034 gets surgery

[ross_scott]

got to give the 034AV that I got last week a run through some good sized logs. after a few minutes I noticed that the idling revs were getting higher which seemed odd to me so I did a quick check of all the moving parts on the carb to make sure no foreign objects were jamming the throttle open a little and there was nothing put the covers on and restarted the saw and it did the same again it got to the stage that you could just about cut with no throttle I got a screw driver out and adjustd the low jet on the carb and it settled so I did a few more cuts and it was back to step one so I took the saw home and did a strip down of the saw the following list is what i removed & checked

Carb boot = fine
impulse line= Replaced the other day
cylinder = Bolts were loose & Bore is severely scored on the exhaust side
Piston = scored on two sides

Also checked for play on the crank bearings there is no play in the crankshaft . I do have a brand new cylinder and piston coming but it is for the 034 super/036 I know that these will fit so I am kinda glad I hit buy it now on the auction to get them as a backup set incase of cylinder and piston failure. also going to get a carb kit for it(tillotson) while I am at it. ironically I had took the saw back the jonsered dealer who sold it to me earlier in the week when it ran like it did(excessively fast idle) when I started it to prune a couple of poplars he said he checked over and it was all good "yeah right"

 

[Lakeside53]

Didn't you say in your prior thread that you replaced the cylinder gasket? Did you torque down the bolts correctly?

You may find problems with the muffler fit on your new cylinder (it will stick out too far) and shoud. There are three different mufflers. Also, get the right carb - the Tillitson isn't set up for the 036 displacement. It will work, but... Get a C3A type from an 036 or 34S

 

[ross_scott]

Hi Lakeside, I did replace the cylinder gasket and I thought I had done the cylinder bolts up tight as they felt tight to my feel with the torx head tool that I was given (the one that is just a piece of thin steel bent over to form a handle not the proper t-bar type) I will be getting the local stihl dealer to torque down the head and tune the carb up will see if the stihl agent has a zama C3A carb and see if he will do a swap plus some cash for it if not the tillotson HK43B will have to do for the moment(confusing that collectors corner lists the HK43B aswell as the C3A for the 034S). The part number on the side of the muffler says 1125400 H does that sound right to you?

 

[Lakeside53]

I'd strongly suggest you get an inch/lb or NM Torque wrench, if for no other reason to "get a feel" for what torque you need when not using the wrench. It's very unusual for cylinder bolts to get loose a few days after you install them unless you didn't torque them down correctly. The service manual give sou the torque settings for al the screws on the saw. I doubt you can get enough torque with the bent wire style "wrench".

The muffler problem is that the cylinders vary from the original design, and therefore so do the mufflers. You'll have to wait and see if your's will fit. It will possibly be 2mm too far forward, and you could just put in spacer washer(s) on the front mounts, but you'll need to shave the plastic off the top off the shroud, if it fits at all. I upgraded an old 034 just like yours to a 036, and it was a series of headaches. Did work fine though when finished, and is still pounding though wood 2 years of extensive use.

 

[Lakeside53]

..also, if your cylinder wasn't scored before you had this problem, then you should look very carefully at your carb (Just tune it rich to be safe.... no "power tuning until you have a feel for what is going on). Sounds to me that you leaned out and burnt up the piston/cylinder. Even "loose" cylinder bolts probably didn't suck in enough additional air to do this... that would mainly affect idle.

 

[cbfarmall]

The two times I've dealt with loose cylinder bolts, the cylinder got so loose the saw wouldn't even run. Nothing was damaged. So much air gets sucked in, the saw can't possibly run.

Since you checked the boots, I'd take a look at crank seals. And make sure the case halves are tight.

Chris B.

 

[Dadatwins]

Beside torqueing down the head bolts, I use some high heat loctite when putting in the bolts. Just had to put a piston and head on an older 066 that did the same thing as descibed, ran up high with out the throttle and the guy kept on cutting. Head bolts on exhaust side were loose and scored piston and cylinder.

 

[ross_scott]

I never did the carb adjustment it was a dealer (not a stihl agent) that readjusted the carb as I am terrible when it comes to tuning this is why I am getting the stihl dealer to torque the head(just to make sure the bolts are tight) and adjust the carb once I have the cylinder and piston installed

 

[JimL]

My 034 has a 36 cyl on it, i had to make some spacers for the lower muffler bolts and also some surgery on the top cover, other than that it fit like a glove and looks stock.

 

[Lakeside53]

Be careful using high temperature loctite (Like 272) on the cylinder to case bolts. The case temperature is not high (not above 300F), and you'll need to use heat to get them out or risk breaking them off (or the threads). Loctite 241 or 2 (blue) is all you need, but you shouldn't need loctite at all. For the Muffler into the Cylinder use 272; for the muffler to the case (front screws) use 242.

 

[ross_scott]

Got the new cylinder and piston today installed it (did the bolts up as tight as I could get them) took it into the local stihl agent for tune up and torque down of the cylinder and he refused to do anything on the saw unless he dismantled what I did to check and make sure the piston was put on the right way (HMMMMM) I told the guy that the piston was installed exactly same way as the original piston was sitting (top ring indexing nipple facing the rear and the bottom ring indexing nipple facing the clutch side), never heard of a right way and wrong way to put in a piston. I consented to him doing that just so I could get the saw tuned on the tachometer even though it will cost me more on labour. Lakeside the muffler I have on it is exactly how you said the issue may be just going to put some spacers in behind the front muffler bolts also in the process of modding the top cover so the chainbrake is not obstructed by it. cheers for the advice so far cant wait to give it some work to break in the new piston and cylinder. Oh yeah it cost me $29.00 just to get a lousy plug to block off where the decompression button is meant to go (not paying over $50 for a decomp button) the way i see it is if i can start an 044 or a 371Xp without the decompression then i can handle starting the 034S/036 (dunno what to class it as )

 

[Lakeside53]

There is definitely a right and wrong way for the pistons.... wrong way it will last abut 15 seconds at power, break a ring and it will mess up you nice new piston and cylinder! There is an arrow mark on the top of the STIHL piston that points to the exhaust (which you can see on a NEW installation by looking though the exhaust port....), but the easiest way to remember this is that the pins (where the rings lock) have to be on the carb side.


Always ready to help a fellow kiwi...

 

[Lakeside53]

also, put some heat reflective tape (aluminum) on the underside of the shroud above the muffler. The 036 also has a heat deflector between the muffler and the cylinder... (which will move you out another 1mm or so..). Not sure if you absolutely need it, but it's on the 036.

 

[ross_scott]

the pins (where the rings lock) have to be on the carb side.

That is exactly how I put the piston when I installed it the ring locking pins are offset one faces the carb and the other faces the clutch side

 

[ross_scott]

I finally get my saw back tomorrow after waitng for a week for them to look at it

 

[ross_scott]

Sorry to dig this thread up again but I thought i would just say that this thing runs awesomely had it out doing some work with my class mates cutting up trees with approx 18"-24" trunks and it chewed that wood up like it was a starved dog. One of my classmates was impressed with the performance of it that he just had to put his MS440 down to have a cut with my saw his opinion was that it performed just like the 440. I did drill out two of the front baffle holes to 8.5mm (don't know if this has anything to do with why it is performing so good) also I was wondering if you can get dual ported mufflers for the 036 as I do want to buy a new muffler at some stage (the current one is pretty beat up and has had the splits on the front brazed as a short term safety measure). BTW I do have a chainsaw race coming up soon against my tutor and it will be MS440 VS my 036 both saws are using stihl bars MS440 has the 18" rollomatic ES mine has the rollomatic E both are using stihl rapidsuper chains and 7 tooth drive sprockets