I would try to fix the helicoil if possible, OEM cylinders are generally much better (and longer lasting) than most AM.
New to me Stihl 038AV Super, photos and a few questions
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The way I baby my saws anymore they could probably make the cylinders out of plastic and they'd last me a long time..
I'd try gentaly tapping/ screwing it in with a small hammer and blade screw driver. Just hold the saw by the bar in a vice and take your time. May just spring back, if it doesn't try spraying the thread with wd40 for lubrication. Got nothing to loose and won't cost you anything. You may also be able to work it in with the spark plug, chances are that's how it came out in the first place.
When I had trouble with my VW sparkplug hole I went to NAPA and got an insert kit rather than Helicoil. You drill the spark plug threads out and tap and screw the new insert into the hole. Everything is included in the kit. It worked as long as I owned the car. I don't know if that would work for a chainsaw or not.
thanks for the thoughts guys. It does seem worth trying to save things before ditching the cylinder. I'll get a photo later, if I can get decent light on it. I'm not sure if it was correctly installed and worked itself out, or if it was never in right, My dad couldn't resist diving in before thinking and gave it a good poke about with a screwdriver, it didn't seem too loose hence why he felt if the half turn out the top could be removed then the rest would stay put and be fine. I am more inclined to try something like this today, and move on to a new insert, helicoil or otherwise, if things don't work. I'm wondering if an extra squishy washer on the plug would allow it to seal despite the bit of helicoil that is laying across the sealing surface, something like a copper crush washer, maybe even a smear of plastic gasket compound. It's only pennies to buy a washer and if then pressure test the saw to see how it is holding I'll feel less worried. I read the best way to make up a pressure testing kit is from a shygomanometer (blood pressure testing thingy) as they have all the hose, a bulb/pump and a gauge, and cost under a tenner on ebay.
If it does need a new insert and needs retapping for it, I'm assuming the cylinder needs to come off the saw, as the risk of swarf inside the chamber just isn't worth while trying to fir it with the cylinder in place
If it does need a new insert and needs retapping for it, I'm assuming the cylinder needs to come off the saw, as the risk of swarf inside the chamber just isn't worth while trying to fir it with the cylinder in place
Where I used to work we would drill holes while holding a vacuum cleaner up next to it, seemed to work okay. Takes a powerful vacuum cleaner though..
Have good look at the h-coil. threads ca be hanging inside too. If that breaks loose could trash P/C. I'd first try grinding or cutting off the protruding heli.
Have you looked inside thru muffler and is P/C in good shape?
A good OEM cylinder is better than 99% of the Chi-Com manure being sold. Tecomec Italy used to make OEM quality P/C assys, they are now CHi-Com too. Not sure if Meteor has kit? If you replace go with a 52mm it's only slight modifications (do a search here). Try to find a good OEM used, Italian Tecomec, or maybe a MS381.
Have you looked inside thru muffler and is P/C in good shape?
A good OEM cylinder is better than 99% of the Chi-Com manure being sold. Tecomec Italy used to make OEM quality P/C assys, they are now CHi-Com too. Not sure if Meteor has kit? If you replace go with a 52mm it's only slight modifications (do a search here). Try to find a good OEM used, Italian Tecomec, or maybe a MS381.
good advice thanks, I'll have a really close look at the helicoil and check but I don't think it extended inside.
haven't had the muffler off no, is it easy? just a few screws I assume? I'll do it and check inside. It sounds like it worth trying to save the oem cylinder if possible. I'm thinking if i can borrow a dremmel it may reach down to grind off the protruding helicoil. If I can get the saw hung above me as i work so any swarf falls down and away, maybe put the shop vac on blow and tape to the exhaust port too, that would have a fair gale blowing out the plug port as I worked to keep swarf out too. and depending on what is left, a copper crush washer on the plug may help with sealing.
haven't had the muffler off no, is it easy? just a few screws I assume? I'll do it and check inside. It sounds like it worth trying to save the oem cylinder if possible. I'm thinking if i can borrow a dremmel it may reach down to grind off the protruding helicoil. If I can get the saw hung above me as i work so any swarf falls down and away, maybe put the shop vac on blow and tape to the exhaust port too, that would have a fair gale blowing out the plug port as I worked to keep swarf out too. and depending on what is left, a copper crush washer on the plug may help with sealing.
Coming back to this with an update. Its been a while and I've done nothing as I've been waiting on some parts (filter, clutch drum, filler caps) from the local stihl dealer. I'm still waiting on the clutch drum, grr. Anyway I decided to have an investigation and got the saw out. Got the top cover off and the muffler and the piston and cylinder look perfectly clean to me. I will load photos shortly, although they aren't great. all clean though. So I went to the heli coil. plugged the plug hole with a cloth and went in with a cheap dremmel like tool and after grinding carefully halfway through the insert i snapped it off. All looked good except it was clear the taper/sealing surface at the top of the cylinder was in a bad way, chipped and mangled by the helicoil. hmm. I added a 0.5mm copper crush washer to the plug and did it up, and that was never going to seal, I could hear it hissing as i slowly pulled it over. removed the crush washer and did plug tight and it sounded better but a squirt of soapy water and pull the starter chord gave bubbles, big bubbles. Hmm. So I'm wondering if there is any sort of goo I could try to help get a seal, gasket cement, exhaust putty, that sort of thing, or some gasket type material? If not then I guess its machining or a new cylinder...so bodge up ideas are welcome here before I go that route.
bdc
top of piston
piston skirt
insert protruding and damaged cylinder plug sealing area before insert trim
somewhat chewed up sealing surface, after trimming the insert....oh dear
bdc
top of piston
piston skirt
insert protruding and damaged cylinder plug sealing area before insert trim
somewhat chewed up sealing surface, after trimming the insert....oh dear
I'm thinking Hylomar red might be worth a try, clean up first with a bit of white spirit. Any better ideas?
Still haven't had any problems with my aftermarket piston/cylinder on my 038 Magnum, great compression..
Which was it? I may need to go they route yet, although hopefully not. To upgrade to the Magnum means removing some material from the cylinder doesn't it? Something is needed to get the bolt holes to line up with the crank case? Anyway that is a different thread in the future..... For now I'll stick to trying to fix this spark plug hole.
That P/C is worth saving, piston looks great.
It might be worth looking at a timesert. They have a flange at the surface which might cover up the carnage. I'm not sure of the threads if they differ from the helicoil tap? They come in std. and oversize for really buggered up threads
The timesert kit is WAY expensive but if you can find a shop with the tools the inserts themselves are not too much cash. Check local machine shops.
I'd pull cyl. and throw some rings in when you fix it.
On a side note, maybe a smear of JB weld might seal it up?
http://www.timesert.com/html/bigsert_sparkplug.html
It might be worth looking at a timesert. They have a flange at the surface which might cover up the carnage. I'm not sure of the threads if they differ from the helicoil tap? They come in std. and oversize for really buggered up threads
The timesert kit is WAY expensive but if you can find a shop with the tools the inserts themselves are not too much cash. Check local machine shops.
I'd pull cyl. and throw some rings in when you fix it.
On a side note, maybe a smear of JB weld might seal it up?
http://www.timesert.com/html/bigsert_sparkplug.html
I would try the Permatex 518 stuff. Will seal the "tight" spots and wash away in other spots.
It is what many builders use when they do a gasket delete.
It is what many builders use when they do a gasket delete.
That permatex gasket compound looks like the same sort of stuff as Hylomar, Hylomar red is their thicker stuff, formulated for filling gaps.
I'm much more positive since pulling the muffler as the p and c looks great and although the plug hole is a mess I'm feeling confident. I'm going to try gasket compound first as its easy. If that doesn't work I'll try chemical metal/plastic padding/jb weld. A new insert is my fallback and the timesert sounds ideal if it comes to it. The helicoil looks good though and the plug tightens up very well now, I think it was simply too long for the hole.
Anyway, I'll get a tube of gasket compound and give it a try, but it's good to feel positive about this saw again..... Part of leaving it alone I guess was because I got very frustrated with it.
I'm much more positive since pulling the muffler as the p and c looks great and although the plug hole is a mess I'm feeling confident. I'm going to try gasket compound first as its easy. If that doesn't work I'll try chemical metal/plastic padding/jb weld. A new insert is my fallback and the timesert sounds ideal if it comes to it. The helicoil looks good though and the plug tightens up very well now, I think it was simply too long for the hole.
Anyway, I'll get a tube of gasket compound and give it a try, but it's good to feel positive about this saw again..... Part of leaving it alone I guess was because I got very frustrated with it.
I'm surprised a soft copper washer along with the sparkplug washer did not seal it up.
Another thought is to mill the sealing surface smooth again. I don't think you'd take enough off to have the plug sticking into cyl too far
Another thought is to mill the sealing surface smooth again. I don't think you'd take enough off to have the plug sticking into cyl too far
Gasket compound will seal a liquid leak but I wouldn't think it would hold 150lbs compression.
Maybe a thicker washer would work. I had a 14mm id, 20mm od washer Which was a good fit, but 0.5mm thick it was just thin, deformed and didn't seem to help at all. If I could find a 14*20 washer of a gasket material that could work...hmmm, off to Google.
The farmertec 52mm kits work great. Tiny bit of demel work and drill work to line up the holes. Muffler modded, meteor piston, caber rings, base gasket deleted and retuned and this set up hangs with a 372xp.. which I thought was pretty impressive... that is my experience and my two pence.
I am still waiting for an oem 52mm for my second 038av to mag project, but until I get one I'll be happy with this farmertec cylinder.
Try using two (or three) of the same copper washers under the plug sealing washer. If that works store some extras with your spare spark plugs.
