Aftermarket Oil Pump Drives

[jk14]

Thanks for the info, saved me a headache. I was about to order a few aftermarket worms. Called the stihl dealer and the are only $5 so I'll stick with oem on the worm gears for now. BTW. They come without the drive tang as most already know.

 

[Lightning Performance]

Any changes on these pump worms?

I stripped two on modified pumps. Switch to OEM and it still munched the gear. Built an OE pump with HO gear now running the AM worm. So far so good. It will mill. Time will tell. Hyway worm 1122.

 

[MG porting]

I can only speak for my experiences with parts.......but these AM drives just don't seem too good, they strip, melt, etc...

So, what good are they? Well, the drive arm seems to be fine, so I use just the drive arm, and swap it onto an OEM gear.

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They melt because the arm spins on the worm gear itself that's just what I've experienced anyways and sometimes the slot on the drum isn't deep enough so that will put fores down on the driver arm but again that's what I've experienced.

 

[MG porting]

Any changes on these pump worms?

I stripped two on modified pumps. Switch to OEM and it still munched the gear. Built an OE pump with HO gear now running the AM worm. So far so good. It will mill. Time will tell. Hyway worm 1122.

All I can tell you is check everything on you're pump side everything is more less got to be spot on.

 

[Lightning Performance]

All I can tell you is check everything on you're pump side everything is more less got to be spot on.

Been there done that many times. The pumps are easy. Too much ramp on the gear killed that one, opps. It needs a roller Too much lift too fast . More like the "custom cam" that killed the lifters my bad.
I just happened to be testing these AM ones at the same time in 1122 saws. They work just fine in 361 saws if you close the hole up a bit in the spring. The HO pumps slip right there if you forget to close the loop a bit. Then they melt. Randy told us that in this threads beginnings see page #1

 

[dmb2613]

I had 3 to fail in a row, I found the problem, the AM ones were too tall . when you put the clutch on it would almost lock up
Was very tight, I deleted the washer that goes between the clutch and the worm and they worked. I ended up sanding them down on a flat sander so I could use the washer. Problem solved . These were 029s , 1127 series saws. I no longer buy the farmer tech ones . I use used or new oem ones now. Some things from China are OK to use some are not. The best thing from China is the Plugs to delete the Compression releases. I have had good luck with the Cross pop up pistons, but they seam to be the same as Farmer tech.

 

[Lightning Performance]

Anyone running the aftermarket pumps?

 

[MG porting]

Anyone running the aftermarket pumps?

I'm running two of them right now hoped them up so far there doing good.