982--gas in oil

john hall · #1 10-15-2014, 09:13 PM

Thought about posting under the Onan section but there isn't much traffic there. Figured this may also apply to some of the later Cadets with Kohlers. Anyway if the moderators decide it needs to be moved, no problem here.

On to my problem. My 982 uses a little bit of oil, not enough to smoke, just needs topping off after running for an hour or so. We always check the oil before using. When I saw it was slightly over full, I knew I had trouble. You could really smell the gas when I drained it. I installed a fuel filter a couple months back ahead of the fuel pump. I pulled the top of the carb and found a little bit of debris, really small stuff. Do you suppose it got by the filter or is something in the pump turning loose? The fuel lines are new. Cleaned the carb out and have run it for about an hour. We also installed a fuel shut off after the filter. Dad was the last to use it before I found this problem. Don't know if he left the gas on one day or not. Is it possible the engine is running too rich (or the needle not sealing) and not smoking but allowing the fuel to go by the rings, or is this just a case of we left the fuel valve on and the needle wasn't sealing?

J-Mech · #2 10-15-2014, 10:21 PM

At the end there, you kind of repeat and then it gets unclear. If the needle valve isn't sealing, it will leak gas into the intake, into the cylinder, past the piston and into the crankcase. If it is a fuel pump issue, it will leak directly into the crankcase. Usually, a leaky needle valve (seeps) doesn't affect it running, as it burns fuel faster than the small leak. (Make sense?) Now, if the needle is stuck all the way open...... that's different. Either way, gas in oil = BAD. You don't want to deal with an internal failure from thinned oil. My advice, head it off at the pass. Replace both the fuel pump and rebuild the carb. Either way, you kick the problem in the rear.

john hall · #3 10-16-2014, 06:15 AM

Didn't even think about the pump leaking! I'll look into it. You did follow me about the needle valve, I didn't think it could leak enough while running to bother unless it was literally pouring fuel in. Well, time to find some reasonably priced Onan parts.

Tony h · #4 10-16-2014, 08:15 PM

It's not only Possible, it's probable that the Needle seat isn't doing it's job. Just one of the many hazards of Ethanol Gas.
I bet dad didn't turn off the new Shutoff.
You can buy new seats and needle valve if you want to go crazy OR just shut off the new Valve just before turning off the engine.
One of the reasons I got my Cub from the P.O. was that the gas leaked into the Cylinders on it's way to the Oil Pan and caused hydro lock. When I got it, the crank case was full with gas and oil.
I have fixed many neighbors and friends lawn mowers , snow blowers etc just because ethanol gas had paid it's toll on the rubber parts as well as rusted up the Bowl area of the carb. Politicians and the Agricultural Lobbyists have caused this 'crime' and I can't buy Non ethanol where I live to fight this Carb killer.
The particles in the Carb., did they look almost metallic/shiny or almost like salt? Ethanol gas will also cause the Bowl to deteriorate. If you take the bowl off, look close, the bowl might look pitted inside.

J-Mech · #5 10-16-2014, 08:35 PM

Ethanol DOES NOT pit metal. If the bowl on your machine was pitted, it was from the WATER that is attracted to the alcohol in the fuel. I've said this a million times on here, and I'll say it again. I run ethanol blended fuel in all my cubs. I NEVER shut the gas off on any. Just dug one out that had been sitting for at least 6 weeks. Gas was on, no leaks, it was fine. For the record, not all needle valves are rubber tipped. Some are all brass. Ethanol has it's problems I don't disagree. It does eat rubber that isn't made for it. But, the manufacturers are aware and new products that are compatible are out there. More all the time. You really don't need to push blame to ethanol where the actual problem is improper general maintenance and mostly older non-compatible parts.

Tony h · #6 10-16-2014, 08:48 PM

Exactly.
Ethanol draws in moisture. The alcohol Kills the rubber parts in almost all carburetors since only the very newest ones are starting to fight this mess.
The water absorption rusts carburetor internals.
Very few carbs are metal needle with Brass Seat. almost all have rubber on one or the other.
Stihl chainsaws will not warranty a saw if they suspect Ethanol gas.
Manufacturers are popping up "Real Gas" "True gas" for a reason.
anyone with an older car ( pre 90's) ask them about their troubles with a car that sits more than 6 months since ethanol has entered the picture.
People used to let their engines sit and end up with Varnish in the carb, now it's rust, gooy gas lines and and none seating issues. I have 5 fairly new chainsaws, 3 fairly new snow blowers and an old Cub cadet because people tossed them out after they wouldn't run. Finds like that used to be far and few between. compared to pre ethanol days, ask any mechanic and see what a tabockle this gas is. It's Great for the small engine repair guy and the guy that sells rebuild kits. What it does for me is make a ritual of starting up the antique cars more often than ever before