OEM rings or aftermarket? I just wish I could have a super Stihl shop where I could walk in and buy why I want. I freaking hate waiting for parts.
028 AV Super Wood Boss
- Thread starter K5krawler
- Start date
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OEM rings or aftermarket? I just wish I could have a super Stihl shop where I could walk in and buy why I want. I freaking hate waiting for parts.
Officer's Match
Addicted to ArboristSite
I have had problems with the on/off/choke control on both of my 028AV Supers. Must be me.
don't get too exited on compression numbers... your gauge could be reading high and his reading low. unusual to get 170 psi from an old used saw.
it's nice if you have a known to be correct high quality gauge like a Snap-on set.
just scored an 028AV too... looks very close to new with low hours. was running fine, then decided to stumble. have not torn into it yet.
it's nice if you have a known to be correct high quality gauge like a Snap-on set.
just scored an 028AV too... looks very close to new with low hours. was running fine, then decided to stumble. have not torn into it yet.
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Some Update Pictures
This saw has had a rough life. I am trying to clean it up as best I can with out splitting the case and getting in too deep.
Really Bad Air Filter
Cleaner Plastic
Ashamed this has this much pitting on the cover. Otherwise it's in good shape.
This saw has had a rough life. I am trying to clean it up as best I can with out splitting the case and getting in too deep.
Really Bad Air Filter
Cleaner Plastic
Ashamed this has this much pitting on the cover. Otherwise it's in good shape.
trappermike
ArboristSite Guru
The 028 was one of the best saws Stihl made. Sounds like due to it's age it has an air leak somewhere. One common place on the Stihl's was the the rubber boot connecting the carb to the intake port,check it for a crack or a tear.
Good luck they don't make saws like those anymore!
Good luck they don't make saws like those anymore!
Yeah, I'd check the intake boot real close. If ya got her down that far ya might as well re-ring it. Piston looks OK, best I can tell from the pic. I like the Caber brand real well. Northwoods ( AS sponsor ) has fast shipping and a good price.
Intake Boot
I've checked that and the impulse line several times for tears. It all looks like it is in pretty good shape. The fuel line was a different story. It was split and cracked in several places. The carb adjustment screws were defiantly out of whack as well. I think the L was about 2 turns out...I have no idea why.
I've checked that and the impulse line several times for tears. It all looks like it is in pretty good shape. The fuel line was a different story. It was split and cracked in several places. The carb adjustment screws were defiantly out of whack as well. I think the L was about 2 turns out...I have no idea why.
Piston & Cylinder
I hope you guys don't mind more pictures to look at. I pulled off the cylinder and found some evidence of aluminum transfer and what looked to be the beginning of a lean failure. I was able to get the aluminum transfer off and cleaned the cylinder with scotch brite. I will re ring it after I get it back together and running better. For now this is how it is going to stay.
Piston Scoring
Small amount of aluminum transfer. This was cleaned up with some acid and a touch with the wire brush. Washed out the cylinder and it doesn't look too bad.
Piston post wash. You can still see the cross hatch in the cylinder, mighty nice!
Scotch brite on the piston cleaned it up nicely
Base gasket looked good and bearings seemed to be okay on the bottom end. I am still thinking the lean side was coming from the really loose spark plug. Just waiting on some parts that should be here this week and hopefully will have it going before the weekend! Remember I will re ring this saw later.
I hope you guys don't mind more pictures to look at. I pulled off the cylinder and found some evidence of aluminum transfer and what looked to be the beginning of a lean failure. I was able to get the aluminum transfer off and cleaned the cylinder with scotch brite. I will re ring it after I get it back together and running better. For now this is how it is going to stay.
Piston Scoring
Small amount of aluminum transfer. This was cleaned up with some acid and a touch with the wire brush. Washed out the cylinder and it doesn't look too bad.
Piston post wash. You can still see the cross hatch in the cylinder, mighty nice!
Scotch brite on the piston cleaned it up nicely
Base gasket looked good and bearings seemed to be okay on the bottom end. I am still thinking the lean side was coming from the really loose spark plug. Just waiting on some parts that should be here this week and hopefully will have it going before the weekend! Remember I will re ring this saw later.
If you can no longer see the machining marks on that piston, you probably took it down too far cleaning it up (it IS aluminum) and may want to consider a replacement since you've already gone this far with the project.
I'd at least put a micrometer to it to see what kind of slop to expect using it "as is" if that's the way you're gonna go. You may be surprised.
Good job on the jug. Keep us 028 guys posted!
Poge
I'd at least put a micrometer to it to see what kind of slop to expect using it "as is" if that's the way you're gonna go. You may be surprised.
Good job on the jug. Keep us 028 guys posted!
Poge
trappermike
ArboristSite Guru
A loose plug wouldn't make it run lean. Nice job cleaning up the pist. and cyl. though!I think that piston will be fine and run for a long time yet,even if a little loose.
Main thing is why was it lean? Probably the high speed screw set a bit lean,but maybe other things,check your carb diaphragms aren't old and stiff,clean your fuel filter,check your fuel line and impulse hose for tiny holes or cracks. An easy way to test hoses-plug one end with your finger,then suck on the other end and see if your tongue stays stuck to it with suction,if so it's ok.
Throw some new rings on,check your carb etc. and you should be fine.
Main thing is why was it lean? Probably the high speed screw set a bit lean,but maybe other things,check your carb diaphragms aren't old and stiff,clean your fuel filter,check your fuel line and impulse hose for tiny holes or cracks. An easy way to test hoses-plug one end with your finger,then suck on the other end and see if your tongue stays stuck to it with suction,if so it's ok.
Throw some new rings on,check your carb etc. and you should be fine.
2 More Pictures
I checked using the trappermike tongue and suck technique:msp_w00t:. They all seemed alright. I did already order a new fuel line because it was cracked (but not all the way through) and a new filter because it's just good practice. As I said earlier the L side was not the typical 1 1/4 - 1 turn out. It was more like 2 - 2 1/4, I don't know why but that's what it was when I screwed the needles down.
Okay onto some more pictures. So I know everybody wants me to put new rings in the saw etc etc....well I will just not right now. So earlier I showed some pictures of the piston and cylinder with some aluminum transfer. We had kind of tossed around the idea of a lean failure because of the high speed issue that I spoke of. Well this might be the reason for the failure, earlier today I was surfing around on Madison's website and I saw some stuff on heat related piston failure and I went down to compare my piston to the piston picture on their website. I THINK I might have found the problem, the saw was real dirty and if the fins are dirty and don't allow the heat to dissipate you could suffer a hot spot in the cylinder and partial piston failure in localized areas. So I took some pictures of the cylinder and I think it was from that.
Notice the discoloration around the exhaust port. This was where the piston had failed.
If you can see on the 028AV Super how close the cylinder fin is to the side of the case. Now put a muffler right by this side and we might have found our problem. Only 20 yrs of grease, oil, and wood chips added to the problem.
K5
If you can no longer see the machining marks on that piston....
Good job on the jug. Keep us 028 guys posted!
The Piston still has the machining marks on it. I know it doesn't look like it but they are still there. Thanks I'll keep the 028 crowd happy with more pictures.
Poge
I checked using the trappermike tongue and suck technique:msp_w00t:. They all seemed alright. I did already order a new fuel line because it was cracked (but not all the way through) and a new filter because it's just good practice. As I said earlier the L side was not the typical 1 1/4 - 1 turn out. It was more like 2 - 2 1/4, I don't know why but that's what it was when I screwed the needles down.
Okay onto some more pictures. So I know everybody wants me to put new rings in the saw etc etc....well I will just not right now. So earlier I showed some pictures of the piston and cylinder with some aluminum transfer. We had kind of tossed around the idea of a lean failure because of the high speed issue that I spoke of. Well this might be the reason for the failure, earlier today I was surfing around on Madison's website and I saw some stuff on heat related piston failure and I went down to compare my piston to the piston picture on their website. I THINK I might have found the problem, the saw was real dirty and if the fins are dirty and don't allow the heat to dissipate you could suffer a hot spot in the cylinder and partial piston failure in localized areas. So I took some pictures of the cylinder and I think it was from that.
Notice the discoloration around the exhaust port. This was where the piston had failed.
If you can see on the 028AV Super how close the cylinder fin is to the side of the case. Now put a muffler right by this side and we might have found our problem. Only 20 yrs of grease, oil, and wood chips added to the problem.
K5
trappermike
ArboristSite Guru
A seizure at the exhaust port is almost always lean seizure. This is because as the mixture gets leaner the ex. temp. soars higher,burning the oil away from the piston exposed to the flame in the port,and the flame temp. is almost high enough to melt aluminum.
Look for a lean seizure cause or it may happen again.
I wouldn't re-use the rings,I've been bitten before(very expensively!),the rings can become very brittle,and promptly break not long after repairing the motor.
028's are too good to loose them!
Tip-Use a tablespoon of Castor oil in the fuel tank as a breakin additive.Yea,the stuff from the drug store,I use it to break in all my rebuilds,excellent stuff...
Look for a lean seizure cause or it may happen again.
I wouldn't re-use the rings,I've been bitten before(very expensively!),the rings can become very brittle,and promptly break not long after repairing the motor.
028's are too good to loose them!
Tip-Use a tablespoon of Castor oil in the fuel tank as a breakin additive.Yea,the stuff from the drug store,I use it to break in all my rebuilds,excellent stuff...
Officer's Match
Addicted to ArboristSite
Great stuff you can learn around here. :msp_thumbup:
I'll agree with you. However, the failure was also on the intake side as well. Along with the failure on the intake side there was a lot of dirt on that one shot I posted. It took a wire brush and brake clean to remove it from the exhaust side. The intake just suffered from dirty fins.
I agree with the rings...My 031 that I ported I felt the same way when working on it!
The oil, seems like it's something mom would give you when you were all "stuffed up" :msp_biggrin:
Great thread going so far :msp_thumbup:
The 028 surely seems to be a real popular model. In just the past couple of weeks I've had 3 show up, and they've all been different. Not to distract from your thread but I figure this may be a good place to ask as all the 028 guys are probably in here - Do you know the difference between the different models? 028, WB, Super, AVEQ... etc...? I understand WB is woodboss, AV is anti-vibe, but what's the other stuff? Are there power/weight differences? I see yours has 3 different designations on it, sounds like a fully loaded model
The 028 surely seems to be a real popular model. In just the past couple of weeks I've had 3 show up, and they've all been different. Not to distract from your thread but I figure this may be a good place to ask as all the 028 guys are probably in here - Do you know the difference between the different models? 028, WB, Super, AVEQ... etc...? I understand WB is woodboss, AV is anti-vibe, but what's the other stuff? Are there power/weight differences? I see yours has 3 different designations on it, sounds like a fully loaded model
TJ-Bill
Addicted to ArboristSite
I'll be picking up a chain tonight for my 028 Av Super rebuild and running it through it's paces. I had fun rebuilding the saw even thought I've got more$$ into it then it's worth. Worst part is I think I have a small hole in the fuel tank somewhere..
They're great little saws, have fun.
They're great little saws, have fun.
trappermike
ArboristSite Guru
As a Stihl mechanic for a long time I think the 028 and the 038 were the best saws they ever made for durability.
Your rebuild was worth it because you'll not buy a new saw with the same durability and solid design. Good work.
Your rebuild was worth it because you'll not buy a new saw with the same durability and solid design. Good work.
Clarkbug
ArboristSite Operative
Great thread going so far :msp_thumbup:
The 028 surely seems to be a real popular model. In just the past couple of weeks I've had 3 show up, and they've all been different. Not to distract from your thread but I figure this may be a good place to ask as all the 028 guys are probably in here - Do you know the difference between the different models? 028, WB, Super, AVEQ... etc...? I understand WB is woodboss, AV is anti-vibe, but what's the other stuff? Are there power/weight differences? I see yours has 3 different designations on it, sounds like a fully loaded model
EQ stands for electronic quickstop.
I cant be of much use for any of the other stuff, thats my one little tidbit of info.
Im also in the process of a 028 super rebuild, but life has gotten in the way so it sits on my bench in pieces, glaring at me to put it back together and make it useful again.
Everything together expect the flywheel, waiting for a key.
I am thinking my key and ground wire will be here tomorrow.
I got the new fuel line and filters installed. Also got new AV bushings, is it common for the saw to have torn AV bushings?
Fuel line and Intake hose
New AV bushings in the front. Both were torn or badly cracked. I guess 20 yrs is a long time to ask rubber to hang around.
Muffler and chainbrake
Top shroud and top AV bushing. That AV bushing gave me some trouble.
I am thinking my key and ground wire will be here tomorrow.
I got the new fuel line and filters installed. Also got new AV bushings, is it common for the saw to have torn AV bushings?
Fuel line and Intake hose
New AV bushings in the front. Both were torn or badly cracked. I guess 20 yrs is a long time to ask rubber to hang around.
Muffler and chainbrake
Top shroud and top AV bushing. That AV bushing gave me some trouble.
More...
New fuel line and cleaned and readjusted carb back in.
Choke
TIP OF THE DAY!!!! Magnetic screwdriver helps install this small screw on the kill switch ground.
It holds it there until you can get the screw aligned into the hole.
Ground
Finished for now until more parts come.
New fuel line and cleaned and readjusted carb back in.
Choke
TIP OF THE DAY!!!! Magnetic screwdriver helps install this small screw on the kill switch ground.
It holds it there until you can get the screw aligned into the hole.
Ground
Finished for now until more parts come.
