stihl 034av problems

[psu927]

I have two 026s and they treat me great. Just bought an 034 av really cheap. Brought it home and compared compression to my 026 and the 34 has way less resistance when pulling the string. I guess the first thing I should do is get a gauge. Any particular way to check compression/leakdown? If I do need a piston and rings, do I need the whole head in most cases and last, are the 034 av, 034 super, and 036 heads all interchangeable? I know the pistons are different (I think 2mm bore size difference). Or can I just get an 034 super piston and rings and bore my cylinder out for the larger size? Thanks! BTW I'm good with cars but saws I usually don't have to work on because I don't have trouble with them. And where can I get a good service manual? Thanks fellas.

 

[AKDriveSprocket]

Compression and Squish go hand and foot. Sounds like you my just need new rings. Search button will help you out on all three.

 

[psu927]

Wasn't sure what squish was so I just did a search and looks like there is a lot of reading to do. Whatever I need to do, if I can more power while I'm doing it- GREAT! Thanks ahead of time.

 

[lone wolf]

pull the muffler off while you are waiting for a gauge and look for score marks on the piston.

 

[Mad Professor]

pull the muffler off while you are waiting for a gauge and look for score marks on the piston.

+1 what he said.

The 034S or 036 topends will fit, might need to tweak the muffler a bit.

You can't bore out plated cylinders.

 

[spudulike]

Whip the jug off and inspect the piston, rings and clinder plating, if the cylinder is clean with no wear through on the plating or scoring then you won't need a new one.
Check the piston skirts, any bad signs of wear and scoring then replace, if the rings are worn (check the thickness of the ring ends and compare the thickness to the middle of the ring) then lightly hone the cylinder with 300 grit wet and dry then fit new rings if needed.

A new piston and rings generally gets 150psi+ back

Spud

 

[psu927]

I'll tear into it this weekend and see what I find. If I can get an 036 head (or 34 super) for a decent price would it be worth just doing the whole swap? And where is the best place to get parts? I hope you don't say a dealer.

 

[Mad Professor]

I'll tear into it this weekend and see what I find. If I can get an 036 head (or 34 super) for a decent price would it be worth just doing the whole swap? And where is the best place to get parts? I hope you don't say a dealer.

OEM>Tecomec> all others

 

[psu927]

Ok got some time today and pulled the muffler and all I can say is wow. I'm not sure which but this thing was ran either without and air filter for a long time or on straight gas. The piston is all scarred up and the ring is almost non existant. Safe to say I at least need a piston and probably a head. So I want to go with a 34s or 36, best place to buy? I'm sure I'll have more ???, any advice appreciated.

 

[oscar4883]

You may be able to find a used OEM cylinder on ebay IF you need one. The old one most likely will clean up well. If it is salvagable the Meteor pistons are top notch. Well worth the extra 10 bucks over a cheap import. I have put two NWP top ends on saws recently. One on a 460 and the other on an 034. I have no experience with older aftermarket top ends but the newer NWP top ends are very nice for the price. Just check out site sponsor Baileys.

 

[psu927]

http://www.baileysonline.com/itemdetail.asp?item=CK+036&catID=10162\

So something like this would be decent? And an 034s or 036 will fit my saw with very little modification correct? Crankcase and connecting rod all bolt up?

 

[Stihlofadeal64]

I'll tear into it this weekend and see what I find. If I can get an 036 head (or 34 super) for a decent price would it be worth just doing the whole swap? And where is the best place to get parts? I hope you don't say a dealer.

If it's not scored you won't need to replace the OEM cylinder. It will usually be far better than the aftermarket stuff anyhow. If you're going to tear it down Meteor makes a high quality aftermarket piston and rings. If they make it in the 034 I'd definitely go for it. I just bought one for another saw I own and it brought it alive again. Great compression great power.

Test the compression with a compression tester/guage. If you're in the 150 range I wouldn't do a thing. Tune it and run it till it drops.

 

[oscar4883]

Northwoods Saw has an Episan piston for a regular 034. Assuming your cylinder is ok.

 

[spudulike]

Check the cylinder for aluminium transfer around the exhasut port, if there is any, eat it away with Hydrochloric acid (muriatic acid) - I use an acidic concrete/path cleaner. You can tell when it is all gone as it stops fizzing a white deposit - always wear safety specs.

Lightly hone the bore in a circular (not up and down) motion with very fine wet and dry or finishing paper, you are aiming to lightly rub any deposit off the cylinder wall rather than hone in the true sense - the bores are Nikasil or chrome plate - the paper will have little effect on them an this is what you want!

Nerw piston and you should be up to 150psi - take note as to if your piston/cylinder is A, B or C type and order the correct size.

Spud

 

[psu927]

How do I check if it's a, b, or c type? I know the compression can't be near 150, and the piston looks (through the exhaust port) horrible.

 

[Mad Professor]

How do I check if it's a, b, or c type? I know the compression can't be near 150, and the piston looks (through the exhaust port) horrible.

It is stamped on top of the jug and piston

If you don't go with OEM cyl assy this is what you want:

http://domino2.reggionet.it/Databas...20F9A6BD464A0CCDC1256E71003910FE?OpenDocument

Tiliston/Total dealers are USA distributor

 

[psu927]

ok guys, got a chance today to tear the saw apart and the piston is indeed scrored badly 180 on the exhaust side, with most of the scoring being right at the exhaust port. With just my finger I can feel some scoring (or residue?) on the cylinder wall as well. Not as bad. What causes this? (straight gas? no filter?) Also, what can I use to hone the cylinder to get it smooth again? And how much play should the rod have at the crankshaft, sliding side to side as well as rocking side to side. Thanks.

Oh and is it worth doing any porting to the ports while I have the saw apart? If so, any technique? Thanks

 

[danw]

I may do this on my 034AV as well, since I will be swapping out the lower end. Contmeplating getting OEM 034 rings or the whole 036 conversion from Bailey's. Post pics when you do it!

So who makes the Bailey's kit?

 

[spudulike]

Right - please dont hone in the normal sense of the word - take some Hydrochloric acid - commonly called Muriatic acid (found in concrete path cleaner) and apply to the transferred aluminium on the cylinder wall, it will fizz and go white, clean with a wet cloth and add some more - when it stops fizzing, all the transfer will have been removed.
Please weare safety glasses whilst doing this and wash in water once finished to get rid of the acid.

Use some fine grade wet and dry paper to hone the cylinder, you should rub the bore in a circular motion and not up and down, the paper should be circa 400 grit. Once you have done this, as long as the cylinder plating is in good condition and is not scored - a new piston and ring can be fitted and you should end up with 150psi+ compression

Spud

 

[psu927]

Ok, doesn't sound too complicated. Just a dumb question, what is circa sandpaper? And I'm guessing I can get the acid at a local home center? I have been looking around, and on baileys, the piston and cylinder kit is 100 bucks, same on e-bay, found some for same price, but then some other ones for 2 1/2 times that price. And at baileys the OEM pistion only is 30 bucks more than the aftermarket piston and cylinder kit. Does anyone here have experience with the cheaper ones? I see a lot of peope recommend baileys and I really don't have experience with them to know.