Old 395xp - at what point do you do heavy maint/light rebuild?

[davidwyby]

I’ve had the saw well over 10 years, bought used off ebay from the PNW, likely retired logging saw. Mostly sits and has been neglected but that’s gonna change. A few years ago I let two of my employees use it and it burned up. Don’t know why. Saw shop rebuilt it and it’s mostly sat since. Just got back from same shop for carb kit and other stuff that had dried up and fallen apart from desert heat and ethanol. They forgot to change the shutoff wires, they are shedding their insulation. I’ve decided to do my own work (I do all my own vehicles, other people’s and run a machine and welding shop). Saws seem comparatively easy. Anyway, gonna vac and compression test, all that, but I got to thinking, maybe I should do a heavy maintenance/light rebuild. I’ve found a bunch of screws and little things missing or broken. Making an order from @Spike60, want to see what else I should get. Gonna tear into it more tomorrow. Replace the crank seals and...?

@huskihl piston streak

 

[blsnelling]

You for sure want to pull the cylinder and check out that streak. That's not good. Best to catch it early.

 

[XP_Slinger]

X2 on checking that streak. Looks like it is the beginnings off transfer but maybe you’ll get lucky and it’s just a carbon streak. It doesn’t look like it too me but here’s hoping luck is on your side.

In addition to crank seals I would change all the rubber bits like the fuel line, pulse line, check your intake closely for cracks and replace if you’re not 100% confident that it’s good. Youve already identified that you’re having dry rot issues so I would replace everything potentially affected by your dry climate. These small rubber parts are very cheap insurance to protect your rebuilt saw. Keep us posted on that streak.

 

[angelo c]

Yup...that jugs gotta come off. I'm betting a circlip was eaten....hope I'm wrong but it looks deeper then carbon from here. Look in the case bottom for bits of something as well.

 

[huskyboy]

Check how much it’s worn on the piston intake side when you pull it apart. If there are no machine marks left and it looks worse than the exhaust side, I’d get a meteor piston, they are good pistons, about 38$ from @Definitive Dave. I’d replace fuel/impulse line/fuel filter/crank seals/base gasket and carb kit. I’d use oem for those parts. Make sure the bearings/crank spin smooth too. I had a 394 with a bad carbon score on it worse than your picture and it was from build up in the exhaust port flaking off, replaced the piston with a meteor and the seals started to leak shortly after that due to age. Replaced them and the saw runs great. It’s cheap insurance to do all those little items while you have the saw apart. You can remove the old seals with a small screw driver/pick carefully prying up under the rubber with a twisting motion. Be careful not to scratch the cases. Make note of the depth of the old seals (take a picture for reference), and drive the new ones straight in (take care not to get them crooked) with appropriate size deep socket. Don’t have to get them exactly where the old ones were, but don’t want to drive it into the bearings or too shallow. I use a rolled up soda can and oil to get seal over the lip of crank. Everything else is comparatively easy to do.

 

[davidwyby]

I’m wondering if maybe when the saw shop worked on it last time, a piece of debris got in it. Which would partly be my fault cuz the thing was so filthy. Use it a little, put it away, repeat a few times and yuck, this thing is a mess! Covered with WD soaking overnight now, gonna go blow/brush it off and see what’s up.

 

[davidwyby]

Seal lip didn’t look right....yep.

 

[Adirondackstihl]

Never built a 395, but looks to me like the crank isn’t centered or the seal was never pressed to proper depth

 

[huskyboy]

It looks like it isn’t deep enough. It should be a tad deeper over the lip. It probably contributed to it failing along with age.

 

[davidwyby]

Makes me wonder if it would seal if I set it deeper. Don’t mind replacing but don’t want to get into cases/crank.

Crank has no play in any direction.


Cylinder looks good. Just starting to show some wear lines on exh side, honing lines still visible.


Piston doesn’t look bad. Looks worse in pics. Can barely, barely feel one scratch in the middle of the mark. Polished a little with Brillo. Intake and exhaust both still have 50-75% of machining marks.

 

[KZ1000]

Old 395xp - at what point do you do heavy maint/light rebuild?
When your ms170 out cuts it.

 

[KZ1000]

Looks like a little carbon went thru, nice otherwise. Ring it and run it.

 

[davidwyby]

Forgot to mention compression was 150. What should it be? It has very little hours since rebuild. Like maybe 1-2. Kinda doubt if I need to bother with rings. There’s a little carbon on top of the piston, not sure if it’s enoigh to flake.

At some point, I should probably quit inspecting...

 

[huskyboy]

I replaced a much worse case half that looked like this fairly recently lol... Its your choice but those small cracks can either be welded up or would probably last a while before being unusable. I’d lightly sand the scuff on the piston with very fine grit and re ring it. Also replace the leaky seal and call it a day.

 

[davidwyby]

Dangit man. Just took my wife out to the woodpile to let her try a saw for the first time and now the 2139 is acting up. Racing a little after the cut, high idle flywheel up, low idle clutch up. *maybe* that chafed spark plug wire I taped the other day, but I have a feeling I’m putting crank seals in every dang saw I own...and I have a sizable job for them in the works.

 

[XP_Slinger]

Dangit man. Just took my wife out to the woodpile to let her try a saw for the first time and now the 2139 is acting up. Racing a little after the cut, high idle flywheel up, low idle clutch up. *maybe* that chafed spark plug wire I taped the other day, but I have a feeling I’m putting crank seals in every dang saw I own...and I have a sizable job for them in the works.

Holy smokes man! At least you’re catching them early.

 

[davidwyby]

I like saws...sometimes. Ha!

 

[davidwyby]

Coil didn’t help. Hoping for intake boot instead of crank seals. Same as a 338xp, put together different than “usual”, reputation for being difficult.

It’s an ‘08 that came from a tree co. I’m guessing that is getting old in saw years, eh?

 

[davidwyby]

This doesn’t seem like a big deal, or am I missing something?

 

[huskyboy]

This doesn’t seem like a big deal, or am I missing something?

That won’t hurt a thing. That holds the carb limiters in place or something along those lines. Looks like someone already defeated them.