Stihl 031 Fuel Tank Vent Mod

[anatoli031585]

So yes the 030, 031, 032 vented caps came in a few varieties, can no longer get individual own parts, but you are able to get proline am replacement cap assemblies, we know this...

Well paying $30+ for an am cap on a saw I paid $50 for doesn't sit well with me and I haven't seen anyone do this so I figured why not. Today we drill!

So the idea was to drill a single hole in the tank, fit a grommet, run a modern Stihl vent of a line that was both concealed like the fuel line, under the top cover, and routed into the carb box which is the cleanest place on the saw.

So I take the saw apart, empty the fuel tank of some but not all the older fuel. Figuring that no matter how careful I am, drilling would get in the tank and I would use it to help carry them out before flushing with fresh. Picked my spot I thought would work far enough from the edges and drilled. Lol, my first mistake.

In my exuberance and in a rare lapse in my standard regiment (pre plan every step, measure 5x, cut or drill once) , attempting to bang this out in 15 mins that I had available, discovered my chosen spot was less than ideal. There I am drill and blow (the drillings away) nice and slow, wondering why its so thick, haha, guess I have to come back to this one, its no longer a 15min possibility....


What you're looking at is this genius drilling partially into the fuel tank and partially into the cavity for the machine screw that fastens the 2 tank halves together. Doh!


The grommet I wanted to use had a wide profile so that placement would have been perfect, or so I thought, in actuality, I should have gone over 1/4"-5/16" to the right, then down 5/16"-3/8". I learn later this position I've drilled gets more troublesome....

So I'm back from whatever chaos I that demanded my attention now committed to the task. Well options are now limited so lets see here what I've got to straighten this out. Interesting side note: the event that got me into Stihl saws has paid off again. I was at the scrap yard one day with a load when a truck having an awful time attempting to unload the massive dump bed about 30 yr dumpster size kept pulling up, backing up fast, slamming on the brakes next to me. Finally the load released and there was a perfect compacted metallic rectangle next to me. Oh the wonderful things contorted and mangled in that magnificent quagmire! Like someone's entire shop all jammed into a steel casserole. I immediately noticed several stihl saws. The yard had just instituted a new policy prohibiting anyone from buying things anymore, after a storied history of charging you 4x the scrap price prior to that for anything you might want.... I was determined to save what I could, using my truck to block the sight lines, I had 30 seconds. I saved an 024 avwb and 028 wb. The others were top far in, damn! I had a single additional opportunity to grab a very heavy metal case and hid them on my truck. Long story long, the case had about 80 lbs of tiny brass fittings, of which, I took a little of every type to keep with my small engine stuff, glad to have it on hand now years later.... Dont mind the 064 in the background, she's an attention hoe.....



So I find a nice long elbow and the epoxy, convinced that it will just be easier to fill in the screw cavity. If I ever have to split that case, then I figured ill get a parts saw tank long before that day comes...



But wait, isn't that a large cavity to fill and seal the tank from pressure changes, yes, its true...



What to do, hmmm, I started ripping of the cotton applicator tips I have for precision cleaning, dumping them into the epoxy mix, as I pulled them apart a little, then mixed it in, leaving some to the side without any.

Continued on next post so I can attach the other pictures........

 

[anatoli031585]

I then took the clean epoxy and put it on all the edges, took some with the cotton and wrapped it around the brass elbow. This is after I used my carbide dental bit to get to bare metal inside the cavity and anywhere epoxy would go, cleaning it with brake cleaner as well as spraying out the tank for fuel residue and drillings + dremel debris.



Then I fit the elbow, turned it in a similar orientation to the fuel line but angled more conservatively making sure u wasn't going to miss my target. Then packed the cavity, packed the top, sealed with non cotton epoxy, licked my (little bit dirty) finger tip and smoothed it out, took it to my paint drying rack set over top a baseboard heater, let it ride for 24 hours.



So I went to put it on the drying rack, what's this? That won't do at all!



So I spent a good amount of time excavating the corroded aluminum with the carbide burr, just in time too, can i get some more epoxy, please?!



This time I used a cleaner finger! To the drying rack!

Continued for last pictures in next post...

 

[anatoli031585]

So a day later, I was eager to have the saw back, down the road, yes, ill do a full paint job, not today.... Off white nail polish on all the epoxy and some other spots missing paint, then back together. Final thoughts: im glad I turned the angle of the brass elbow but had it been in the better spot, would have been even better. So its a little tight but the vent ended up exactly where I wanted it, above the carb, and there are no kinks. Its all protected and tucked under the top cover handle assembly too. And It no longer stops running halfway through so it worked. No leaks either, but time will tell...



I couldn't help myself, the original bar Stihl oem 1983 needed a new chain, a good dressing, and despite the paint being almost gone entirely, after the dressing and cleaning, was in excellent condition, so something else was on the dry rack to for that epoxy cure day, a little lube, et voila, I did the muffler with high heat ceramic primer and paint, and there's the bar, another one of my experimental paint jobs... Opinions?