I have a Makita chainsaw model dsc 6421. The saw runs great but I don't get oil to the bar. I brought the repair kit and the pump drive thinking that would solve the problem but no luck.
The hose is clear to the reservoir and the screen is clean. This oil pump seams like a very simple system but I just don't know why it is not working.

Thanks in advance for any suggestions

Mark

 

Take the bar, chain, and chain brake off and run the saw to see if the oil is coming out of the oil channel.

 

I have tried that already and nothing comes out. It seams like it should be a simple thing, that's what is confusing to me.

 

Is the pump rotating off the worm gear? If you take the end screw off the pump you should see the pump turning.

Does the saw have a lot of runtime hours on it?

 

If I have the pump in my hand it rotates but it's hard to see if it is rotating when it is on the saw.

I would assume that it has a lot of hours. I brought it from Home Depot. It was one of there rental saws. The saw starts easy and has a ton of power, just not bar oil.

 

It may be in the pump drive or in the suction side of the pump, as in a leak at a mating, like an "O" ring. If you're using regular bar oil, it's pretty thick and should serve to plug up the smaller leak points.

Try leaving the bar/chain off, then lay the saw on it's side with the bar mount side down. Then fill the oil reservoir and leave the cap loose to let air into the reservoir. See if that gets you oil flow out the bar side after about half an hour.

If you get oil then, tighten the cap and start the saw and see if the flow continues. If it runs for a while, then stops, the venting on the reservoir may be the problem.