HD Makita 6421 - Issue and Initial Thoughts

[Poleman]

Take out the plate, clean out the oil and debris then take out the two screws that hold the Oiler on. You will see there is no hook up for the oil line and that it’s just press seal. Lift up the line and you’ll see the pocket it sets in....put a washer that just fits inside the pocket then put the line back in and assemble. The washer is just shimming up the line for a tighter fit.
I’ve done this with the old black lines and new green that leak with great success.

 

[nwroller]

I got the washer shim installed as recommended(#6 washer for those interested). Pics below. In the second pic you can see the washer in the pocket.

I also replaced the worm gear. Note: if you have the chain brake on putting on the new worm gear and the clutch housing will give you fits. Took me a while to figure out the issue.

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[nwroller]

I’m still leaking a lot of oil. While it’s working great and drill a bit less than before there is still a lot of oil dripping out. At its current rate of oil I’ll go through about 1.5-2 tanks of oil to 1 tank of fuel (best guess). But I do know both were filled at the same time and the oil was much lower than the fuel after about 20 min of use.

Repeatable steps:
- start it and let it warm up for a min or two
- run it hard for about 20-30 seconds
- let it idle with the chain brake off
- watch it drip

My theory: while the chain does not move on idle it is just barely not moving. Perhaps it’s actively oiling on idle. Not sure if the idle should be turned down or if that’s just the way this saw runs or if there is something else going on.




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[dougand3]

Unless the chain is moving - means sprocket is moving the worm gear wings and driving pump.....it won't be pumping oil. You're still leaking.

 

[nwroller]

Unless the chain is moving - means sprocket is moving the worm gear wings and driving pump.....it won't be pumping oil. You're still leaking.

Thanks. Any ideas on how I should troubleshoot? Is it safe to run like that or should I get it fixed before the bar goes into wood?


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[dougand3]

As long as oil goes in oiler hole, it's safe to use. Just messy. Set saw on concrete at idle - go WOT for 2 secs - line of oil should spray in front of and under bar.

 

[nwroller]

As long as oil goes in oiler hole, it's safe to use. Just messy. Set saw on concrete at idle - go WOT for 2 secs - line of oil should spray in front of and under bar.

The bar is definitely getting oil. I get a good oil line when running. The bar and chain are very wet.

So safe to run, just got to figure it the source of the problem. I may need to have a shop take a look


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[Thommo]

I think you should give everything a good cleanup so you can see what you are looking at. If there is any dirt on the hose where it is supposed to seal against the pump, you will have a leak there. One of the hoses could be cut or split in under all that dirt too.