What causes excessive oil in the exhaust?

[whoisthatguy]

After testing 3 different oil pumps, and verifying the oil pump adjustment on all 3, the engine continues to burn too much oil. If I give it some gas after warming it up, it then really dumps the oil into the engine. Since there are no electronic features to the 800 vertical escape 2004 oil pump, I can't understand what electrical feature would cause this. Anybody have an idea on this one?

 

[davesilb]

I had a 03 vertical escape and if I remember right I ended up backing the adjustment off about 3/16" off of the set mark to get the oil usage about right. Are you sure the oil pump lever is always returning when the throttle is backed off They have been known to stick from a bad cable or bad routing of the cable? If this happens a couple times when you do not notice it that would put a lot of extra oil into the engine ! Pull the throttle a few times and let off it slowly and watch the lever on the pump and make sure it returns fully and with the movement of the throttle. If you notice any movement that is not exactly with the throttle lever replace the cable. Might be able to get by with lubing the cable well if it does not have internal damage. Any adjustment you make to lean oil usage out should be carefully monitored to use around 1 quart of oil to every 10 gallons of fuel. A little more if running it hard and a little less if just easy trail riding. Good luck

 

[whoisthatguy]

I noticed one oil pump where the lever was not fully returning, due to some hangup in the internal gearing. I have a new cable on the sled. I have concluded however, that the cause of the excessive oil that does not want to burn off, is that I stored the sled with the carburetors still plugged into the rubber boots, so that the oil that leaks through the oil pump whether the engine is running or not, slowly ran into the engine and accumulated in the bottom of the crankcase. Then upon restart, it burns excessive amounts of oil for at least 1/2 hour before starting to clear up. If I stopped the engine before all the excessive oil was burned out of the engine crankcase, and let it sit overnight, then the plugs were fowled on the next attempt to restart the engine. In conclusion, the engines should be stored for periods of more than 2 weeks, with the air box removed and the carburetor pulled out of the rubber boots enough so that oil that is gravity fed into the carburetors, does no drip into the rubber boots.

 

[whoisthatguy]

Surprise ending! Although the engine starts out burning out the oil that dripped into the cylinders via the carburetor, once the engine got warmed up, the smoke got even worse. What happened was that as the engine burned out the oil, it replaced the smoke with STEAM from the cooling system. And one piston cap and cylinder head was almost completely clean since it was being steam cleaned by the coolant. Upon removal of the cylinder head, there was a slight pinch of the inner O-ring outside of the cylinder head groove, that was just enough to allow pressurized coolant to be sucked into the combustion chamber, turned to vapor and expelled with the exhaust. It went through coolant fairly quickly, even though it was just idling on the trailer. Problem finally solved.

 

[BeartoothBaron]

I've run into the pump arm not returning to rest, and I think that can cause over-oiling. The cause seems to be the spring on the pump arm getting weak over time, although the pump may get stickier internally. It's pretty easy to see: just take the air box out so you can watch the oil pump while you work the throttle, and see if the arm always returns to the idle position or not. What I ended up doing was rigging another small spring. It definitely fixed the problem, but it does seem to add to the weight of the throttle pull. I should probably try removing the original spring and see if the add-on is strong enough to do the job on its own.

Anyway, good to hear the real culprit has been found. Washing down the cylinder doesn't do much good for engine life, or performance, I imagine. The coolant level is easy to forget about, but these things do happen. A lot of sleds have never had the coolant changed either. Doesn't sound like that had anything to do with this, but the stuff does break down eventually.

 

[whoisthatguy]

I've run into the pump arm not returning to rest, and I think that can cause over-oiling. The cause seems to be the spring on the pump arm getting weak over time, although the pump may get stickier internally. It's pretty easy to see: just take the air box out so you can watch the oil pump while you work the throttle, and see if the arm always returns to the idle position or not. What I ended up doing was rigging another small spring. It definitely fixed the problem, but it does seem to add to the weight of the throttle pull. I should probably try removing the original spring and see if the add-on is strong enough to do the job on its own.

Anyway, good to hear the real culprit has been found. Washing down the cylinder doesn't do much good for engine life, or performance, I imagine. The coolant level is easy to forget about, but these things do happen. A lot of sleds have never had the coolant changed either. Doesn't sound like that had anything to do with this, but the stuff does break down eventually.

It appeared that a sharp bend in the throttle cable as it's attachment to the carburetor, also causes the oil cable to not fully release the oil pump lever to it's idle position, since they are both connected at one point. A zip tie to the oil reservoir will pull the throttle cable lead up to a higher approach line as it arrives at the carburetor.