Stihl 07 (1961-1965) Rebuild Process.

[Vintage Engine Repairs]

Like my other 4 saws I have rebuilt in my short time here, I want to share the ups and downs on the Stihl 07.

I know that it needs new seals and gaskits at the very least.

I had already done a superficial clean to get access to the intake and exhaust to do a pressure and vacuum
but anyway, here it was before I started with .404 chain on a hard nose bar.




I removed a bunch of parts and proceeded to soak them on evaporust to clean them up.



this is half way through cleaning...




The magnets that are actually separate to the flywheel connect directly on to the crank, it was impossible to remove with hitting the crank, so I rigged up a bearing puller, worked beautifully...





the previous owner swapped the points and condenser with electronic ignition but his wiring was dodgy and poorly connected, so I rewired the whole thing starting at where the points and condenser was and working my way through the rest of the circuit.




I then tested all connections to check for any breaks / resistance and it was good.

I reconnected all the wiring and got it back onto the saw


and cleaned the spark plug spring of the rust present that may affect connection.



then reconnected it to the boot.


I accidentally disassembled the Oiler, which I would have done anyway, but not so soon. It will be tricky to replace but fingers crossed it will go smoothly.

This sets the baseline / starting point. The saw is clean, free of all oil and fuel and is ready for a full strip and rebuild.

I’m trying to get the clutch off, but I can’t even get the spacer off, it must be rusted on really well, trying some evaporust rigged up to the crank shaft and spacer via a plastic bag hoping it will help, other than this I’m out of ideas!

 

[Vintage Engine Repairs]

Here is my evaporust setup to try and dislodge whatever ( rust?) it is that is stopping the ininner sleeve for the clutch bearing from sliding off...

then on to the rebuilding of the Oiler. I don’t think this one can be stripped and cleaned on the inside. When I took it off the first time everything shot everywhere so I had no idea how it went back together. A couple of hours of trial and error and I think I have it...
this should be the order...

Starting from right to left, you need 5 hands and 4 eyes to get the rollers in while you hold back the spring, hold the shaft from rotating and hold the pump cover.... Either that or some determination and extreme patients. If you’re the swearing type, a long list of expletives

And just like that she’s a good-un!

 

[Vintage Engine Repairs]

Right, back on the sleeve and clutch, i have spent more time than I care to admit trying to get the darn thing off.

firstly I held with a pipe wrench and tapped the crank, but the nut wasn’t high enough and now I have the first two threads on a part of the crank slightly bent over. Taking the Nut off destroyed the nut. I’m now trying to source another - m10 x1 LH thread and trying to figure out how best to straighten the threads back up - I’ll probably buy a thread file.


Back to removing that bloody sleeve and clutch.
Then I tried heat and tapping and pipe wrench with the piston locked in place with cord. Nothing....

Then I considered throwing it across the room for the 10th time, but the thing is literally built like a challenger 2 tank...

A few hours of the above ensued over and over..

Then I thought back to how I removed the magnet and cover on the flywheel side. So I proceeded to set it up my bearing puller but just using the bolts and getting purchase on the spacer behind the clutch.

the first 5-6 times it just bent the spacer and the jig would pop off, but I figured persistence was key. On the last attempt I had (the spacer was so deformed by this point) I heard a pop! Then eased it more, a bit more of a pop and some more, then bang, the jig came off... grrrr

Then I realised that if I gently tapped the clutch down I’d be able use the bearing puller as intended...



then I tried to pull the clutch up with the first method and finally it gave way!!
Ah yes, the deformation,... I’ll sort that later!



then I pressed the adapter sleeve out of the clutch on my shop press -


I love using that press!

then I prised the clutch shoes off the spacer....


So in summary, this 07 has been a total and utter pain in the behind so far!

I’ll soak parts in evaporust before going over them (and the crank) with scotchbrit.

I’ll next straighten up the spacer and get back to fixing those two threads with a thread file!

 

[L34]

If you can get a lh thread chase die (split die)I would use that.

 

[Vintage Engine Repairs]

Ok Update

threads have been cleaned with a file and I’m awaiting the replacement LH nut from stihl, should be here in a couple days.

today I worked on the electronics and kill switch.

checked resistance of the switch and wire and got 7.3 ohms of resistance. Pretty bad and not surprising with the rust that’s coating it. I know the switch will work at 7.3 ohms, but I wouldn’t trust it, and will only worsen in time.




So taking the switch off and apart, I then cleaned the housing of rust and unsoldered the wiring and used a wire brush to remove the remaining solder and rust on the connector



A clean connector -
I

Then I checked the connection through the switch alone to make sure I’m not jumping over an issue and I got 0.1 ohms of resistance - perfect...



I then fluxed and re-soldered the wire to the switch



And retested the complete circuit, again back to 0.1ohms of resistance. That’s now a perfectly reliable kill switch.

next was to clean the ground connection as that had corrosion too



After cleaning..



of course, the proof of the pudding (see next post)

 

[Vintage Engine Repairs]

So the test of a good job of the above - First picture there is spark...

And with some help from my girlfriend pressing the kill switch there isn’t any spark..

 

[trains]

At least the nail polish is on the correct nails.

 

[Vintage Engine Repairs]

At least the nail polish is on the correct nails.

Mate that’s my hand you miss read the text, I didn’t punctuate it correctly,

“And with some help from my girlfriend *who is pulling the pull cord* pressing the kill switch *myself* there isn’t any spark”

Hehehe

 

[Vintage Engine Repairs]

I’m starting to fully understand the importance of gentleness in small engine mechanics and trying to correctly apply it. That and also mistakes cost you 4 times, firstly your time, waiting for the part, the cost of the replacement part, then buying the tool to fix the mistake.

I have much to learn, but every setback is a setup for a comeback.

This said, I spent the last 2 hours cleaning the damaged threads on the crank. I tried the thread file with some success, but not enough to get the nut on, then I moved to a selection of hand files to shape the threads with a greater degree of accuracy and control. Then I finished off with the dremel and a sandpaper disk.
Then I screwed the nut on with grease a little way and gently backed it out, cleaned it with parts cleaner, re-greased both sets of threads and repeated this about 20 times until the nut travelled the whole length of the thread and would come on and off by finger pressure

it’s a mistake I don’t want to make again and now I know why it’s so important that crank nut must always be perfectly flush with the crank... I had cleaned everything up by the time I remembered to take a photo, but here is the new nut and fits beautifully.

My next job is to get the springs in the clutch sorted.

 

[HarleyT]

Thread file was the way to go, you would never find a L.H. chaser...

 

[Yukon Stihl]

Thread file was the way to go, you would never find a L.H. chaser...

Hard to do on a small nut but if you cut grooves in a good nut it will act as a thread chaser.

 

[Vintage Engine Repairs]

Hard to do on a small nut but if you cut grooves in a good nut it will act as a thread chaser.

the nut is softer than the hardened crank though so it will just chew it up.

 

[Jkstihl]

Bro build a fan base on YouTube and make bank.

 

[Vintage Engine Repairs]

Bro build a fan base on YouTube and make bank.

That’s a good idea mate! Too much effort though, I use chainsaws to get away from social media haa also I don’t have enough experience or knowledge and there is nothing worse than someone recording videos like that who do things wrong or don’t know what they are doing.

 

[Vintage Engine Repairs]

so here is the threads on the nut, it runs the length of the crank thread under finger pressure, a spot where it takes a touch more effort, but still hand pressure, so all in all, it looks pretty good and not chewed up.


Off to stihl to see if they have a replacement with the clutch springs,

interesting to see what looks like some sort of flaw in the steel of the spring at the area where it’s broken. Also, the clutch shoe has a strange area of edge wear where the spring wasn’t connected meaning it’s been run with a damaged spring for a while. 10x magnification of spring damage.

 

[Yukon Stihl]

the nut is softer than the hardened crank though so it will just chew it up.

Not if you get a tempered one,they come in different tempers.

 

[Vintage Engine Repairs]

Not if you get a tempered one,they come in different tempers.

I fear that will be rarer and more difficult to get than a LH chaser though

 

[Yukon Stihl]

I fear that will be rarer and more difficult to get than a LH chaser though

Probably not if you look in the right places,way cheaper

 

[Vintage Engine Repairs]

Probably not if you look in the right places,way cheaper

Ah okk, good to know, thanks!

 

[HarleyT]

At least the nail polish is on the correct nails.