Any experts on 394xp chain brakes?

[Jon1270]

Trying to finish up a 394 project, and I'm stuck on the chain brake assembly. It's not the usual problem of compressing the main spring; I've figured that out. I still can't get it to work.


This saw had been scavenged for parts before I got it, so about half the brake mechanism was missing. I placed my parts order just going by the IPL. While struggling to get it assembled, I realized that the spring I got that's supposed to fit inside the brake handle does not match the IPL. Here's a screen grab from one parts retailer. Everyplace I've checked online has this same discrepancy, with the part they're selling not looking like the part shown on the IPL.



Can anyone confirm what this part should look like on a 394? This is the first time I've messed with this style of brake mechanism so I'm not too sure of myself, but the spring I got just doesn't seem workable. 'm tearing my hair out here. Thanks for any insight.

 

[Jon1212]

Here is a picture I found online of the exposed assembly. It may help you in the process.

I have seen both types listed on the Interwebs, so they must both work.

 

[Jon1270]

Here is a picture I found online of the exposed assembly. It may help you in the process.
View attachment 485107
I have seen both types listed on the Interwebs, so they must both work.

Thanks, Jon. I think the spring needed might depend on the type of hand guard used. On mine, the shape of the cavity that the spring fits into makes that relationship of parts impossible. Fully inserted, the straight leg of the spring might be in an okay position, but the curved leg of it protrudes well past the cross-pin, and gets trapped between the cross-pin and the finger spring.

 

[Jon1212]

Any chance you can twist the loop to the other side?

 

[RedFir Down]

Years ago I encountered this same issue. Off hand I cant remember how I fixed it (suffering from CRS at the moment).
Im pretty sure I have a picture on an old phone at home I can post later. If not pull mine down.

 

[Jon1270]

Any chance you can twist the loop to the other side?

Haven't tried, but being a spring I don't think that would work unless I annealed it, modified the shape, and then redid the heat treating. I've made springs before, but I suspect finding the right part would be easier.

The spring shown in the IPL looks very similar to the one used on the 262. I happen to have one of those here, and might try a swap...

 

[cus_deluxe]

i recently put a new brake band in a 395, i assume its the same assembly but i could be wrong. hard to exactly see the arrangement in jonathans above post, but the straight end of the spring has to go in the little gap between the legs of the forked spring and the forward end of the knee joint (if that makes any sense) are there different handles for wrap handlebars or something?

 

[Jon1270]

i recently put a new brake band in a 395, i assume its the same assembly but i could be wrong. hard to exactly see the arrangement in jonathans above post, but the straight end of the spring has to go in the little gap between the legs of the forked spring and the forward end of the knee joint (if that makes any sense) are there different handles for wrap handlebars or something?

Yeah, I found a few discussions of how these go together, including the insertion of the straight leg into that little gap at the bottom of the finger spring. I don't think that's the issue.

I'm just guessing that there are different brake handles, as that would explain the change in spring design. This is the only 39* I've had. I suspect it's a fairly early version -- 1994 going by the serial number, if I'm interpreting it correctly -- but it's slightly hard to believe that because it's in such nice shape. Physical evidence suggests someone got it hot and smeared the piston on about the second or third tank of fuel, and then just put it on the shelf and stole screws and springs from it once in a while; most of the saw is in near-mint condition.

 

[Jon1212]

Yeah, I found a few discussions of how these go together, including the insertion of the straight leg into that little gap at the bottom of the finger spring. I don't think that's the issue.

I'm just guessing that there are different brake handles, as that would explain the change in spring design. This is the only 39* I've had. I suspect it's a fairly early version -- 1994 going by the serial number, if I'm interpreting it correctly -- but it's slightly hard to believe that because it's in such nice shape. Physical evidence suggests someone got it hot and smeared the piston on about the second or third tank of fuel, and then just put it on the shelf and stole screws and springs from it once in a while; most of the saw is in near-mint condition.

I understand your frustration with the assembly. I've put together a couple of those that were in pieces, and it always reminds me of trying to solve a Rubik's cube while under the influence, and having numb fingers.

Sounds like a really good saw deal, though.


This is a 2002 I picked up with a roached piston for $20. Under the grime it was as you can see, very low usage.
I just finished it last night.

 

[Jon1270]

Nice one.



Doesn't look 22 years old, does it? The air filter cover, one of its springs, the decomp and one recoil screw are new. Everything else you can see is original.

 

[cus_deluxe]

wow that thing is sharp. well hopefully you get it figured out, as repeated above they are a bugger for sure.

 

[RedFir Down]

This is where the spring is suppose to be when you put the brake flag on the cover.
Sorry for the terrible pictures, hope it gives you an idea.

 

[turtle561]

looks like the brake on my late model jonsered 625 ii. the main spring and band were missing. drawing shows orientation of its parts, it is working fine now.

 

[Jon1270]

This is where the spring is suppose to be when you put the brake flag on the cover.
Sorry for the terrible pictures, hope it gives you an idea.

Thanks. That's definitely a different hand guard from mine, though your spring looks like what I received. Trying to put that spring in my handle just doesn't work. The curved leg is so long that it sticks out past the cross-pin even when the spring is bottomed out in its cavity. I think I'm going to have to track down the other spring, or spring for a new handle.

 

[Jon1270]

looks like the brake on my late model jonsered 625 ii. the main spring and band were missing. drawing shows orientation of its parts, it is working fine now.

Looks like that spring was used on a lot of Jonered models, including the 2094 and 2095. And it's still available. Hmmm....

 

[RedFir Down]

That's definitely a different hand guard from mine

Its for a 395. If i remember right the 394 and 395 use the same parts here. can you post pictures of your spring and brake flag?

 

[Jon1270]

Its for a 395. If i remember right the 394 and 395 use the same parts here. can you post pictures of your spring and brake flag?

Sorry for the delay. I checked more closely, and the brake handle on my 394 is exactly the same part as the one on a 262xp that I have, PN 503 72 75. The one from the 394 is a little beat-up inside the cavity, like maybe someone else struggled with it before I got it.

Here are pics of the new spring, along with the one taken from the 262. The legs of the new one are about half an inch longer. Also the entire guard, and views of the cavity with each of the springs installed.



It's much easier to get the assembly together with the 262 spring, but I still haven't been able to get it operational. I also had to replace the main coil spring that actually tightens the brake band. I'm starting to think that might be the wrong part, too.

 

[turtle561]

i had to cut the main coil spring down on the jonsered 3 coils or so to 3.330" long. it works fine now.

 

[Jon1270]

i had to cut the main coil spring down on the jonsered 3 coils or so to 3.330" long. it works fine now.

How did it behave before you cut the spring down? If I assemble mine without the main spring then the mechanism works fine, pushing the knee joint back and forth just as you'd expect. As soon as I install the main spring, it becomes impossible to move the lever back to release the brake; it's as if the mechanism locks up.

 

[turtle561]

i couldn't get the spring in initially, it was too long. in doing a search i found a blog for huskys where they said the spring should be the 3.330" long. that looked more like it it & worked when i cut the new one down.