BoneShaker...

[cedarshark]

Working on a 041AV. It runs well but will rattle your teeth It rattles to the point of backing out the bolts that hold the muffler to the cylinder. I think I have that problem fixed w/ lock washers and Loc-Tite, but the third bolt(to the saw frame) has destroyed the threads on the bolt & bolthole. I am unsure which way to repair this: Would you ?

1) Chase the existing threads(if any) with a tap the same size as the original bolt ?

2) Drill and install a Helicoil ?

3) Drill, tap and install the next bigger size ?

I feel this bolt is really necessary to keep this muffler from vibrating loose again. The muffler is big and heavy and needs the support from that bolt. Thanks in advance...

 

[scotvl]

I would try options 1 3 2 in that order, but if the saw is important to you I would take it to a machine shop and have it done by a pro.

 

[SpaayDawg]

2 out of my 3 041's have had this same problem. Both are drilled and tapped for a 6mm with RED loctite instead of a 5mm bolt. Haven't had a problem since. Muffler to cylinder bolts have red loctite on them too, blue for cylinder to crankcase bolts tho.

 

[cedarshark]

2 out of my 3 041's have had this same problem. Both are drilled and tapped for a 6mm with RED loctite instead of a 5mm bolt. Haven't had a problem since. Muffler to cylinder bolts have red loctite on them too, blue for cylinder to crankcase bolts tho.

Jeff...I have never tapped aluminum/magnesium. Did you drill/Tap for the 6mm bolts yourself or have it done? My Tap/Die chart says you can drill a 7/64 hole for a 6mm bolt. I don't own metric drill bits but have a metric tap/die set coming.

 

[cedarshark]

I would try options 1 3 2 in that order, but if the saw is important to you I would take it to a machine shop and have it done by a pro.

I intend to sell the saw but do not want to transfer a problem to a new owner. Is there something magic about drilling and tapping aluminum or magnesium ? Thanks !

 

[bobt]

No special problem tapping magnesium, just remember to back off the tap to break off the "burr" every half turn or so. You may not have access to a helicoil tool, but we always installed helicoils in the saw shop when confronted by a stripped screw hole. It is a permanent fix. It's about a ten minute job, not expensive, and just the best solution in my opinion.

Bob

 

[Paul001]

Another option, we use to use on saws like the S-25AV, is wire ties. If you have the big head allen's, drill both and wire tie them together.

 

[SpaayDawg]

Jeff...I have never tapped aluminum/magnesium. Did you drill/Tap for the 6mm bolts yourself or have it done? My Tap/Die chart says you can drill a 7/64 hole for a 6mm bolt. I don't own metric drill bits but have a metric tap/die set coming.

I don't know if metric drill bits are available either, like you my chart states to use 7/64 bit. Go slow, use lots of lube (WD-40 works well) and make sure it's straight. If you're worried about being straight with a hand drill find someone that's got a drill press, I use a drill press vise with chainsaw stuff to make sure it's aligned.

 

[iowa]

It shouldn't vibrate like that. You may have a bent crank or messed up clutch!

 

[cedarshark]

No special problem tapping magnesium, just remember to back off the tap to break off the "burr" every half turn or so. You may not have access to a helicoil tool, but we always installed helicoils in the saw shop when confronted by a stripped screw hole. It is a permanent fix. It's about a ten minute job, not expensive, and just the best solution in my opinion.

Bob

Thanks and I will heed your advice. I am leaning toward the helicoil and obviously it has applications in a chainsaw environment. I was worried about the vibration shaking the helicoil loose, but this does not appear to be the case. I know the auto parts shop owner here pretty well so I think I can borrow the tool.

 

[cedarshark]

It shouldn't vibrate like that. You may have a bent crank or messed up clutch!

I agree but I have seen several threads with a lot of the owners of these saws complaining about similar problems(vibration). Even with the AV rubbers in great shape....this saw will walk out of the shop if left idling on the floor ! Reminds me of my 4-20 Homelite(No AV). I received the 041 w/out a clutch, bought a used replacement and waiting on the sprocket needle bearing to re-assemble. I want to get the muffler secured before running the saw again. To replace/tighten the muffler to cylinder bolts....you have to disassemble the top half of the motor...PITA.

 

[cedarshark]

I had a vibration question but failed to mention it in my original post. I noted that this saw has a horizontally orientated cylinder rather than the more recent Stihls with a more vertical design. Could this contribute to the vibration ? If it doesn't make any difference which way the cylinder/jug is oriented...why do you think Stihl(and others) went to the upright design ?

 

[SpaayDawg]

I agree but I have seen several threads with a lot of the owners of these saws complaining about similar problems(vibration). Even with the AV rubbers in great shape....this saw will walk out of the shop if left idling on the floor ! Reminds me of my 4-20 Homelite(No AV). I received the 041 w/out a clutch, bought a used replacement and waiting on the sprocket needle bearing to re-assemble. I want to get the muffler secured before running the saw again. To replace/tighten the muffler to cylinder bolts....you have to disassemble the top half of the motor...PITA.

:agree2: Yeah, they could have made it a little easier to get to. But, I'm sure the original designers didn't intend for the muffler to be taken off of the saw much.

I had a vibration question but failed to mention it in my original post. I noted that this saw has a horizontally orientated cylinder rather than the more recent Stihls with a more vertical design. Could this contribute to the vibration ? If it doesn't make any difference which way the cylinder/jug is oriented...why do you think Stihl(and others) went to the upright design ?

There are better flow characteristics from a cylinder will opposed intake/exhaust ports instead of having both on the same side of the cylinder. The "breathe" better.

 

[bobt]

Cedarshark,,,,,If he has the tool in 5mm then the heli is a very good choice. Maybe you can just take the saw in to him, and he will do it for you. Either way, have him explain the whole process, drilling, tapping for the heli, and installing the heli. You want the helicoil to be at least deep enough so it is flush with the surface, even a half a thread lower is ok as well.

We sold mostly Stihl 041's back in the day, and vibration was not as bad a problem as most are led to believe,,,,,,but, well, I would not recommend letting them idle on a concrete floor!!!! Haha! Yep, it would walk away from you!!!!!!

Bob

 

[cedarshark]

:agree2: Yeah, they could have made it a little easier to get to. But, I'm sure the original designers didn't intend for the muffler to be taken off of the saw much.



There are better flow characteristics from a cylinder will opposed intake/exhaust ports instead of having both on the same side of the cylinder. The "breathe" better.

SpaayDawg.... The above makes sense. It would be very difficult achieve opposing intake/exhaust with a horizontal cylinder. Thanks

 

[cedarshark]

Cedarshark,,,,,If he has the tool in 5mm then the heli is a very good choice. Maybe you can just take the saw in to him, and he will do it for you. Either way, have him explain the whole process, drilling, tapping for the heli, and installing the heli. You want the helicoil to be at least deep enough so it is flush with the surface, even a half a thread lower is ok as well.

We sold mostly Stihl 041's back in the day, and vibration was not as bad a problem as most are led to believe,,,,,,but, well, I would not recommend letting them idle on a concrete floor!!!! Haha! Yep, it would walk away from you!!!!!!

Bob

The HeliCoil kit w/ handle, special tap and 6 coils is $34. The instructions mandate that the small tab at the end of the coil MUST be broken off after the coil is installed. This would appear to be a problem in a blind(open on the top only) tapped hole. As I have a metric tap/die in the mail...it would seem to make more sense to just bore the old hole to 7/64s and tap for 6mm. Had I not purchased the tap/die set, the helicoil would have made more sense.

 

[leonbentz]

A vibration issue like that sounds like a flywheel out of balance. Are there any missing fins?

 

[cedarshark]

A vibration issue like that sounds like a flywheel out of balance. Are there any missing fins?

I assumed same thing as you....pulled the cover and the flywheel is perfect, no broken fins and very stable on the crankshaft. I am waiting on a clutch needle bearing so I can run the saw with the clutch installed. I don't think this would cause the vibration but .... Thanks.

 

[RandyMac]

Verticle cylinder chainsaw motors have been around for over 60 years, nothing "recent" about them. As for cross flow horizontal motors, McCulloch and Remington had a long run with several models, starting in the mid 1960s, I'm sure there were other makes as well.
If your chainsaw is shaking itself to pieces, it could be a design flaw or a crankshaft problem, flywheel and clutch included.

 

[indiansprings]

You ought to take it to your friends, my local auto shop owner has a drawer full of partially used heli-coil kits, he sells them to me when I need them for 3 bucks a coil and loans me the tool and tap. Could save you some money.
I've had great luck with heli-coils on the farm, never had one fail that was installed properly. Used one this fall on my son's eldebrock intake when he stripped one of the hole used for the thermostat cover, so far it's worked like a charm.