First rebuild- 394xp

[mjwhit]

I was given a dead 394 from a friends part bin, he acquired it for parts and it has been sitting around for a few years. Unfortunately he doesn't know its cause of death. It is in quite a state but as far as I can tell the only major part that is missing is the pull start /side cover.

The saw came in one unit but I done a quick dismantle just to see what I could see. I noticed damage to the ignition coil cable, and the black seal collar that holds the intake spacer was shattered into fragments (the intake collar thing itself seems good so I guess we can rule out air leak there). Also the chain brake band is snapped. Bit of gunk on the top of the piston but surprisingly no damage evident to the piston or the cylinder, so we are going to have to find another reason it was binned. I'm hoping it was just the damage to the ignition coil.

My plan is to use it as a working saw and run it on the Alaskan mill. I plan to put new piston/rings in but re use the cylinder. Replace ignition cable and the seal collar. New gaskets, bottom end bearing seals, fuel and air filters, fuel line. Still thinking about what to do with the carb but I might just leave it for now and work on it later if it causes problems. I dont really feel confident enough to crack open the cases.

I posted here in order to gather input from those more experienced than myself, to keep a bit of record of progress as well as to force a bit of accountability so I can get the project done. I have next to no experience with engine work so hopefully no big mistakes. Any input welcome, thanks.

 

[cuinrearview]

I did one of these in Jan. The only little quirk was setting the seal depths. The tools from Husky are cheap to perform this task.

 

[Jkstihl]

Cash in hand lol

 

[rupedoggy]

Give that piggy a bath!

 

[Deleted member 117362]

I was given a dead 394 from a friends part bin, he acquired it for parts and it has been sitting around for a few years. Unfortunately he doesn't know its cause of death. It is in quite a state but as far as I can tell the only major part that is missing is the pull start /side cover.

The saw came in one unit but I done a quick dismantle just to see what I could see. I noticed damage to the ignition coil cable, and the black seal collar that holds the intake spacer was shattered into fragments (the intake collar thing itself seems good so I guess we can rule out air leak there). Also the chain brake band is snapped. Bit of gunk on the top of the piston but surprisingly no damage evident to the piston or the cylinder, so we are going to have to find another reason it was binned. I'm hoping it was just the damage to the ignition coil.

My plan is to use it as a working saw and run it on the Alaskan mill. I plan to put new piston/rings in but re use the cylinder. Replace ignition cable and the seal collar. New gaskets, bottom end bearing seals, fuel and air filters, fuel line. Still thinking about what to do with the carb but I might just leave it for now and work on it later if it causes problems. I dont really feel confident enough to crack open the cases.

I posted here in order to gather input from those more experienced than myself, to keep a bit of record of progress as well as to force a bit of accountability so I can get the project done. I have next to no experience with engine work so hopefully no big mistakes. Any input welcome, thanks.

View attachment 812046View attachment 812057

Cases are not that hard to separate, just remove everything. Those fuel tanks are easily removed, undo throttle cable, fuel line, av bolts and limiter bolts, should drop right out. Is your bottom end rod bearing tight, it will slide side to side, but you should not feel movement up and down when held straight?

 

[mjwhit]

I did one of these in Jan. The only little quirk was setting the seal depths. The tools from Husky are cheap to perform this task.

Nice tip, thanks. Ill add that to the shopping list.

Give that piggy a bath!

No joking! 20 years of oil, dirt and dust build up.

Cases are not that hard to separate, just remove everything. Those fuel tanks are easily removed, undo throttle cable, fuel line, av bolts and limiter bolts, should drop right out. Is your bottom end rod bearing tight, it will slide side to side, but you should not feel movement up and down when held straight?

Thanks for that. No, there is no up and down movement. To be honest I was more worried about getting it all back together again afterwards, I'm quite sure I could get them cases apart

 

[cuinrearview]

A heat gun or oven and freezer are your friends

 

[mjwhit]

Parts have started arriving. Waiting on new ignition coil to arrive. Other than that It need to order a new chain brake band and starter pull assembly. They were missing when I got the saw.

Spent an hour today cleaning the muck buildup and looking over the saw. Exhaust looks like it has been split and welded back together at some point in time.

Has anyone used the Hyway air filter? Chucked one into the basket when ordering piston and gaskets, but not sure if its the best option to use or not.