Hello
We have noticed that after bleeding the oil pump line three times and after running the machine 15 to 20 minuets and then shutting motor down we are getting air gap right before the barn where line goes ino
carbuerator. It seems if somehow air is getting in the pump and he accumulates at the top of the line between pump and carburetor. Does anyone know if the pin is sized or sheeted or maybe the gears in the pump it’s self or a bad seal or o ring. We’ve tested the rate of oil flow at idle with the pump valve open and get a drop 3-4 seconds but seems like the more the machine is ran it’s getting air in it and oil then not getting to carb. Don’t want it to lean out and suede. Any ideas? Much appreciated.

 

Open the bleed screw on the pump. Hold the pump arm wide open while engine is at an idle for about a minute or so. This allows the pump to bleed any trapped air and pump wide open.Close the bleed screw and hold the pump arm wide open again at an idle. Oil tube at the carb should have a very light dribble of oil. You can remove the line from the carb for a minute or so to check. There were problems on the earlier 96 oil pumps that used a plastic drive gear,but the 97 shows to use the reliable steel drive gear in the parts break down. Item #17. I'd still go through the bleeding process just as a precaution.

 

 

Possible but highly unlike the pump is sucking air. It'd have to seep through the top or at the oil pump o-ring at the engine.What I'd do is get a small plug,block off the injector at the carb. Tie the pump line into a baggie,premix the tank 40-1 and drive the devil out of it for a while. Should be a little oil in the baggie,just not a great amount. Plus not unusual after you kill an engine that oil can back up on the injector line a little towards the pump. That might be what you're worried about. Plus if you premix,don't worry about hooking the oil line back up to the carb. That's how we serviced new ones out of the crate. Factory recommended premixing the first tank along with using the oil pump.Just an aid in break in and also if there were any trapped air pockets from the tank, to the pump and to the carb, the premix was the back up. As an example most people averaged around 5-6 tanks of fuel to two quarts of oil. A lot of people were worried about that and I got that question several times a week. The oil pump is metered at a 50/1 ratio at low or high speeds from the factory. They don't use much.