Another 394 project

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MagicJames

MagicJames

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This summer i picked up a 394xp for about $120 bucks, i don't remember honestly... Anyway for christmas my Wife bought me a 395 conversion kit, but somehow she missed out on the actual piston and cylinder so i fixed that this morning and it's currently en-route, along with a piston ring clamp kit. I was out in the garage this morning tearing down the saw, and i got to a stopping point.
A little background I love 1980's 3 wheelers and I've got a few 250R's and 350X's and I'm pretty well versed in building motors, nothing fancy like porting, but i've been known to come up with a few fast trikes.
Anyway, I took some pictures and been good to keep my bolts sorted, as this is my first teardown of a saw, but how does the P&C come off? my allen that i've been using to tear down the saw doesnt fit and i can't see down into the hole to save my life. Destructions on this would be great.
Other things that are gonna happen before the saw lives again,
1) New gaskets all around
2) Install the pulse fitting on the carb
3) mod the exhaust, can't get the bad boy to come apart though :/

what i'm unsure of is should i clean up the transfers and polish up the exhaust?
do all four of the bolts on the exhaust bracket need to be there? it only had one bolt holding it on, doesnt look critical but i like to make sure i don't break anything if it could have been avoided.
I dont know if i should install the decomp or just put a plug in it.
how in the world do i get to the crank seals to replace them?
it's got a low top, should i put a high top with the HD filter?

I know it's lengthy, but i appreciate your time :D I'll throw some pics up when my phone stops being slow
 
andrewhanson

andrewhanson

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This summer i picked up a 394xp for about $120 bucks, i don't remember honestly... Anyway for christmas my Wife bought me a 395 conversion kit, but somehow she missed out on the actual piston and cylinder so i fixed that this morning and it's currently en-route, along with a piston ring clamp kit. I was out in the garage this morning tearing down the saw, and i got to a stopping point.
A little background I love 1980's 3 wheelers and I've got a few 250R's and 350X's and I'm pretty well versed in building motors, nothing fancy like porting, but i've been known to come up with a few fast trikes.
Anyway, I took some pictures and been good to keep my bolts sorted, as this is my first teardown of a saw, but how does the P&C come off? my allen that i've been using to tear down the saw doesnt fit and i can't see down into the hole to save my life. Destructions on this would be great.
Other things that are gonna happen before the saw lives again,
1) New gaskets all around
2) Install the pulse fitting on the carb
3) mod the exhaust, can't get the bad boy to come apart though :/

what i'm unsure of is should i clean up the transfers and polish up the exhaust?
do all four of the bolts on the exhaust bracket need to be there? it only had one bolt holding it on, doesnt look critical but i like to make sure i don't break anything if it could have been avoided.
I dont know if i should install the decomp or just put a plug in it.
how in the world do i get to the crank seals to replace them?
it's got a low top, should i put a high top with the HD filter?

I know it's lengthy, but i appreciate your time :D I'll throw some pics up when my phone stops being slow
The cylinder comes off with 4 Allen bolts that are down the holes. I can't remember the correct size but you are going to need to pick up a longer Allen key to get down there.

The exhaust is welded together I believe so there is no easy way to get it apart. In terms of the bolts, I would replace any missing fastener. They are cheap and just good insurance.

If you don't plan on removing a good amount of material, I wouldn't touch the transfers and exhaust. I don't think you would get much gains from just cleaning them up. But what do I know.

Install the decomp, if the saw is pushing anything over 180 you will thank me for it.

You have to split the crankcase to get access to the seals, there are numerous threads on splitting cases and it can be a little tricky.

I would recommend upgrading to the high top with the HD filter. Those low top filters require a perfect seal with the top cover or else air leaks by and into the carb. Plus a high top saw just looks so much more badass.
 
firefighterwolf

firefighterwolf

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In my very limited experience, the bolts holding Husqy cylinders are usually 3/16 allen heads, while the rest of the saw is 4mm and 5mm.

I believe this holds true with the bigger husky's including the OP's 394. Smaller saws (346/350 series and 254/262 series) are 5mm allen....I think.
 
ELECT6845

ELECT6845

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Yes you need a 3/16" Allen head. Sometimes you need to clean the saw dust out of the bolt heads so the Allen wrench gets far enough down in them or you can round them off. Another thing on those saw is the cylinder might need a gentle tap with a rubber mallet to break it loose once you remove the bolts. Muffler mods are pretty easy. Just take a 288 deflector and add it to the front side of the muffler on the same side as the factory one. You can do this without splitting the muffler, just make sure you get all the metal shavings out of it.
 
marti384

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I just finished up a 395 and I believe that the 394 is basically the same in a lot of regards. You shouldn't have to split the case to remove the seals, just pull off the clutch and flywheel to get to them. Sometimes the allen heads get filled with crud and the wrench won't fit in them. Use a small screwdriver or sharp pick to clean out the heads so that you can put the wrench all the way in without stripping it.
 
srcarr52

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3/16" allen for the cylinder bolts. Everything else is either a 3, 4, or 5mm allen, and there is a phillips head hiding behind the flywheel for the air inject nozzle.

Yes, all 4 bolts on the exhaust support are needed to keep it from rattling off. You'll definitely want the decomp button, especially if you set the squish at 0.020".

machinisttx, I have a 394 on the bench that I'll have for sale within a month.
 
shanedut

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I just finished up a 395 and I believe that the 394 is basically the same in a lot of regards. You shouldn't have to split the case to remove the seals, just pull off the clutch and flywheel to get to them. Sometimes the allen heads get filled with crud and the wrench won't fit in them. Use a small screwdriver or sharp pick to clean out the heads so that you can put the wrench all the way in without stripping it.

This is true to replace the seals all you have to do is pull the seals with a seal puller from the outside(or drywall screw so I've heard). Splitting the cases makes it harder to remove and is not needed. I just did two seal replacements on two 394s I bought a few months ago for 300 bucks. If you are still having troubles with the bolts after trying to clean the head of the screw out take one of the other bolts and try to match a torx head up to it. I find that torx with remove stripped allen head bolts if you can find one that fits tight, you may have to give it a little tap but it will bite and come out usually.
 
mdavlee

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Brake cleaner sprayed down there on the bolts will usually get the crap out of there if you don't have any picks to clean the holes out. Just wear safety glasses and don't look at it when you're spraying;)
 
MnSam

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A little background I love 1980's 3 wheelers and I've got a few 250R's and 350X's and I'm pretty well versed in building motors, nothing fancy like porting, but i've been known to come up with a few fast trikes.

Those are some very impressive machines to start with. I damaged myself several times as a teenager pushing the limit on a 350X.
 
MagicJames

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Oh! And while I'm reading over this i have set squish with some clay or other items when you can remove the head, but since this is one piece cylinder and head, how do i check the squish? And where can I find a selection of base gaskets?
 
rob066

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Oh! And while I'm reading over this i have set squish with some clay or other items when you can remove the head, but since this is one piece cylinder and head, how do i check the squish? And where can I find a selection of base gaskets?
You can do this by inserting a piece of solder to the edges of the cylinder. Roll the engine squishing the solder with the piston and measure. Do in three spots and taking the average. As for gaskets paper bags sprayed with silicone, cut beer cans etc.
 
mdavlee

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You can do this by inserting a piece of solder to the edges of the cylinder. Roll the engine squishing the solder with the piston and measure. Do in three spots and taking the average. As for gaskets paper bags sprayed with silicone, cut beer cans etc.

I check right across the wrist pin for squish. That eliminates any piston rocking that could happen. I will guess you'll be able to go gasket less on it. Most of them have squish over .040".
 
MagicJames

MagicJames

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I tore down the carb and drilled the hole in the cover, but i read that i should replace the diaphragm/pump because it breaks. I took it off and the gasket stayed on the carb, so im not sure if I should replace it or not. Secondly, how should i attach the fitting to the carb? The instructions i got said use Gorilla Glue super glue, not so sure on that one. Lastly, i measured the squish and it was .034 without the base gasket, and the gasket is .019. I figure i'll lose 2-4 thou when I torque the bolts down, so i want to come in somewhere between .020 and .022. With my other projects i can just deck the head and it doesn't mess with timing or anything, so not sure on what to do here with this. Do i stick it in the lathe with a 4 jaw and cut the cylinder down .028 and then cut the sleeve down and taper the edges? some input here would be greatly appreciated.
 
MagicJames

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Been pretty quiet with the new year so i've been out in the garage working.
Got the fitting installed in the carb, used some red loctite and it worked great. fitting is tight and looks good.
I then worked on the base gasket, used some paper wrapping that came with my cylinder it was approximately .003. Talked to a old gearhead who used to wrench on dune buggies, and he told me to spray the paper with some silver spraypaint because it has some aluminum flakes and will make good gasket material. i tried it, looks good was about .004 after i sprayed it twice on each side. Installed it today and got about .035 squish after the bolts were torqued down.
Opened up the muffler to match the exhaust port on the cylinder. I tried to open up the muffler up and i took it out too far, so i'm gonna have to replace it .
Still waiting on parts from bailey's. the HD intake elbow is on backorder :/ so i might run it without until it comes in.
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