Hutzl stihl 390 replacement engine question

[cobey]

I ordered a 390 kit for a shot
290 stihl I got super cheap
From a guy I work for.
It's just gonna get sold
When it's done , but should
I put a caber ring in it and toss
The Chinese ring. What do you
All think?

 

[Dub11]

I ordered a 390 kit for a shot
290 stihl I got super cheap
From a guy I work for.
It's just gonna get sold
When it's done , but should
I put a caber ring in it and toss
The Chinese ring. What do you
All think?

I would and if your doing that swap the circlips from the 290 there a nother week point

 

[67L36Driver]

I would and if your doing that swap the circlips from the 290 there a nother week point

Definitely salvage the wrist pin retainers from the 290.

Piston ring I wouldn't bother with on a 'flipper'.

Note: You may have to use the Chinese crankcase bolts as the threads are enuff different than OEM.

 

[67L36Driver]

Also the tapped hole for the coil ground wire at the cylinder has caused trouble.

Under no circumstances would I use a Farmertec decomp valve.

 

[Dub11]

I forgot about that. And some people drill a small hole on the lower exhaust mount saying thats a hot spot. I can post a pic in the morning Iam at work now

 

[cobey]

I have heard about the wrist pin
Clips, what to do with the coil ground screw threads? I think I have heard
About the hole in the muffler
But don't remember where to put it.
I should have caber rings for it in stock, i wondered about how long the hutzl
Rings would last (I didn't want it coming
Back with lo compression)

 

[Dub11]

On the coil screw the hole is not deep enough or tapped all the way and the hole is on the block casting in between the fins on the lower exhaust mount.

 

[cobey]

On the coil screw the hole is not deep enough or tapped all the way and the hole is on the block casting in between the fins on the lower exhaust mount.

Cool I'll check it when it comes in

 

[Dub11]

And check that impulse nipple sometimes there lose or leak.

 

[Dub11]

Didn't you happen to say you were working on a 346 lately?

 

[cobey]

Didn't you happen to say you were working on a 346 lately?

Ya it's on the bench, been busy this week.
It needs a rim , a test, and tune..

 

[Dub11]

Did you replace the piston in it? I asking because I have a Makita 520i and having trouble finding a replacement piston so I see were the 346 is 44mm and was wanting some measurements off of it.

 

[Khntr85]

I know, I know, but use the hutzl stuff....I just rebuilt 390 and used the hutzl stuf, runs great.....I know a lot of people have mentioned the c-clips, I have never had a problem yet, I am sure I will eventually, but not yet....

Like another guy said the decompression valves are 100% bunk, they won't even close once the saw is started.....


I know some say use OEM this and that, but if you are trying to rebuild and sell saws, to make any money ou got to try the "Chinese" stuff....he'll once you put your couple hours time in a rebuild, the profit margin drops .....

 

[Khntr85]

Oh and does anyone know were I can get one of these...it's the part that covers the decompression valve hole...the saw I just rebuilt does t have the piece and I can't find a PN on the IPL.....it's very strange

 

[Czed]

I've built many saws with all chinese topends i prefer the oem wristpin bearings and circlips but i just cut off some of the g on the chinese one's no failures yet in dozens of saws.

 

[fearofpavement]

Having built a bunch of the 1127 series saws with Huztl parts I'll add my findings. 1. On the ground screw hole, I use a short 10-24 sae screw. Fits perfectly. That hole is not tapped to fit the Stihl standard screw. I've talked to Huztl about it years back already but as far as I know, no changes were made.

2. On the circlips, the OEM ones are smaller (diameter of spring metal) and while I think they would stay in there, they aren't really a good fit. I trim part of the ear off the Farmertec supplied ones and that seems to work. I did have one of these ears break off once and ruin a cylinder. It happened at pretty low hours (less than 10)

3. On the piston rings, I've always used the Farmertec rings with good success.

4. On the decomp valves, I don't have any input on those because I've used few of them. I plug the decomp hole. Rarely do I get a saw in that had the original decomp setup.

5. Never had an issue with any of the bearings.

6. These engines are prone to leak after assembly. I always build them up outside the engine housing and pressure test them the next day before install. A common leak point is around the cylinder cap (clamshell) retaining bolts. Not sure why. I always dob some sealant in there when installing the engine.

7. Make sure to trim the limiters on the carb when it's apart. If you are upgrading an engine with just the two small holes in the muffler, it may hardly run without a muffler mod. This saw, probably more than any others I've worked on, NEEDS a muffler mod. They're easy and lots of options.

 

[BuckthornBonnie]

I've done several and will use em again. But...

1. Had a pto bearing failure using farmertec bearings. That may have been related to a slightly loose fitment of the bearing in the AM engine pan. On the next build up I used Nachis and an oem pan. It didn't completely fail... noticed it during routine maintenance.
2. I use Cabers. The farmertec rings are probably ok but make for a tricky install (easy to break).
3. Use the best quality sealant and be sure to degrease everything before applying. Wash and blow out the p/c, too.

 

[BuckthornBonnie]

Oh, and careful on those bolts. Theyre not t27 heads (allen). I stripped one out once and drilled it out, not fun lol.

DDave had extras on ebay.

 

[Dub11]

Heres those holes I was rambling on about

 

[cobey]

Thanks for the input guys,
I have heard most of this
But kinda wanted current info.
I want this saw to work good
For whoever buys it.
I don't want to set someone
Else up to fail. They probably
Don't have 30 other chainsaws
To use