# Tepramental and Idiosyncratic Chain saw @GRRRRR.com



## cathead (Jun 2, 2020)

I have this older Stihl 028 WB chain saw that has points ignition.  It has been running poorly and it surely is an ignition
problem.  Also, I have cleaned any oxidation visible under the coil and points with no success.  It runs but misses erratically
at any engine speed.  I have replaced the spark plug, the capacitor, and the ignition coil and the same malady lingers on.  
I have had the flywheel off a dozen or more times using my home made flywheel puller so finally set it aside and decided to 
vent on Hobby Machinist.  

On a different note, more along the lines of machining I am including a photo of the flywheel puller I made for Stihl saws.  
It was a while ago that I made it and I remember the the threads on the flywheel are metric and my lathe does not do
metric threads.  I used the closest thread pitch to the metric threads and the flywheel tool threads on about two turns before
binding.  Fortunately it has enough thread purchase to pop the flywheel off.   



It's a fun and somewhat challenging project if a person has a need for such a tool.


While I was at it I took a photo of the saw and the parts I have replaced.  It's been a good saw but this has me somewhat perplexed.  
I'm gonna sleep on it and give it another go in the morning.  One thing I did notice is that the key for the flywheel doesn't stick out
much on the crank, leading me to believe that possibly the flywheel is moving back and forth a little on the crank.  I have another
parts saw so will look through my parts and see if I have a spare key.  Other than that, there isn't much left.  I have cleaned the points and adjusted them so pretty much have ruled out the possibility that the points are faulty.  



The newer Stihl 028 saws have pointless ignition systems, apparently some sort of CDI "capacitive discharge ignition" and there are
aftermarket CD chips to replace points setups too.  I have tried those and the ones I had worked a while and eventually failed completely. 
 I'm open to any ideas anyone might have concerning this perplexity....


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## Martin W (Jun 2, 2020)

Are you sure it’s ignition issues? Cracked fuel line will cause the same miss and loss of power.
just trying to help.
Cheers
Martin


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## Ulma Doctor (Jun 2, 2020)

a hole in a carb diaphragm will cause poor performance


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## Capt45 (Jun 2, 2020)

My 028 WB is about 25 years old and still cuts great.  A while back I did have to replace the gas lines because of performance issues and she's good as she can be.


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## BtoVin83 (Jun 2, 2020)

My Poulon would run good with a full tank but as the level dropped a crack in the fuel line was available to air inclusion and= crappy run. New fuel lines and runs as good as it ever did, notice I didn't say it ran great because it is a poor excuse of a chain saw but was free so what the heck.


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## cathead (Jun 2, 2020)

Thanks for all the responses.  I'm pretty sure it is spark related but will look at the fuel lines and carb as well to 
get to the bottom of it.  Apparently the newer saws have a CDI built right into the coil because it looks like just
a coil and flywheel magnet.  The CDI must be hidden in the coil apparently...   I have other saws but it would
be nice to have this one running right.


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## Aukai (Jun 2, 2020)

Do you have a magnet under the flywheel for the ignition?


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## Ulma Doctor (Jun 3, 2020)

Totally unrelated saw
I just repaired a homelite saw from the 80’s
It had an early prestolite CDI pointless coil that is heat sensitive 
Apparently if the saw is used out of normal position for long periods of time, could induce a miss-or stop spark altogether.
My dad gave me the saw 10years ago, it stopped running 2 years ago allofusudden.
I pulled it apart enough to pull the coil out.
I looked for upgrade coils and didn’t have much luck. I did find a site for a guy who loves the old homelites and he suggested baking the coil at 225*F for 20 minutes.
The coils insulation is somehow rejuvenated and it may restore operation.
I was a non-believer until I tried it.
Long story short, it runs like a top again


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## markba633csi (Jun 3, 2020)

I'm thinking fuel problem too- you could rig up a test light with a small fluorescent lamp and a bit of wire to ground to monitor the coil output while it's running- rule out electrical first
-Mark


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## Aukai (Jun 3, 2020)

When I worked on Mercury outboards, with a magnet was involved, and the magnet got weak it would cause a miss, also poor coil grounds....


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## cathead (Jun 3, 2020)

Aukai said:


> Do you have a magnet under the flywheel for the ignition?



The magnet is on the outer perimeter of the flywheel.


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## Downunder Bob (Jun 3, 2020)

I have 3 of those older Stihl machines, they range from about 30 to 45 years old. Each one has over the years given me problems, but they have rarely been ignition, almost always fuel, like pinhole in fuel pump diaphram, hard dry cracked fuel line, dirt in carby etc, but rarely ignition.


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## mmcmdl (Jun 3, 2020)

One word . Ethanol .


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## Chips O'Toole (Jun 3, 2020)

I have acres of trees that fall over every time a coon or squirrel breaks wind, and the weather here is hot and humid. Lots of chainsaw problems. I have learned two important things.

1. Never pay to have a carb fixed. Buy a new one on Ebay. If you have a relatively new chainsaw, the carb was probably made in a Chinese factory, and you can probably buy an identical carb for about $13, or roughly 25% of what the manufacturer will charge you for the same product. The new carb will probably come with other parts, such as a spark plug and maybe fuel lines and a fuel filter. It will be just as good as your original Chinese carb, and you will avoid paying someone $100 to keep your saw for 6 weeks and unblock your old carb. When you buy a new saw, you might as well buy a spare Chinese carb to go with it. Otherwise, you may be stuck without a saw while you wait for your new carb to show up.

2. Buy a big sonic cleaner. When you take your old carb off your saw and put a new one in, you will want to fix your old carb so you'll be ready when the new one clogs up. Open the carb up, put it in a sealed jar of gasoline, and put the jar in your sonic cleaner. It will knock the ethanol crud loose. By using a jar instead of filling your cleaner with solvent, you avoid burning your house down, you save money, and you don't make a mess. Just set the gas-filled jar down in the hot water.

Other good tips: don't use Sta-Bil. It doesn't work. I've been using a product called Biobor EB, and it's somewhat better. Use ethanol-free gas only. When you're done cutting for the day, empty your tank, run your saw dry, put a tiny amount of premixed fuel in it (the $20/gallon stuff), and run it dry again. This way you get the benefit of the high-end gas with very little of the financial pain. If that's too much work, never let a small engine sit more than a couple of weeks with fuel in it. Also, if you have one of those idiotic greenie gas cans that spill gas everywhere, go to Ebay and buy an old-fashioned spout for it. Better than pouring gas all over your saw and your yard or floor every time you fill it. You can also buy a vent which makes gas flow correctly. Buy spare diaphragms for your carbs, because most diaphragms are garbage.

It's amazing that the American public tolerates the destructive ethanol farce.


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## Buffalo21 (Jun 3, 2020)

mmcmdl said:


> One word . Ethanol .



in the gas or in the operator??


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## RJSakowski (Jun 3, 2020)

Another cause of poor performance on two cycle engines is a weak or broken reed valve.


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## mmcmdl (Jun 3, 2020)

Buffalo21 said:


> in the gas or in the operator??



Usually both .  All my saws run perfectly up in NY in the Adirondacks because I can buy un-ethanoled gas . I now run up to Pa. and fill up with the same . I've had no issues this year with things being messed up but my larger Stihls and Huskies have not been addressed as yet .


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## tghsmith (Jun 3, 2020)

check the ribbed fuel line in the tank,, mine had "softened" from age and fuel.. it would idle and run , but would "bog-out" under load as the fuel line collapsed on itself.. the muffler can also get clogged and is cleanable..


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## middle.road (Jun 3, 2020)

It's not just the ethanol.
I've got (5 or 6) 2-cycles sitting in the tractor shed that need attention so I figured I'd spend an evening watching videos on the matter.
2-cycles have never liked me to begin with.
I always see the 'premium' fuel at the estates sales, guess what I'm going to start grabbing when I can?

This was rather informative:


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## mmcmdl (Jun 3, 2020)

middle.road said:


> guess what I'm going to start grabbing when I can?



More motors ?  I have a garage full of things to get running again . 3 Honda 400 ex's , 3 expensive chainsaws , a couple of Echo straight shaft trimmers etc . I find I just buy new ones and these sit until I can get a round tuit . ( I think they sell them on the bay ) 









						A Round TUIT When you get a Round To It Qty (5)   | eBay
					

For those that need to Stick TUIT after they get a Round TUIT! ★Works great for employees and co workers too! They (or you) wont have any excuses when they have a Round TUIT to get things done! Get the kids or spouse to help out around the house.



					www.ebay.com


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## middle.road (Jun 3, 2020)

mmcmdl said:


> More motors ?  I have a garage full of things to get running again . 3 Honda 400 ex's , 3 expensive chainsaws , a couple of Echo straight shaft trimmers etc . I find I just buy new ones and these sit until I can get a round tuit . ( I think they sell them on the bay )
> 
> 
> 
> ...


I bought three dozen, but they got lost in my mess of a workbench(es) as soon as I unpacked them.


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## Barncat (Jun 3, 2020)

The flywheel key shouldn’t matter much. I have built saws without them so that I can advance the timing, the clean taper holds the flywheel in position. If it can only move a little, it will simply advance or retard timing by a degree or two.


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## matthewsx (Jun 3, 2020)

Many difficult to diagnose issues with 2 cycle engines stem from leaks on the lower end, specifically crank seals leaking.

I don't know if this is your issue but when you have exhausted all fuel and ignition areas of troubleshooting, crank seals, or a leaking crankcase is often the problem. It's relatively hard to verify since you need to build intake and exhaust blanks and do a leak down test of the whole engine. One quick check is if you can squirt a little carb cleaner right at the crank seal in question while the engine is running and it revs That's pretty much a give away but it can be hard to do.

John


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## Downunder Bob (Jun 4, 2020)

Buffalo21 said:


> in the gas or in the operator??




Both.


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## Downunder Bob (Jun 4, 2020)

RJSakowski said:


> Another cause of poor performance on two cycle engines is a weak or broken reed valve.


Not had this problem.


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## cathead (Jun 4, 2020)

I'm wondering if anyone here had disassembled a Stihl 028 WB.  Does it have a reed valve?


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## Liljoebrshooter (Jun 4, 2020)

Almost all of these engines are piston ported and don't have reed valves.

Joe


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## RJSakowski (Jun 4, 2020)

My old Homelite saws both had reed valves.  The reed stress cracked on the Homelite XL, causing poor performance.  However, looking at a parts diagram for the Stihl 028, it doesn't appear to have a reed valve.


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## ELHEAD (Jun 5, 2020)

matthewsx said:


> Many difficult to diagnose issues with 2 cycle engines stem from leaks on the lower end, specifically crank seals leaking.


After replacing all electronics , first with used parts, then with new replacement parts on my 1982 Husky 266, I took my saw to a friend . Even though an amateur he diagnosed it as a leaky cank seal. It still is one of the best gas powered tools I have owned.
Face


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## tghsmith (Jun 6, 2020)

having worked on hundreds of 2 cycle engines most electrical problems are normally fuel problems,, I do have a 028WB that I bought new in the late 80's, it has always been my go to saw,, over the years I rebuilt the carb once, cleaned the muffler twice, replaced the fuel tank internals,, always start a repair checking things from the outside inward,, the saw is on its second bar and sits at the ready for fast service.. always try to use alcohol free fuel, don't leave fuel in the tank for extended periods..  I live in a wooded neighborhood of large lots,, always figure I'll be one of the people clearing the path to the main road after a bad weather event,  two hurricanes and one major ice storm so far  ,PS the brass strip contact switch was not the best design, I replaced mine once and keep a spare in the case..


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## mariner3302 (Jun 6, 2020)

I have an old Craftsman 18" chainsaw that runs like a raped ape IF you get it to start in the 2nd or 3rd try after the initial attempt. To do that, on mine, you have to do the choke pull, choke pull, no choke pull, then trigger. Once you get past that and it still hasn't caught, you might as well put it back on the shelf because you are done with it for at least half a day! I bought a Lowes branded job a couple years ago. Spring vibration isolators, short stroke starter, easy to start... I love it but I can't bring myself to get rid of the old cantankerous Craftsman. Kind of the same as the pretty truck and the old beater that gets the job done in conditions that you would hate yourself for taking the pretty one.


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## cathead (Jun 8, 2020)

On most saws, it works best to put on the choke and pull the engine over till it fires.  At that point,
the engine is essentially flooded.  Then setting the engine to "run" and pulling it over leans the
mixture and allows it to start.  The start process usually will require three to four pulls to start. 
This is of course regarding a cold engine.  Once warm, one pull will usually suffice.


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## SLK001 (Jun 8, 2020)

I had a 4-stroke trimmer that had a failed primer bulb yesterday.  Taking the trimmer apart enough to access the bulb, one of the fuel lines "disintegrated".  I had some 5/32 fuel line that was "almost the same", so I hooked it up and managed to squeeze one end into the tank.  The fix completed, I reassembled and fired it up.  It ran like **** to say the least.  I figured that the new fuel line I used was closed off entering the hole in the tank, so I opened up the hole enough for an easier fit for my new line to allow air (or gas?) to pass back into the tank.  After reassembling and start up, the engine now runs with full power.

Just my latest foray into small engine repair.


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## Twirpunky (Jun 8, 2020)

I had a 25 year old Husqvarna. Worked great for all those years. Started acting up, missing, quiting, all the same problems.  Figured I would start with gas line. Then to carb mount seal. Then to carb kit. Then to new carb. Then to ingition coil. Got it down to crank shaft seals. Took it all the way down to the crank. Ordered the seals.  The wrong seals showed up after two weeks waiting. 

   Threw the whole works in the trash and bought a new saw. Runs great!!!!

  What did I learn. I am bull headed!! 

Use the saw for 20 years and buy a new one once it starts giving you troubles.  After 20 years, I deserved a new saw.

D


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## Buffalo21 (Jun 8, 2020)

I have 4 chainsaws, a Stihl, 2 Husqvarnas and a 25-30 yr old Jonsered (which still runs the best).


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## SLK001 (Jun 8, 2020)

Twirpunky said:


> I had a 25 year old Husqvarna. Worked great for all those years. Started acting up, missing, quiting, all the same problems.  Figured I would start with gas line. Then to carb mount seal. Then to carb kit. Then to new carb. Then to ingition coil. Got it down to crank shaft seals. Took it all the way down to the crank. Ordered the seals.  The wrong seals showed up after two weeks waiting.



All that failure would have had me questioning my man-hood - or at least my engine repairing ability!


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## Twirpunky (Jun 8, 2020)

Save your manhood. Even if it runs good, buy a new saw every 15 years and throw the old one out. Don't give it to a buddy, he will want you to fix the dang thing.  "THROW IT OUT"

Oh, another thing.  Throw it out on the same day as the garbage truck picks up the trash. If you are like me, you will be picking it out of the trash for another attempt at fixing it. 

D


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