OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Chainsaws and Concrete Cutters Petrol Chainsaws and Concrete Cutters Zenoah Chainsaw Won't Start. Help!

There are various things that can lead to the bar oil pump working intermittently or not at all. The ones I've had most trouble with are a split in the oil pickup hose inside the tank, so it sucks air, and a blocked oil pickup filter inside the tank. However if it has ever been run without the pickup filter there's a good chance the pump is trashed, from trying to pump crud.

Another problem I've had is that the oil system discharge port near the rear sprocket, was totally gunked up by old sawdust and dirt. Some oil continued to get through, but it just dispersed into the sawdust and ended up on the ground, not the chain.

I don't recommend pumping solvent with the engine running. It would be likely to score or seize the pump. If you need to clean out the pump after you've made sure it has no problems on the pickup or discharge side, you might consider pumping some diesel fuel through it, mixed with say 10 percent engine oil, by pulling the starter repeatedly with the spark plug removed. Diesel fuel has a small percentage of a special oil in it to lubricate the high pressure injection pump (never run a diesel on kerosene or heating oil - they make decent fuels except that the lack of oil will quickly ruin your injection pump, which is extremely expensive. I think a lot of people have learned that the hard way).