Stihl 034 is on my Bench

[float89]

Hello All. Newbie here. (I even Posted this in the milling forum... Reposted over here) Great info, I find myself coming to this site all the time. Figured I might as well sign up and join in.

I have been given an old Stihl 034AV by my dad that needs some serious attention.

GOOD:
- Holds Gas
- Brake works
- Bar's straight
- Pull cord returns beautifully
- Turns over
- Complete Saw

BAD:
- Top end is smoked
- intake side looks OK but exaust is another story
- "oil dust" is hard packed and everywhere
- Probable oil leak (still has oil in it but seems oil is everywhere)
- missing a chunk out of the bottom of the alluminum clutch cover.


I tore into it basically down to the case. Jug/Piston and crank seals are on order. I went with the larger 036 (48mm) set up as that basically seems to be a no brainer. I cannot seem to find a correct clutch cover on ebay in usable decent shape. Can anyone tell me if all the variations in clutch covers work on everthing that ebay says it will? The listing have a range of models but some look similar some dont. I see a lot of them dont have the chain adjustment hole so thats a red flag but even some of the other ones just look a tad different and some are plastic which i dont really want either.

Currently have been cleaning it up the last few nights as I wait for parts but I dont really know where to draw the line on putting parts into it. What are the "just do it becasue its worth it while I am in there stuff". Fuel lines and the oil feed (post pump) line seem ok and not hard and brittle. The oil line from the tank to the pump I honestly dont even know where to begin with that one.

I got it because I will be heating with an OWB this next winter and I hope to use this saw as my main grunt (first "big" saw). I know it has potential and do think it is worth putting some money in it. While I have time I just want to make it's right and set my self up for as much success as possible.

Last thing is chain. I need to get a new chain and dont really know whats best. I believe the bar is a 20" 3/8 stihl. open to any suggestions on chains.

Thanks!
Tom

 

[BuckthornBonnie]

1125 part # clutch cover would work. Is your saw a side-tensioner? Some were front. Most AM covers are decent.
OEM cylinder with oem or Meteor piston is preferred. I have 4 yrs on a Hyway 034/036 but that’s not the norm. We also got 4yrs on Tecomec.
New lines- oem Fuel (may need to upgrade to 1127 line by increasing tank hole... 1119 “straight” line does work, though) impulse line is conventional Stihl line but any correct ID would work.
The oiling system will need to be checked. Remove the clutch if ya didn’t already. These have an oil line that can get cut and leak oil.
46mm- we like 18” 3/8 chain.
48mm- 20” 3/8.
The smaller top end can handle the 20”, though.

 

[BuckthornBonnie]

Oil drive tang should be intact and not worn. Oil pumps rarely fail but can.
Tank vent- tower style? Good vent.
Master control spring can wear- if it doesn’t turn off right away replace.

AVs have a weakspot at the end of tank. The knob style can tear. Aftermarket avs are ok for this series.

Check bearings and crank for play. Any play is bad. Hard used 034/036 can hammer the bearing recess in the case (case would be shot).
Coils rarely fail, but the plug lead can get crispy and break during teardowns. New plug for sure- ngkbpmr7a
There were some upgrades to muffler screw length, recoil, etc. over their run. Get an ipl off the manuals thread or google. Degrease muffler screws before reassembly.
The paper base gaskets are ok, but I use loctite 518 as insurance. Future series Stihl saws use metal gaskets.
The muffler could be pretty open so just clean and blow out everything. Swiss cheese cover?

 

[Evan]

Wheres your photos. I drug this one out of a echo dealer Monday or tuesday

Ill see how the normal sprocket cover fits.

 

[float89]

 

[float89]

Thanks for the info overload Buckthorn!


- I would like to stay with the aluminum on the clutch cover. There are a few on ebay (very used) but not sure about the back end plastic insert area. Mine seems to have just the one long guide but appears as though maybe at some point in its life another triangle piece?

- It is indeed side tension. Would this indicate any range of years? I have no Idea what year this thing is?

- Fuel lines look similar to ones I find online with the S bend and ribs. does this mean i have the newer line Diameter?

- Oil line that feeds the bar feels good and soft with no cuts or leaks. The line from the tank to the pump (with the bevel type contact connection) I am not able to unhook it and even see it really. though I haven't looked into it real hard

- oil drive tang as you can see has definite wear. Is this not normal? I was thinking about ordering a replacement but wasn't sure what is "normal" wear?

- What is this weak spot on the end of the tank? Do I have this Knob style tank?

- Crank Bearings feel nice and tight. I have the flywheel and clutch off also because of the seals to go in.

- Do you use the loctite on the paper base gasket?


Hopefully the pics paint a better picture of things. I did notice that my pull cord says 340 on it as Evans just says Stihl. We have the same tag on the top with the 034av. Again, any of this indicate a yr range?

Thanks guys.

Tom

 

[BuckthornBonnie]

Tbe weak spot isn’t the tank, it’s an av mount that connects the tank and case... known to tear there. No biggie, though.

Ms340 recoil or top covers could be replacements; this series is fairly old and that saw may have been wrenched on before. Your dealer or someone here could run the tag number to give you an idea.
Should be the newer “S” style line. Get the larger oem filter for it (same as 064-660).
Hard to say on that tang from the pic. I’d probably replace it. Worm gear look ok? The tang can be separated from the gear but your dealer can get both.

 

[Evan]

Normal saw cover.
From what i just test fit i would not replace with the funky shaped 034 cover


Everything inside fits the same

Left is 034 cover.

Ok heres the west coast cover
inside the normal 026-661 cover

 

[BuckthornBonnie]

Some 1125s had plastic clutch covers; they work, but I prefer the mag (metal). You’ll need the plastic guide pieces. Check what kind of guide system yours has- some use two chip guides, some use a metal plate as most other Stihl’s.

I own 7 of this series and have built most of ‘em up. I’ve been into 3-4 others and have a general idea of weaknesses. Still, this series has more strengths and are fun to run and work on.

 

[dmb2613]

the tang on the worm drive is broken and will need to be replaced

 

[Evan]

Bar that was on mine had the rivets to. Ive never had one before.

This is bar and chain that was on the 034 i put it on 029 to sell. I think its a 20"
If you really want a 034 cover ill send you the one pictured though it does have a crack down center horizontally

 

[Sepia]

I can add a couple suggestions to the thread. As well as making sure the bearings are tight, ensure they are smooth and quiet as well. Easiest to check with the coil removed and obviously cylinder removed. Also, if the saw is spewing oil but the lines seem to be intact, check the flatness of the bar mounting pad on the crankcase. I had one once with a ding/burr that wouldn't let the guide bar seal to the pad and allowed oil to go everywhere except where it as supposed to.

 

[float89]

Thanks everyone!

Work on the saw a little this weekend. Tore it down as far as I need to I believe. Buckthorn, yeah it seems as though maybe this thing is a peice job. who knows. all I know is everything that needs to be on the saw is and I can work with it!

- Worm gear and tang for the oiler are on order.
- Thanks for the offer on the cover Evan! Wont be needed though. I pulled the trigger on one from ebay. Its pretty wore but no crack and its mag.
- plactic guides are on order also
- All AV mounts appear in good shape. No rips or cracks but they do seem really soft. not sure if that is intended or a sign toward end of life?

CJ - Bearings are nice and tight from what I can tell. No movement at all but what is the trigger for noise. I mean I know what a bad bearing feels/sounds like and I dont believe they sound bad. Maybe I am being paranoid but there is a little "swirling" noise when I sping the crank. I really do not want to split the case and do bearings...... :/


Any advise on removing the old base gasket? I've seen some really bad gaskets that stick but this is a whole new level. Expecially because I dont want any to fall into the case...

 

[BuckthornBonnie]

Base gasket- combination of cleaner and scraper. Careful on the case mating surface, it’s softer than ya think.

There were two types of AVs.. “soft” and “hard.” Perhaps you have the soft ones... which is fine. There are part # indicators on the AVs which you can reference to the ipl if ya want. Doesn’t really matter, though.

 

[float89]

Ok yeah, sounds like a few nights of "picking" away at that gasket.

Good to know on the AVs. Info like that is priceless!

 

[pioneerguy600]

Ok yeah, sounds like a few nights of "picking" away at that gasket.

Good to know on the AVs. Info like that is priceless!

You can pack a good deal of shop towel/paper towel into the crankcase all around the connecting rod with the crank bottomed out, pack it in tight and keep debris from the gasket out. Paint stripper applied with a Q Tip to just the gasket will help remove them, I use a product called Tal Strip, just have a gallon jug on hand, curls stuck on gaskets right up off the mag or aluminum surfaces without scratching, use a hard plastic scraper. Make many of mine from discarded snow and ice windshield scrapers.

 

[Mad Professor]

Check your clutch bearing size the smaller ones are more failure prone and stihl sells an upgrade as a kit.

Not sure why your oil output hose off the pump would be pliable unless it's not OEM? The OEM hose is a PITA to install and stiff as a sailor on shore leave.

3/8 20" is the sweet spot for 034/036 bar/chain. I like 33RS stihl

 

[float89]

OK. Update! Been a few weeks I know but I dont want to be that guy who asks all the questions and then is never heard from agian...


Got her all back together with basically a bunch of new parts mentioned, a few extra ones and shoot... She runs!!

Tuned it up and idles nice, revs quick, and at least on the bench holds trottle nice.

The focus now shifts to the bar and chain. I will probably clean this one up and run it. the chain seems fine at least as far as teeth size goes. The bar's sprocket is a worry. Not a lot of teeth left. I will probably buy a new bar and chain and have it ready for when things go south as a back up.

Professor suggested the 3/8 20" which is on it now (dont know if its a 33RS chain though). I'm open and asking for suggestions on a bar and chain. Never had to replace a bar as this is my first "real" saw.

Thanks everyone! Felt awesome hearing this this rev up.

Tom

 

[BuckthornBonnie]

3/8 18-20” is good, man. Go with the Prof’s suggestion.

 

[float89]

Sorry. I should have stated that better. I want to stay with the 3/8 20" but dont know what kind of bar to accually get. are some bars better than others? or any to just stay away from?