Stihl 038 Mag Breakdown

[CrystalRiver1]

Hey Guys,

I'm a novice at chainsaw mechanics, BUT per Randy...I'm starting this thread to get better acclimated with that.
Here is some rather general info from this recent saw purchase of this 038 Mag that looked rougher than a night in jail initially.

I'm all Klutz & Neatnathrathal at most things mechanical, but I did take some pics of my initial discoveries.
A. Saw was supposedly in need of a rebuild per older seller...says it won't fire.
B. Saw won't fire...pull rope came out about 6-8 inches and stops.
C. Removed pull cord assembly---pull cord snapped back in zero flat and pulls easily off the saw & attached.
D. Piston slides up & down easily almost likes its greased.
E. Piston looks ok...can't see any obvious scoring , BUT other than looking @ other scored piston pics on saw sites...I just don't have any experience in judging its overall condition.
F. The chain sprocket will not rotate or budge.
G. Carb looks clean.
H. Have not looked at fuel, impulse, or other lines.
I. Massive stink bug crawls out from behind the crankshaft...looked a tad tipsy! lol
J. Pretend to toss stinkbug on wife...wife threatens to claw my eye sockets...destroy stinkbug...retire for the night.


I'm kinda tempted to slam it back together, put my ethanol free fuel, bar oil in it and see will it light up.
Any thoughts or ideas you guys have is appreciated.
BTW...headed out of town for few days...will be back in pocket Mon or Tue next week.

Thanks
Reg

 

[CrystalRiver1]

More pics from the 038Mag.

 

[Wolverine]

I'd start with a vac/pressure test 1st, compression after that. If you're unfamiliar with those -

Welcome to the forum!

 

[drf256]

I have more questions than answers.

That piston looks ok. Is the carb missing the throttle plate, or is that an illusion?

The clutch not turning at all. Is the brake on?

Do you have a compression tester with a shrader valve at the tip? Not sure what a "greased" piston means. Is that almost no compression, or just smooth compression?

From what I see, I'd Block the ports off. Give it the mineral spirits with a small brush/soap and water/compressed air treatment, change the plug, and try to run it.

BTW, you need a new airfilter. That one won't do much.

 

[huskihl]

Also, pull the sparkplug, reconnect to the plug wire, lay it on top of the cylinder to ground it out, and with the switch on pull it over to check for spark.

 

[Al Smith]

Stop already .The carb has a throttle plate and the choke is in the bottom half of the filter which by the way has the flocking sucked out of it ,needs a new filter .All that's left is the wire screen which really won't filter much of any thing.The choke is activated by the plastic rod which goes from the control button to the choke .

The av mount is missing a bolt and could rotate on power which will stretch the intake boot and might tear it .Torn bad enough it will never start .Toss some gas in it a give it a tug or 20,might light right off --or not.Don't get some bright idea of using starting fluid,almost certain way to cook it .

 

[Mastermind]

I moved this to the main saw forum.

Welcome aboard good sir........I like your sense of humor.

 

[Simondo]

Hi there Sir.
Hope you dont mind me suggesting (if you have not done so now) before you get to taking things apart and looking around the saw to try and figure out what is or isn't there ...split or not split..cracked..busted.. warn out.....that you give yourself a fighting chance to see what your up against and clean the saw down fully.
Its the very first thing I personally do to asses what is going on . Makes Vac/pressure test and other investigations easier and crap wont get where crap shouldn't get causing issues further down the line.

 

[CrystalRiver1]

I moved this to the main saw forum.

Welcome aboard good sir........I like your sense of humor.

Much obliged my friend...
Anxious 2 slam the muff back on the 390 and she how she howls!!

 

[CrystalRiver1]

Hmm...taking it all in for the moment...I'll put my hands back on it Mon-Tuesday...thanks for the feedback.

 

[CrystalRiver1]

Hi there Sir.
Hope you dont mind me suggesting (if you have not done so now) before you get to taking things apart and looking around the saw to try and figure out what is or isn't there ...split or not split..cracked..busted.. warn out.....that you give yourself a fighting chance to see what your up against and clean the saw down fully.
Its the very first thing I personally do to asses what is going on . Makes Vac/pressure test and other investigations easier and crap wont get where crap shouldn't get causing issues further down the line.

You have a phenomenal grasp for the obvious...which eludes me at times...thanks Simondo.

 

[jb-chainsaws]

If I know I'm going to do a full strip, I remove the carb, coil and muffler, stuff something into the ports to stop any lumps getting in then give it a few rounds of degreaser and hose pipe.

When you're doing the strip (once it's clean) separate the case from the handle via the 4 AV mounts, intake boot loosened and slid away from the jug and impulse Line removed.

Things I'd always do on a saw of this caliber are:

- caber piston rings
-genuine crank seals
-genuine impulse line
-genuine fuel line and pickup
-Cylinder base gasket delete and replaced with yamabond etc - I like to apply a constant thin line of it around the base with a syringe and a fat needle, makes things a damn sight less messy.

Check the crank bearings once it's stripped down for play, a tiny bit of side to side play is okay but they should be tight up and down, and with the seals removed should spin nice and free with no resistance or lumpiness.

The carb may be alright, but always best to strip it and replace the gaskets and diaphragm - it'll be wearing a bing carb and the kits are available on eBay.

Don't want to step on anyone's toes or teach anyone how to suck eggs, but there's a wealth of information on here so if there's anything you need just ask and someone will help you.

These saws are a beautiful piece of solid engineering and will just keep on running and being abused for years without a hickup, and are one of my favourites

 

[Simondo]

You have a phenomenal grasp for the obvious...which eludes me at times...thanks Simondo.

I really was not trying to be flippant with what i put over a clean down. "Obvious"...maybe, but just looking at the pics you put and where you were with the saw i figured it might be worth mentioning regarding saving yourself issues later on.

 

[CrystalRiver1]

I really was not trying to be flippant with what i put over a clean down. "Obvious"...maybe, but just looking at the pics you put and where you were with the saw i figured it might be worth mentioning regarding saving yourself issues later on.

I didn't take it as such...just merely stating the "Obvious"...I have a propensity to rush at times...again thanks.

 

[CrystalRiver1]

If I know I'm going to do a full strip, I remove the carb, coil and muffler, stuff something into the ports to stop any lumps getting in then give it a few rounds of degreaser and hose pipe.

When you're doing the strip (once it's clean) separate the case from the handle via the 4 AV mounts, intake boot loosened and slid away from the jug and impulse Line removed.

Things I'd always do on a saw of this caliber are:

- caber piston rings
-genuine crank seals
-genuine impulse line
-genuine fuel line and pickup
-Cylinder base gasket delete and replaced with yamabond etc - I like to apply a constant thin line of it around the base with a syringe and a fat needle, makes things a damn sight less messy.

Check the crank bearings once it's stripped down for play, a tiny bit of side to side play is okay but they should be tight up and down, and with the seals removed should spin nice and free with no resistance or lumpiness.

The carb may be alright, but always best to strip it and replace the gaskets and diaphragm - it'll be wearing a bing carb and the kits are available on eBay.

Don't want to step on anyone's toes or teach anyone how to suck eggs, but there's a wealth of information on here so if there's anything you need just ask and someone will help you.

These saws are a beautiful piece of solid engineering and will just keep on running and being abused for years without a hickup, and are one of my favourites

BRAVO MATE!
A definitive plan of action I can follow.
Thanks kind sir!

 

[jb-chainsaws]

BRAVO MATE!
A definitive plan of action I can follow.
Thanks kind sir!

No problem, anything else just give me a shout. I've got one of these on my bench this weekend too