g395 + hyway hackorama

[huskihl]

There's a washer in there... 27.80mmx15mm, 1mm thick. It seems close to a reference I found online that indicated OEM is 28x15mmx1mm. Really hoping its just an out of spec oil pump gear? I have another AM oil pump and worm gears on order, but will be a few days for them to get here. It will be interesting to compare the bunch. I also ordered the OEM shim/washer for giggles.

Aftermarket worm gears are known to be soft and strip often. I would try an OEM worm gear and see if that fixes your problem

 

[Nutball]

I always spin the piston gear part of the pump to make sure it rotates with very little resistance and has no catches. I have found some that can be quite stiff and need cleaning, modification, or replacement. Even OEM pumps can be hard to turn sometimes. It might not seem all that hard to turn expecially considering the leverage of the worm gear, but it puts that much more wear on the worm gear wearing it out quickly.

 

[buckin-wood]

Pump had a fair amount of resistance before I took it apart and cleaned out all the brass colored gunk. When I put it back together it definitely turned more freely and much smoother for sure.

Looking at a parts diagram I see that the OEM pump has two washers that sit between the spring and piston. There was definitely only one washer in the FT pump. Could this be adding enough added friction to cause it to wipe out the worm gear?

 

[Nutball]

It's hard to tell. Sometimes it's the really subtle stuff that makes a huge difference. A second washer could reduce friction. They don't do a good job of cleaning some parts: leaving magnesium grit in the bearing pockets, and aluminum grit in the oil pump. I have found very sharp edged washers in a 372 oil pump. I like to make sure the spring is inserted in such a way it doesn't try to stop the rotation like if the pump was rotating opposite the direction the spring is coiled. I also like to polish where the flow adjustment screw rubs, if needed, and grease the worm gear. A dry lube may be best especially because grease can dry out and get very sticky on the shaft, which probably is not good for the worm gear bushing.

 

[qurotro]

The OEM worm gear is plastic. FT did a brass one?!

 

[Nutball]

And it still stripped!

 

[buckin-wood]

hyway pump + no name AM plastic worm gear and oem washer... got a tank through the saw and no noticeable signs of wear on the worm gear. I test fit an OEM worm gear but it was really really tight. It grabbed the crank so tight that it would turn the motor over if I tried to turn the pump by hand with it. None of the other eight (yes 8) worm gears I have fit this tightly. The FT brass gear was really loose compared to the others. I'm not sure sure who actually makes the plastic AM worm gears I got, I sourced a few from two different sellers and they all look identical to me. Interesting the threads on AM gears are sharp while the OEM worm gear has somewhat rounded profile threads.

Sadly I had the coil cut out abruptly coming out of a cut, would not restart. Definitely not vapor lock or fuel delivery issue. I let it sit a bit it and it fired up and ran a bit longer. I'll swap the coil out and hopefully that will be the last gremlin? My gosh this whole thing has been pretty comical... the only redeeming quality is that it pulls something fierce when it does run. I'd almost consider a second one as a backup. lol

 

[slackinoff]

Sometimes these saws are trouble to get right. Once you get it sorted I bet it will be trouble free. My 440 kit saw had a few troubles but has been solid since then.

I really want one of these 395 kits for Christmas!