Stihl 034 Super AV EQ

I use two stroke oil for assembly.

 

Yep, no prob. There are many ways to do it. I avoid the ways that put too much stress on the cases, bearings, or crank.

 

1. So that's why you need the oil pump in place to make sure the PTO bearing doesn't go too far towards the outside of the case, correct?

2. I shouldn't let it cool back down to room temp then if I'm going to pull the cases together, right?

Makes sense.

 

1. Yep. It’s critical for Stihl saws since the oil pump has a recess for the slightly protruding bearing.
2. I let it cool if I am pulling the crank through. If you don’t, you risk shifting the bearing slightly. I suppose you could do it “warm” but the expansion of magnesium may cause a problem with the bearing position.

 

If you’re not pulling (with a crank puller set or the clutch spider), you can get the fw side case started when it’s hot. That has a positive stop in the casting and is less likely to shift.

 

I've never personally messed with magnesium too much, but at what point does heating it become a fire hazard?
For those not aware, mag will burn like nothing you've ever seen...and hard to put out!
I do know it's the shavings or dust particles off it (sanding /grinding) that are more likely to light up, given a chance...

 

From father google:
What temp does magnesium ignite?

Magnesium is also flammable, burning at a temperature of approximately 2500 K (2200 °C, 4000 °F). The autoignition temperature of magnesium is approximately 744 K (473 °C, 883 °F).

 

I think we're safe with the ol' propane torch. Thanks for looking that up moresnow. That's why these cases don't disintegrate when doofuses like the previous owner run the saw into oblivion with no bar oil.

 

Yep. It has to get really hot to ignite. I’m dropping some bearings into a 55 tonight.
Also knocked a couple out of an 034 case.

 

Three sister 1125 with aftermarket plastics. OEM where it counts. All have Meteors. Built over the last year or so.

 

I would imagine that the piston would be one of those places where it counts....but it seems that Meteor has a good reputation for being a decent AM alternative at half the cost (at least piston wise).

On both of my 2006 Mini Cooper S vehicles I use aftermarket if there is an aftermarket option and only use OEM if I have to. Most of the time they are literally just rebranded from OE suppliers.

Looks like you are having some fun times there! I whipped the hydro out of the garage and finished off the white birch and some pine, cherry, and a rogue limb of black locust. Tomorrow I will finish off the sugar maple and then I can get to making thin wedges out of the spruce for kindling purposes. Going to wait until I get the HF tool on Sunday to see how it does in popping out the bearing.

The bearing in your last pic - was there supposed to be a plastic cage holding the bearings in place? Did some bearings fall out?

 

Yep, plastic cage. I’m not sure if any fell out but they definitely can as you found out.
AM for saws has some major quality issues. Nearly all rubber parts are no good. Meteor pistons are very good. I’ve used many and some have a lot of hours at this point.

 

I ordered 3 OEM Stihl annular buffers: (1) 1125-791-9904 that was ripped, (2) 1125-791-9910, and (1) 1125-791-2805.

The (2) 9910 buffers on the 034 seemed ok, the 9904 was ripped, but I figured I'd replace 'em all.

 

I just rebuilt a 362 for a friend of my neighbor. Not exactly the same issues you've run into but a very similar path as it needed a full rebuild and new piston, rings, bearings, seals and some TLC. huskihl and others had given me advice during the process and I learned a lot and would never have been able to get through it all without the generous knowledge sharing and the positive support and encouragement along the way. I too had thought the cylinder was toast, but Huskihl encouraged me to clean it up and re-use it. It runs now and I've put a couple tanks of mix through it on light duty and not pegging the throttle more than a few seconds at a time in wood. I wanted to break it in like I did when I bought mine new, that seemed to work for me because it seems to run pretty good for being mostly stock. Fixing this saw for him was trial run for me when I tear mine down to attempt to add a little more "go fast" to it.

I ended up having to make many of the specialty tools that I needed along the way for cracking the case open, pushing out the crank, and pushing / pulling bearings out and back in. I did buy a crank pulling tool since I don't have any way to put left hand threads in that tool. That saw was a strato design so it was fun reading up on that and figuring out how they work. One of the most difficult parts for me was getting the PTO side bearing back in. I heated the case in the oven with the oil pump in place and froze the bearing in oil and tried to get it in that way 6 or 7 times and was never able to get it straight... I was getting frustrated. The other side of the bearing had a larger radius on it so I took the pump off and warmed the case a little and pulled the bearing in with a steel plate, a half inch bolt and a few washers that got all the pressure on the outer race of the bearing and it when right home with that set up. I also ended up with a pressure leak on the PTO side seal when I set it in flush with the bearing flange. It needed to be pressed in just a touch further to get the seal up past the step on the crankshaft. It was pretty smooth sailing other than those two items. The vacumn / pressure testing was the way to go because if I had completely assembled the saw and tried to troubleshoot it, I would have gotten very frustrated. Using a mighty vac set up, I could hear the leak and went right to it and was able to visually notice the problem and how to fix it.

Just wanted to give you a word of encouragement on your journey in getting your saw back to "runner" status. Good luck and it's great you have the confidence to go through the learning experience and follow it through.

 

Thank you so much for the words of encouragement. And thank you to everyone who has chimed in on this thread as every experience shared has been helpful. Big shout out to huskihl and BuckthornBonnie who have really gone beyond the call of duty to be as helpful as possible. I have learned a lot thus far and am looking forward to putting it back together.

 

Aftermarket AV mounts are junk. They will not last long during normal use. The 1122 mounts are especially bad and will tear.

 

No worries. Everybody’s gotta start somewhere.

 

Well I got the HF bearing and hammer slide tool yesterday and it took me about 10 minutes to get the old bearings out. The PTO side seemed to be a little harder to get out. Took maybe 3 times as many strokes and I had to heat it up a little longer than the flywheel side. But out they both came and the tool worked exactly as I imagined it would.

Woo hoo!

Before:



Here's the 2nd smallest collet inserted into the flywheel side. I removed those two rubber grommets/stubs as they started smoking when I applied heat to the case. Yikes. Glad I caught that in time.



Flywheel bearing out.



Used the largest one on the PTO side since the inner race of the bearing was not there any more.



That small ring is what I believe is the old flywheel side seal that must have disintegrated when I took the crankshaft out.



For $49.99 I think that tool was certainly worth it.

Back to the regular price of $72.99 atm.

Slide Hammer and Bearing Puller Set, 5 Pc.

 

Here's a short video to show the old flywheel bearing and what it sounds like vs the new one. Yikes!

 

Ok now I'm ready to start putting things back together. This is one nice toy....I mean tool.

Using 50/50 75w-90 gear oil and 5w-30 motor oil. I don't have any ATF on hand or else I would have tried that. What do you guys use in your oil cans?