034 Muffler question

[v8titan]

I purchased my 034av saw back in March of 93'. First I would like to say that this saw has served me well over the years and that I'm pleased with it's quality. I primarily use the saw to cut firewood and I would say I cut about 4 cords a year. I know from searching the forum that there are several threads on upgrading the 034 to an 036 by changing out the cylinder and piston. Some of the postings indicated that there are a few different mufflers that were used on the 034. I attached a photo of my muffler and was wondering if anyone out there can comment on the ease of upgrade with this style of muffler? In addition, would I gain any power by just doing a muffler mod? I believe this is a pre EPA saw and I've seen some posts that claim the benefit would be marginal. Any comments?

Tom

 

[davefr]

I just converted my 034 to an 036.

My muffler looked like yours and no modifications were needed to attach it to the new 036 jug and original crankcase. I think the way you can tell for sure is to remove it. If your muffler is attached with 2 steel gaskets and a 1/4" spacer then it should fit fine. You might need the cooling plate shield. (my 034 didn't have one).

I'm happy with the performance gain.

I opened up the muffler but the stock one didn't look that bad. (no baffles or obvious restrictions). Pull out the screen and hog out the exit hole to about 3/4". (it's too easy not to do.)

I really like the 034 even though it's kind of an orphan in Stihl's lineup. No EPA crap, fully adjustable carb, easy to work on, lightweight and powerful.

The total cost of the upgrade was about $130. (it'll net out less once I sell my original jug and piston on Ebay).

 

[v8titan]

I just converted my 034 to an 036.

My muffler looked like yours and no modifications were needed to attach it to the new 036 jug and original crankcase. I think the way you can tell for sure is to remove it. If your muffler is attached with 2 steel gaskets and a 1/4" spacer then it should fit fine. You might need the cooling plate shield. (my 034 didn't have one).

I'm happy with the performance gain.

I opened up the muffler but the stock one didn't look that bad. (no baffles or obvious restrictions). Pull out the screen and hog out the exit hole to about 3/4". (it's too easy not to do.)

I really like the 034 even though it's kind of an orphan in Stihl's lineup. No EPA crap, fully adjustable carb, easy to work on, lightweight and powerful.

The total cost of the upgrade was about $130. (it'll net out less once I sell my original jug and piston on Ebay).

Thanks for the info Dave. Where do you buy your jug and piston?

Tom

 

[davefr]

Ebay. There's aftermarket, used, and new OEM most of the time. I chose new OEM.

 

[Lakeside53]

If you buy the 036 cylinder/piston from ls_quindos, these are genuine Stihl... No idea where he gets them to resell at $75/set..

 

[v8titan]

If you buy the 036 cylinder/piston from ls_quindos, these are genuine Stihl... No idea where he gets them to resell at $75/set..

I don't see that ls_quindos has any genuine OEM Stihl 036 cylinder/piston sets up there at the moment. He has an aftermarket set for $49 + $34 shipping and handling. I sent him a message to see if he will be getting more in.

 

[davefr]

If you buy an 036 cylinder kit beware of the Ebay seller named "cheapstihlparts". That's where I bought my cylinder kit because it was genuine Stihl including piston pin and both clips.

I promptly rec'd all of the above except for the piston pin and one clip. He didn't respond to any of my emails so I had to file a Paypal dispute for the cost of the missing pin and clip. I won the dispute.

 

[Tom_Blough]

*

 

[davefr]

Is the 036 jug and piston on the 034 just a bolt-on affair? Sound's like v8titan and I bought our saws a few weeks apart. Just put on a 25" bar and would like a little more power (what I'd really like is a 460 Mag, but that aint gonna happen according to the wife).

BTW, mine's just a plain 034, it's not the AV.

No, it's a tad more then "bolt on".

1. Most of the 036 jugs on Ebay have fittings for decompression vales. You'll need to get the valve or a plug.
2. The shroud will need to be modified to fit the bigger cylinder. There's a fin on the underside that can be hogged out with a die grinder. Or you could get an 036 shroud but even used ones seem to go for $25+ on Ebay. You will however need an 036 shroud if you decide to use a decompression valve. IMHO the 036 doesn't need a valve. It's easy to start.
3. The muffler may or may not fit. Mine fit the new jug perfect. (it had the spacer which you no longer use for an 036.)
4. Stihl 036's have a cooling plate between the muffler and cylinder. My 034 didn't. You'll need to get that part from Stihl.
5. While the jug is off, I'd recommend you inspect/replace the intake boot and definately replace the pulse line. (the pulse line is only a couple bucks and reported to be an 034's achilles heel. The new pulse line seemed thicker.)
6. Fortunately stock 034 carburation works fine with an 036 jug even though the carb. specs are slightly different. The main difference is the valve jet but that same Zama valve jet that's on the 034 is also on the 036QS model. I barely had to adjust my 034 carb. to work with the 036 jug.


With muffler mods and an 036 jug I think you can get the 034 to about 5 HP. A 25" bar is pretty long for a stock 034. The mods will help but you probably need to upgrade to 460 if you're consistently cutting big wood.
Good luck

 

[Lakeside53]

I don't see that ls_quindos has any genuine OEM Stihl 036 cylinder/piston sets up there at the moment. He has an aftermarket set for $49 + $34 shipping and handling. I sent him a message to see if he will be getting more in.

They are not aftermarket... but he won't tell you that... If you press him, he'll just say "aftermarket", but...

 

[Tom_Blough]

*

 

[Lakeside53]

If you buy an 036 cylinder kit beware of the Ebay seller named "cheapstihlparts". That's where I bought my cylinder kit because it was genuine Stihl including piston pin and both clips.

I promptly rec'd all of the above except for the piston pin and one clip. He didn't respond to any of my emails so I had to file a Paypal dispute for the cost of the missing pin and clip. I won the dispute.

I deal with cheapstihlparts all the time any never have any probems... Sometime he gets behind due to volume, but it's unlike him to deliberately not reply to any emails.

 

[Lakeside53]

Dave,

Is the plug for the compression valve a stock Stihl part? Do you use the stock 034 rod? Do you usually replace the rod bearing?

I know it's alot of questions, but thanks for the help!

yes, the decompression valve is about $20. Rod bearing : I usually replace it - about $8-9, but have put in used good rod bearings.

 

[davefr]

Lakeside previously told me that if you reuse the bearing and piston pin, make sure you install them in the same direction they were originally installed. (I think it's OK to reuse these components if they're from a "low mileage" saw.)

However he also told me not to reuse the piston pin clips.

You only need to remove one of the 2 clips. (I removed both of them because I wasn't thinking!)

P.S.

Yes the decompression valve plug is a stock Stihl item. It runs <$5.

Unless you already know about it, this site will be invaluable because it has the Stihl 034 and 036 factory workshop manuals and parts lists:
www.giftsofwood.com

 

[Lakeside53]

yes, the decompression valve is about $20. I susually replace it - about $8-9, but have put in used good rod bearings.

Sorry, didn't read that you were asking about the PLUG.. thanks DAVEFR

 

[Tom_Blough]

*

 

[v8titan]

Thanks for the feedback so far. I did not get my jug and piston on order yet but I did have a chance to remove the muffler and get a look behind it. I have the spacer Dave spoke about and I guess I will need to leave that out when I put on the 036 Jug and bolt the muffler back on. I took some measurements of the current outlet and it is roughly 1.000" x 0.700", which is a 0.7 sq.in area. I measured the muffler output hole and it measured approximately 0.625" which equates to 0.31 sq.in. Now there is a small slot in the muffler just above the hole which, I estimate, adds another 0.1 sq.in of opening. Somewhere I read on another post that you want the O/P hole of the muffler to be somewhere around 0.8 the size of the jug O/P port. So...opening the muffler hole to 0.750" as Dave stated, calculates out to fit that 0.8 criteria

Now for my question. Do I leave the screen out? My fear is that when the saw is not running, something might get in the muffler port and rattle around in there and even worse, get into the cylinder and really F things up. Comments would be appreciated.

 

[Lakeside53]

Thanks for the feedback so far. I did not get my jug and piston on order yet but I did have a chance to remove the muffler and get a look behind it. I have the spacer Dave spoke about and I guess I will need to leave that out when I put on the 036 Jug and bolt the muffler back on. I took some measurements of the current outlet and it is roughly 1.000" x 0.700", which is a 0.7 sq.in area. I measured the muffler output hole and it measured approximately 0.625" which equates to 0.31 sq.in. Now there is a small slot in the muffler just above the hole which, I estimate, adds another 0.1 sq.in of opening. Somewhere I read on another post that you want the O/P hole of the muffler to be somewhere around 0.8 the size of the jug O/P port. So...opening the muffler hole to 0.750" as Dave stated, calculates out to fit that 0.8 criteria

Now for my question. Do I leave the screen out? My fear is that when the saw is not running, something might get in the muffler port and rattle around in there and even worse, get into the cylinder and really F things up. Comments would be appreciated.

Put the screen back in (search prior threads - there is lots of yelling out this..). If you are concerned about the effect of a screen, figure out its blocking ratio, and increase your port size accordingly. Me? I'd do timed cuts with and without the the screen... you may find no real effect.

 

[v8titan]

Put the screen back in (search prior threads - there is lots of yelling out this..). If you are concerned about the effect of a screen, figure out its blocking ratio, and increase your port size accordingly. Me? I'd do timed cuts with and without the the screen... you may find no real effect.

It's back in there.

 

[v8titan]

As I mentioned in a previous post, I open up the muffler output on my 034 from 0.625" to around 0.750". Today I had a chance to go out and give the saw a try. First thing I noticed was that the saw bogged when I throttled, the solution was to open (richen) the low speed adjuster slightly. After I got the saw accelerating nicely, I opened the high speed adjustment just a touch. (I read in previous posts that you need to run a little richer after opening the muffler up). I proceeded to make a few cuts in a large piece of poplar and the saw was really preforming nicely. After the saw was warmed up, I used my hand held tachometer to check the no load RPM's. The saw was running lean so I adjusted the high speed screw to max out at 13,000 as indicated in the saw manual. After doing this I tried to make a few more cuts and the saw did not like the setting and bogged in the cut. That leads me to my question. Can I readjust the carb forgetting about the no load speed and adjust for max performance? If I do this will I be risking running the saw too lean? I would appreciate some feedback here. I did search the forum on carb adjustments and read up a bit but I figured someone might be able to elaborate here.

Tom