Just_Alex

@Wonky the beast lives! Nice. 🤩

Thanks @spudulike I’ll mull those options over, nice thing with your last method is it requires a screwdriver which I already own

Much obliged @spudulike, I’ll try it! On another note, I’ve been musing if I can fashion some kind of pressure/vacuum testing kit or if there’s not much point? Maybe a bit of flat bar as a seal on the exhaust side of the cylinder, and some kind of tyre valve fitted to flat bar mounted to the intake? This way I might be able to attach a tyre pump to pressurise… not sure what to do about a vacuum test, need to find a way to suck out the air…. Anyhow im sure it’s all possible, just not sure it’s worth it or if running the saw will tell me in other ways if there is a seal issue. Eager to hear your thoughts

@spudulike waiting on parts now- might not get everything needed right away as a couple are on back order from Stihl. Hope I can do it justice! Did a bit more cleaning today and wondered if it’s possible to replace the oil hose through the oil cap somehow, have you ever tried that? The manuals seem to think it’s possible but I’m doubtful I could reach in there. Is it just a matter of pulling off the old hose & filter and shove a new one on with long nose pliers? God I hope the crank seals are still good after all of this 😂

Small update. Rebuilt the carb as best I could. Not a super duper high spec carb kit I fear but at least it’s new and it’s had a clean. before after

Thanks everyone, this has been super helpful and I’m glad I asked. L&S will be glad too, since this has resulted in a rather lush order of parts 😊🤩 The only thing I really couldn’t find on their site was a Bing 48A carb repair kit, so sourcing that is the next mission. I’m keen to see how rebuilding the carb goes, those components look finicky and it’s very possible I might mess it up the first time. I’m starting to get a little bit concerned I won’t be able to put it all back together without having a dozen bits left over🙈. Is there a general rule of thumb in terms of the order people put the saw back together? Put piston and cylinder back on case with new gasket, then put carb (once rebuilt) back into the handle part and then marry the handle part back up with the crank body? I want to add a few things which others may think of as “cosmetic” such as new fuel line, fuel filter, air filter, air prefilter (won’t be able to do a new oil line or oil filter because we are keeping the case closed), the carb rebuild of course…. My assumption is it’s pointless to fit a new shiny piston and then mess it up with contaminants from ancient intake components. Is this a good approach? Oh and should I bother with a new exhaust, or try to get it to run first? I’m not sure what to look for in terms of criteria too judge a muffler etc by, I can’t see much rust for example. Any tips on this? Anyway, wishing you all a pleasant evening 🙂

Thanks @openspaceman, yeah that’s the one. I’ll send them a wee message or see what happens when I place an order. Quite keen to get the rubber parts from L&S as they have some of the original Stihl parts (AV stuff for example).

Really useful info @openspaceman, thanks Still trying to settle for a piston kit but the nicer quality ones don’t seem to have the 50mm available, and I look at the £10 ones and think… is this going to be decent enough? is it made of cheese? I’ll keep looking 🙃

Morning all. I have a potentially very naive question for our brain trust: How come most overhaul discussions revolve around replacing the entire piston, rather than just making sure the cylinder is in hood shape and then putting new piston rings on the existing piston? What are the reasons to go with a whole new piston & rings set over just new high quality piston rings? Surely new rings would give the head and existing piston new life? I’M not trying to be a cheapskate or anything, I’m trying to understand the engineering reasoning (also if good replacement 50mm pistons are hard to come by, maybe keeping the OEM piston plus new OEM rings is mechanically a better option?). Many thanks for improving my knowledge, I’m really really grateful EDIT: I think this answered part of my question. The part of the question around what is better- low quality piston & rings versus old OEM piston and new OEM rings I would still love your thoughts on

For those with too much time on their hands (and might be interesting for @Wonky and other future readers of this thread), found this 028 service manual which according to the introduction also largely applies to the 038. Some cool info in there. 🤩 STIHL-028-038-Service-Manual.pdf

<picks up wood chisel again with trembling hand> phew! I used a chisel a tiny bit but said to myself “Alex, don’t be a fool now, best ask what Spud does first!” thanks Spudulike. Will inspect the breather tube. Clear is better, I get why it’s designed this way. Another thing I noticed is that the rubber grommet thing on the oil pump looks pretty perished, so potentially that could be refreshed too. I’ll see if I can obtain original Stihl parts for anything rubber, but yes as you point out sometimes it seems tricky to find bits for these old creatures.

@Stubby Thanks, I try! Although the rat could be winning this one, jury’s still out!😂 Good thing I have a 5L container of WD40, because: more cleaning today. It’s starting to look like saw parts again, and not like a pile of muck. I could not see any perishing or cracks on the boot, my guess is this saw has sat for a decade or two and has not seen much action and the oily gunk has preserved it like the precious fossil it is! 😄 Carb is a BING 48A / 101A and I’ve decided to make a list of potential spares to order first before placing a bunch of orders. As tempting as it is. @spudulike is the breather hose materially different from the 038’s impulse line hose? It looks like a red (maybe was clear once?) hose. Was super clogged with gunk all around so not sure if it needs replacing or if that’s a non-issue. Or maybe I can just use a bit from the meter-length black hose L&S sell…. Here’s another million dollar question: how does one go about shifting the head gasket off the crank case? It’s pretty much baked on there I think. I don’t want to make any marks on the aluminium so for now I’ve just gently shifted one side of it and when I couldn’t move the rest I soaked it in WD40. Will that do to soften the material? Any tricks of the trade? Pictures below. Aside from the head gasket and flushing the whole crank case and the crank bearing with methylated or pure WD40 to flush out any potential gritty bits that may have made their way down there, I feel like it’s at least at a point now where I can start to plan ordering the components and then have a few weeks of sleepless nights worrying about whether or not I’ll remember how to pit this old hornet back together again….

This makes sense thanks @peatff 👍🏻

Thank you Spud, sounds like I’m vaguely ambling in the right direction. Tomorrow I hope to clean and inspect the head a little closer, I’ll see what acids I can get my hands on too. I’ll remove the carb to see what type it is and hopefully unseat the boot. I checked out of curiosity and sadly L&S don’t have 50mm piston kit listed in stock as far as I can see. Where do I go - eBay? Not sure how rife it is with imitations of the replicas (as a novice I don’t want to end up buying a piston that says it’s Meteor but ain’t, if you see what I mean). I’m trying to work out if the 50mm piston from the 044 will fit the 038 av super, but maybe that’s just the Google algorithm confusing me… If anyone has a trusted source of parts and could link me to their website that would make me eternally grateful. I really like the way this site collates the 038 parts but if I can avoid import duties / get better quality parts that would be great 😂 https://shop.saegenspezi.de/Passend-fuer-Stihl-br-038 Thanks all!

Well, perhaps time for an update, as I have spent some quality time with the old hornet today. I’m fairly certain there is no axial or lateral wobble on the crank shaft, can feel nothing move at all. Clutch is still attached though, not sure if that makes a difference. In the end I could not get to the impulse line (clumsy fingers) so I did take the tank off (wanted to clean under there anyway) and as far as I can see there is no visible crank case seal oil leak anywhere, but maybe it’s too early to tell, as there is still plenty of gunk to get rid of. Impulse line removed and inspected. Aside from stiffening over the years there was nothing wrong with it, to my surprise. I have ordered new tubing from LS. I also had a careful look at the crank shaft bearing by rotating it all the way with a pointy thing to make sure the race is not broken (poor @Wonky!). Bearing race looks good. Questions I have: 1. Boot- can I remove that from the cylinder side by tugging/gently prying? Or do I need to work from the carb side and remove the carb first? ( @spudulike if I proceed to the MotoMix side I’ll need to remove the carb anyway…). I’m having a hard time inspecting the boot for cracks in position so would like to replace it I think. 2. The crank case / tank case mounting: are the black rings supposed to be attached to the plastic tank assy or are they broken off “slices” of the rubber AV mounts? 3. Good idea to replace the river AV mount grommety things all over I assume? 4. is there supposed to be any fleece filling inside the air filter? Looks like nylon webbing front and back but is empty inside for me which I found odd, but maybe it’s intended this way. 5. The drive shaft on the sprocket side- I can see some tempering colours on the steel- from dark straw to blue and back to straw. Is this caused by normal operation or is this a symptom of overheating in the past? 6. The oiler set screw at the base of the crank case seems a bit weepy, is that normal? I’ve not tried unscrewing it but maybe there’s an o-ring in there that might want to be replaced? Anyhow, I am rambling. Thank you all for all your input, I’m trying to learn as fast as I can, and am actually enjoying this. If it weren’t for you I’d probably have sold the saw in parts or something, I don’t know. I might still fail here to get it back to life but I’ll have learnt a lot. 😊