Hutzl stihl 390 replacement engine question

[a. palmer jr.]

How do these nipples come out???

If you're careful you can drill them out. I think they sell those nipples on ebay, I generally JB Weld mine in..

 

[a. palmer jr.]

You'll probably need to pull the cylinder. They can be tapped out from the inside with a proper size pin punch. Seat the new one with a proper sized 1/4" drive deep well socket and a hammer.

I've tried that on some of them and they wouldn't come out, some of the nipples on them are so loose they fall out..you just never know.

 

[a. palmer jr.]

Do you all put sealer around your seals also?

I have before and on some I didn't, really couldn't tell the difference as long as the sealant goes up to and touches the seal. I coat both the cylinder and the pan but not real thick. I've had best results with Motoseal.

 

[fearofpavement]

I've tried that on some of them and they wouldn't come out, some of the nipples on them are so loose they fall out..you just never know.

Get a bigger hammer.

 

[cobey]

Thanks for the info guys
Hopefully I'll have time to finish
Taking the saw apart, get the nipple
Off the other motor, and get the
Engine pre assembled, vac tested
And in the saw.

 

[MustangMike]

Did not read all the posts, but I did a 029 to 390 conversion with the Farmtech and used the Farmtech rings and decomp and seals w/o any problems. I used the OEM bearings, they were not bad.

I did a muff mod and timing advance. If I did it again, I would plug the cylinder hole, compression was not high enough for a decomp to be useful.

Saw ran good, but not great, I'm used to the pro saws, and it did not quite run like one. For the money, it was good.

 

[Khntr85]

I use dirko, I put it on the seals too....I also skim some on bearings, but it may not matter....I love dirko, but it's all I have ever used....the stuff is flat out tough....I waste some wash time, and have done 20-30 saws with the tube I have now....it's easily got 15-30 uses left....and like I say I waste some each time...

 

[cobey]

Old piston, in the square below
Is pic of the top of the piston, it looks
Bad too

 

[cobey]

Knocked the factory nipple
Out of the old motor from the inside
With a punch

 

[cobey]

I drilled the extra hole and plugged
The decomp valve

 

[cobey]

Pre assembled, I will try to
Start putting it together in a day or two.
I put caber rings in it

 

[BuckthornBonnie]

View attachment 64616
Pre assembled, I will try to
Start putting it together in a day or two.
I put caber rings in it

Good choice.

 

[cobey]

The rod bearing was falling apart
I guess that's where all the metal
Came from

 

[PA Dan]

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.

And what happens when you use the oem screw in that hole? Oh snap! Ask me how I know!

 

[cobey]

And what happens when you use the oem screw in that hole? Oh snap! Ask me how I know!

I used a short 10-24 screw, it seems
To work

 

[Khntr85]

Ya I forgot and broke a screw off in the kill switch wire hole in the damn cylinder the other day....

I forgot and don't know if any one said it, but I have 4-short screws that I use strictly for putting the engine together and letting it set-up over night....I use them in all the Stihl clamshells....if I remember correctly the ms170 and MS180 are the only saw that have their own separate "pan screws"....


Let us know how it goes....I just got a 390 rebuild done last week or so, saw runs good, I got a heap piston and cylinder in it too....

 

[Khntr85]

I also run atleast a tank of gas threw all my rebuilds....I just like to make sure if something is goin to happen that it happens to me not the person I am selling it to....

 

[fearofpavement]

I also run atleast a tank of gas threw all my rebuilds....I just like to make sure if something is goin to happen that it happens to me not the person I am selling it to....

I never sell any saw without putting a few tanks of fuel through it. I want them to make a one way trip. I especially try to run rebuilt saws a lot to test them. Because I'm always "testing" a saw, I rarely get to use the saws in my line up. Just haven't had that much stuff to cut the last couple years. I cut a lot of cookies but that seems like a waste to me because I'm burning fuel, putting wear and tear on saws and getting nothing for it. Sorta like using a treadmill.

 

[cobey]

Anyone ever fix coil holes
In the plastic case?

 

[MustangMike]

No, but if you fill it with Loctite PL Premium, let it dry for 2 days, drill & tap, I'm sure it will be stronger than new.