fuel tank as a preventative measure in case the VRO did not function. As such, a double dose. Nedt thing I find out is that I am running NGK plugs which have a higher resistance, and of course are a low heat range. Apparently, Champion plugs have the higher heat range which should be overcoming the oil coating at startup. I have to idle in for about 10 minutes on return trips to the ramp, or longer, which is giving the oil the chance to build up as the motor cools down. It may be the carbs are also running rich, causing oil buildup at low temperatures. First step will be to change the plugs and take a new second set of plugs out. second step will be to runn all the fuel through to get all the mix out. third step will then be to rebuild the carbs so that the mixture is right.

I only plan on having the motor for a year or two as I want to go to a 20 foot welded aluminum with wither a Merc Opti or the Evinrude / Bombardier line. Until then, I will have to spend time getting this thing fine tuned.

Thanks again for the reference to the website, as it helps to understand the operating issues.

Drewski

 

[tykkyt e blue]

Totally agree w removing the VRO!!!! fills your carbs w 150:1 at idle, then you decide to throttle up and for the next few moments, the engine is getting marginal oiling.
I had a 1989 225 Evinrude w hundreds of hours on it - many at 7000 rpm ( Cougar tunnel hull) - ran fine - I HAVE a 1998 225 Evinrude on my alum boat w 560 hrs and its fine too!
Use the OEM fuel pump, just remove the oil side and plug off - you will need to jumper the low oil flow warning. Pre mix w a TC-3 oil at 50:1 and the plugs w be fine. IF you still have fouling issues after that? You have an over-rich jetting condition or weak spark.
A good friend was an Evinrude dealer so this is NOT backyard ideas - pm me if you still have troubles

 

[Gunsmith]

If you are handy to Lordship Marine take it there. They have excellent mechanics.

 

[profisher]

The VRO is a 2 stage pump..it is pumping 100 to 1 at idle and 50 to 1 off idle. Unlike the Yamaha oil pump which is gear driven (proven with years of testing on motorbikes) and is is 100% variable in oiling from 100 to 50 to 1. As engine rpms increase so does the oil injected into the throttle body behind the carbs. As previously noted the VRO mixes the fuel ahead of the carbs and the gas/oil mixture is fed into the carbs...so if you go from idle to wide open..as in pulling a skier, the fuel already in the carbs has to be used up before the richer oil mixture triggered by the full throttle gets to the bearings and cylinder walls.

 

[adrianna3]

Like everyone else said about disconnecting the VRO. It packed it in and killed my motor. When I had it rebuilt, I had it disconnected. Now she smokes all the time. LOL.

Dave