Stihl 045 AV Rebuild.

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
It's been open. More like a bag o' snakes now. LOL

If it were my saw I'd probably just run it as is for a fun saw/firewood saw. Problem is, it belongs to a fellow who bought it super cheap (non-running) for a small milling setup. He brought it to me to assess and possibly rejuvenate for his purpose. I did, and the rod bearing immediately failed. (there's actually a tech note about the needle cages failing). I felt obligated to make good on his trust in me and scrounged up a new crank to rebuild it again which is where I am now This'll be the third time I've had it apart down to the case and crank..., and hopefully the last. I'm so far under water with this saw it's ridiculous.
Ahh it’s not your saw. Understood! Is the tech note about the small or big end failing?
 
Found a small, defective area on the inner race of the PTO bearing. Maybe some flaking when I pushed out the original crank? Used the heavier compound on both surfaces per the directions this time and slapped things back together. The original applications didn't wander too far inside the case. A little bit was still semi-liquid, but it had set up for the most part. Gave my splitter a run for the money. Will let this application set up for 24-48hrs. and see where it takes me.
Not sure if this might be useful?

There is a listing on ebay for NOS 045 clutch side bearing/seal,

9523 003 0440

for $50, free shipping.
 
Thank you for the heads up. I did actually see that the other day while searching out of curiosity. That would be the one I'd need for the particular (earlier) case and there's another one (0440) also listed for $45. I guess competition is keeping the prices down on those. Hahaha.

This guy must have the last two known 4460's on Earth. At least they're priced like it. LOL But hey, if you have the money...
https://www.ebay.com/itm/NOS-OEM-ST...E-BEARING-PART-9523-003-4460-S3-/114324250681
But as it currently stands, splitting the case and redoing the sleeve compound on both the crank and the inner race as JD suggested created a good seal this time around. Turns out the version of Permatex Green I bought for just this purpose was slightly different than what I thought I was getting. I thought it was also a wicking compound, but just for slightly larger spaces. It's indeed a sleeve retainer meant to be applied pre-assembly for the desired results.

There is still a very, very, very small vacuum leak, but not one worth chasing at this stage of the project. It certainly passes any modern leak specs. Now I just hope it holds up. The retaining compound should easily handle both the heat (300C) and the stress (3000 pounds per square inch). We'll see. Hope to get it fired up tomorrow unless I encounter what I suspect may also be a timing issue with an aftermarket coil I bought for this thing. Good news there is I have a nearly new OEM coil in an 041 to swap over in the absence of a dial gauge and degree wheel to do it the preferred way. Hell, I just line up the marks on the case and the stator plate, tighten the screws, and start pullin' the rope!

Anyway, thanks for lettin' me butt in. Sorry if I'm gettin' the rug a little dirty.
 
Well, I got it back together and it popped after a few pulls then fired right up and ran for a minute..., then died and has been dead since. Would not stay running without feathering the throttle above the idle circuit and it seemed like it was loading up pretty bad. Turned out it was and I flooded it even worse trying to restart it.

Pulled the carb apart and discovered I had the gasket and metering diaphragm backassward. All else looked good and the carb holds 7psi solid. Not sure of the spec, but also not a fan of pumping the snot out of a carb just to test popoff. Anyway, still no joy and there's also a bit too much spitback for my money.

I went ahead with the known good OEM coil to eliminate that variable right out of the gate. Still have great spark with the flywheel key still intact so I'm pretty sure it's not a timing issue from something coming loose (or apart) there. That said, I'm not even getting a pop with fuel straight down the pug hole now.

I'm leaning toward a flywheel side oil seal failure from being too deep in the bore and right up against the inner bearing race due to a less than desired installation method (and result) -- plus being a softer rubberized housing bearing vs. the typical rigid steel housing design. If the seal failed and there's now a massive air leak, that could explain things. I anticipated this possibility at the time and simply chose to take the chance vs, replacing the seal. If I'm lucky, that's what I'll find. LOL

At least I'm getting plenty of practice at remembering the choke rod needs to be attached to the lever in the handle before putting the handle back on.
 
At least I'm getting plenty of practice at remembering the choke rod needs to be attached to the lever in the handle before putting the handle back on.
Yeah, there have been a few times I've gone to hook it up and realized I needed the handle off to do it. One of the biggest pita's on the saw in my mind.
 
Looks like I may have created a 'timing' issue after all. I wrestled like crazy with the wiring grommet because I neglected to install it into the case before mounting the tank as I should have. In my ensuing frustration, I also (obviously) overlooked re-dressing the plug wire down into its routing area after getting the coil screwed onto the lead and mounted to the stator plate. (There is definitely an order of assembly that makes life easier if properly followed!) The resulting high tension short to the flywheel certainly didn't take long to occur and is probably all that was wrong to kill the saw.

0410211626_resized.jpg

My seal concern may be unwarranted, but if it's not up against the bearing it's damn close. It's holding fine after retesting, but I'll change it anyway since I have another one on hand.

0410212005_resized.jpg
And speaking of leak testing, Tom, what did you rely on for a vac spec? It was sort of a new thing back then and being referenced to bar and psi measurements instead if inHg. 7 PSI / 0.5 bar for pressure is pretty standard, but using the same for vacuum via an inverted testing method equates to around 14 inHg which is a bit high even by modern saw standards, though I do generally use 8 ~ 12 as an acceptable range for establishing a stable value over time. That said, I can't get anything over 9 inHg with this saw. It'll hold 7psi pressure indefinitely and will sustain 8~9 inHg vacuum for several minutes before slowly giving it up. Certainly acceptable, but not what I normally shoot for. Just curious about your numbers and how you derived them. With any luck, swapping the above seal may do the trick, though I'm skeptical of the rubberized seal design used in a conventional case bore vs. a clamshell where it's a compression vs. interference fit. They can be pressed in by hand in this application and I was disappointed to receive them instead of traditional steel body seals -- which you appear to have been able to acquire for your f/w side seal? Hard to tell with the Dirko.

So I'm on hold until Monday and a new HT lead. Now where did I put that other seal so I wouldn't forget where Input it....?
 
Hey mate, that seal of yours does look a touch deep, but I do recal there being a bit of space between the race and seal on these saws.

I just follow the manual and did pressure to 7psi and vac to 7psi mate. That’s what it calls for. See page . Put a puddle of very thin oil on the seal (3 in 1) and pull 7psi vacuum and see if it sucks it in.

Pressure specs:
E9953891-14CF-4290-AA52-FC6A7C802BE7.jpeg

Vacuum specs21F44568-DE62-446F-811E-993889B2B643.jpeg
 
Another superb job. Should easily last another 40 ~ 50 years!

As recoils go, these particular ones are very easy to refurbish (including the spring) as you've so capably demonstrated. Otherwise, and aside from being improperly lubricated all too often, they're one of the most neglected assemblies on a saw until either the rope or the spring break. Some can be quite tricky and even rather unforgiving on the 'ease of maintenance' scale. I bought one of these quite a few years ago just before they quit making them. A bit expensive at the time at around $50, but will handle any recoil spring rewind and installation situation with the exception of extremely deep housings where the tool simply can't reach. It paid for itself with the first use.



Regarding the pressure and vac specs, thanks for the response. I'm going from the same specs from the same manual with the same antiquated methodology and terminology for describing and conducting a vacuum measurement. The curiosity in my previous post was about your interpretation/conversion of the published vac spec of 7psi/0.5 bar to today's current measurement standard for vacuum which is inches of mercury -- or inHg as measured using a MityVac and as displayed on the left side of the gauge. Your pic is showing a vac of 7inHg which is only about 3.5psi using a psi method or pump with only a psi gauge for indicating both pressure and vac measurements. I was just curious, as in my particular case, if that's all you could draw since 7psi would actually give a 14+ reading on the inHg scale. The closest I can get with the case I'm working on (if converting to psi) is only slightly over 4 which is on the lower edge of what I typically accept.

It's all semantics based on the type of measuring device and type of gauge used, but understanding the differences to ensure actual conformity to the particular specs is important to understand and apply.

Bottom line -- neither one of us is even close to 7psi with our case vacuum integrity unless you can actually draw and hold 14inHg on yours. I sure as hell can't with the one I'm working on. I'm hoping the new seal will remedy that.
 
Another superb job. Should easily last another 40 ~ 50 years!

As recoils go, these particular ones are very easy to refurbish (including the spring) as you've so capably demonstrated. Otherwise, and aside from being improperly lubricated all too often, they're one of the most neglected assemblies on a saw until either the rope or the spring break. Some can be quite tricky and even rather unforgiving on the 'ease of maintenance' scale. I bought one of these quite a few years ago just before they quit making them. A bit expensive at the time at around $50, but will handle any recoil spring rewind and installation situation with the exception of extremely deep housings where the tool simply can't reach. It paid for itself with the first use.



Regarding the pressure and vac specs, thanks for the response. I'm going from the same specs from the same manual with the same antiquated methodology and terminology for describing and conducting a vacuum measurement. The curiosity in my previous post was about your interpretation/conversion of the published vac spec of 7psi/0.5 bar to today's current measurement standard for vacuum which is inches of mercury -- or inHg as measured using a MityVac and as displayed on the left side of the gauge. Your pic is showing a vac of 7inHg which is only about 3.5psi using a psi method or pump with only a psi gauge for indicating both pressure and vac measurements. I was just curious, as in my particular case, if that's all you could draw since 7psi would actually give a 14+ reading on the inHg scale. The closest I can get with the case I'm working on (if converting to psi) is only slightly over 4 which is on the lower edge of what I typically accept.

It's all semantics based on the type of measuring device and type of gauge used, but understanding the differences to ensure actual conformity to the particular specs is important to understand and apply.

Bottom line -- neither one of us is even close to 7psi with our case vacuum integrity unless you can actually draw and hold 14inHg on yours. I sure as hell can't with the one I'm working on. I'm hoping the new seal will remedy that.

Thanks for the kind words mate :) damn I’m still so confused by the different types of gauges and measuring devices and nomenclature. I’ll have to re-read your post a few times :)

That’s a cool little device!! I must admit that I don’t have an issue with the springs (those damn piston c-clips though, I quickly invested in OEM tools for 2 different sizes of clips!!), I just position the outermost end in place and then work my way around and around until I get to the other end and voila.

Hey, do you happen to know if the nozzel check valve in the HS 118A carb is the same in the HS118B carb?

Edit To Update.

i re read your post again, how interesting!
Why doesn’t the mityvac just read in PSI both ways? Crazy.
So when you Vac test saws normally what do you go to? And when you pressure what do you go to?

So technically I should always be doing about 14 inhg on the mityvac for Vac and just the normal 7 psi for pressure?
 
Why doesn’t the mityvac just read in PSI both ways?
A MityVac simply offers the functionality and appropriate gauge readings to effectively do both conveniently. A measure of vacuum is actually a pressure differential, not a measure of pressure itself. A MityVac simply performs and represents both measurements in their appropriate form. Yeah. Crazy. LOL

I usually shoot for a solid 8~12 inHg for vac and 5~8 psi for pressure as a rule of thumb. A typical seal is only going to be rated for 10~12psi anyway (even though they'll usually hold well past that). There are several schools of thought about how long each should hold over a given period of time. I say the longer the better and shoot for no leak in either direction..., which is usually attainable with enough effort and attention to the details.

I see the nozzle question has been answered. (Hi, Sebastian.) The Tillotson nozzle number is 363-518 and does not include the check valve feature..., at least not in the 'B' application on an 056AV. Perhaps there are check valves in the other designations? I don't know and don't have specific application details for the other variants, though I don't recall one being present in the 'A' version I'm working on.
 
Hmm when you say doesn’t include the check valve feature I’m confused? The PN is for the check valve? I’ll call the dealer in the morning, no doubt it’s NLA though through Stihl.

tried polishing the ball and seat still leaked though 7A8137E7-D7AD-439C-9511-9E568F97827B.jpeg527D066A-E5E5-4A67-AB15-87605C27F0AF.jpegC1CC3D03-8C5F-458A-A4ED-FBCE9DFB95A6.jpeg
 
Hmm when you say doesn’t include the check valve feature I’m confused?
The HS series came in many flavors for different applications and specifications for many power equipment companies. You'll find the 118B on page 8 and will get a feel for navigating the document fairly quickly. You may have better luck directly sourcing Tillotson parts than relying on your Stihl dealer unless they've cultivated some long standing and reliable sources for such parts. Not likely to be many old Tillotson parts on Stihl shelves these days..., at least not on purpose.

On the other hand, Googling Tillotson 363-518 gets you back in business on several levels for $10~$15, including what is obviously a nozzle and check valve assembly with ball and cage -- not individually indicated on the parts list for the 118B -- which had me a little confused given the absence of a welch plug, screen and clip which in many cases provide access and protection for a check valve. My bad, there. Sorry for not being more thorough on the matter before making such a general statement..
 

Attachments

  • HSPartsList.pdf
    751 KB · Views: 0
Back
Top