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Stihl 038 Gas Tank

djg james

djg james

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I'm replacing the original metal gas tank on my Stihl 038 with one of those aftermarket ones.

I just fought to get the manifold hose and clamp back on. I was ready to put the vibration isolator screws in, to mount the tank to the saw, and it looks like the holes in the plastic tank aren't tapped. Anyone replace a gas tank with a plastic aftermarket tank and run into a similar situation?

I guess I'm going to have to find what metric size the bolts are and then find a tap.
Any idea what size bolts they are?

I guess use a tapering tap first and then finish up with a bottoming taper?
 
Mad Professor

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I'm replacing the original metal gas tank on my Stihl 038 with one of those aftermarket ones.

I just fought to get the manifold hose and clamp back on. I was ready to put the vibration isolator screws in, to mount the tank to the saw, and it looks like the holes in the plastic tank aren't tapped. Anyone replace a gas tank with a plastic aftermarket tank and run into a similar situation?

I guess I'm going to have to find what metric size the bolts are and then find a tap.
Any idea what size bolts they are?

I guess use a tapering tap first and then finish up with a bottoming taper?
If I remember? jug and string trick.jpg intake installed.jpg

OEM tanks had a helicoil insert. They replaced threaded M6 screws that used the helicoils, with self tapping down the road.

The screws should be self tapping, unless you install helicoils

Clamp the manifold to the cylinder them wrap a piece of yarn around it. Use the yarn to pull the boot though the tank housing, pull the tag on on the yarn and you are done.
 
djg james

djg james

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Thanks, a video I watched did it the direct opposite. Pushed the manifold tube over the nipple last, then clamp it. Wish I had thought of your way first, looks easier.

The walls of the holes are smooth, no threads. So I guess I should just tap them? I bought a tapered tap at the local Ace; they did not have a bottoming tap. Do I need one?
 
Mad Professor

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Thanks, a video I watched did it the direct opposite. Pushed the manifold tube over the nipple last, then clamp it. Wish I had thought of your way first, looks easier.

The walls of the holes are smooth, no threads. So I guess I should just tap them? I bought a tapered tap at the local Ace; they did not have a bottoming tap. Do I need one?
PITA to tighten the manifold clamp that way.

The string/yarn trick is mentioned in the Stihl shop manual. If I remember they also suggested an orientation on the clamp, that is where the screw part is .
 
alexcagle

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Please don't leave me hanging.
Stick a wood screw, or similar in there for now, until you get the right screw if you are itching to use it. (Ps; I didn't advise that)...
The reason for an extra long head on the screw and the deep cup, is to add a bumper or limit stop so that in the event the handle gets twisted or pulled too hard, it doesn't yank the intake boot causing it to rip.
 
djg james

djg james

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At a Stihl dealer, Ebay, or one of the Chinese imitation places that sells every single component for an 038, but in gleaming "Harbor Freight" quality quantity.
Thanks, I didn't see much on ebay or Amazon. I'm looking for cheaper than $5/2. That's ridiculous. Maybe I'm not being reasonable, though. Maybe I'm not using the right keywords in my search either. I'm going to try the local farm store that used to work on my saws.
 
djg james

djg james

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.....
The reason for an extra long head on the screw and the deep cup, is to add a bumper or limit stop so that in the event the handle gets twisted or pulled too hard, it doesn't yank the intake boot causing it to rip.
I'm not sure what you mean by "extra long head" and the "deep cup". I'm guessing the head on the screw is what you're talking about. These are the screws that hold the vibration isolators in place.

Edit: And I'm guessing these are the only four points that I need these coarse thread self tapping screws to attach to the new tank. Damn plastic tank; I wish someone made a metal aftermarket tank for even twice the price of plastic. OEM way too expensive.
 

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alexcagle

alexcagle

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PITA to tighten the manifold clamp that way.
.
My Tech tip: (Evaporating lube)
Try this, you will be amazed....
When sliding intake boots over the intake connection on a cylinder;
I use a small squirt of lacquer thinner on cylinder's intake connector right before you push on the boot.
The boot will practically jump on there, as the lacquer thinner makes the rubber slippery for about 10 seconds until it evaporates.
Plus you are less likely to poke a hole in the boot by forcing it hard like a virgin on prom night......
I use a WD40 manual squirt bottle for the lacquer thinner, but an empty windex bottle will work. Make sure and re-label it though
 
alexcagle

alexcagle

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I'm not sure what you mean by "extra long head" and the "deep cup". I'm guessing the head on the screw is what you're talking about. These are the screws that hold the vibration isolators in place.

Edit: And I'm guessing these are the only four points that I need these coarse thread self tapping screws to attach to the new tank. Damn plastic tank; I wish someone made a metal aftermarket tank for even twice the price of plastic. OEM way too expensive.
The upper tank connector by the boot is the only one that utilizes the special long head screw. The other three AV mounts are the regular head screws with AV plugs.
Screenshot_20200228-083551.jpg
Don't use screws that are too long either.
Check your hole depth with a paper clip or something.
(Not advised on prom night)...lol
 
djg james

djg james

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Thanks, I appreciate your help walking me through this.
In my photo on the left is one of the three screws (bolts) that hold the handle's two vibration isolators up by the muffle and the other on top on the right.

The screw on the right is the long head screw you're talking about (on the left of the saw).

All my bolts are M6 x 1.00 (coarse) threads for the tapped holes in the metal tank.


I now need Coarse Self Tapping Screws M6 of appropriate length?

And I only need regular Torx heads like shown in your picture for the first three mentioned?
 

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Mad Professor

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If you can find a couple of beat up 038 carcasses (those too far gone to fix), they are real handy to have to scrounge hardware off of. And the hardware is all OEM/quality. To bad OP could not locate a OEM tank assy.

Even if the parts saw is a different model, lots of stuff like screws gas/oil caps will interchange. You just need room to store the junk
 
djg james

djg james

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Almost done. Hands haven't been cooperating and I had to order parts. Another question. I got a new grounding wire but since it's been awhile since I removed the broken one, I don't remember where it was connected to. See photo. I know the lug on the new (black) ground wire attaches under the cover bolt on the left (black arrow). But I'm not sure about the other end (pin) of the wire. I fished the black wire from the ignition the hole in the new gas tank and placed the pin (red arrow) into the trigger spring. I thought that's where the pin on the ground wire should go. Any help is appreciated.
 

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