bwringer
Well-known member
Yep and yep. One day we'll look back on all this stinky unreliable gas-powered **** and just laaaaaaaugh...
Repairing Stihl Backpack Blower
- Thread starter GarageDan
- Start date
Yep and yep. One day we'll look back on all this stinky unreliable gas-powered **** and just laaaaaaaugh...
Bretny
Well-known member
I got a new carb for a stihl 026 chainsaw a few years ago. Spent about $13. Just last week i needed a carb for a 15hp kohler with electrical shutoff. $18 shipped. Its hardly worth doing more than taking the bowl off and shooting it with cleaner.
Haven't you heard. The pleasure derived from spending a day at the workbench fixing something adds an extra day to your life.
oldmxracer
Well-known member
Yes it is VERY possible ! There will be fuel left in the bottom end of the engine also.
Just had it happen to Me this year on My old BR400 (I SCREWED UP BIG TIME ON STARTING) and continuing to get it started.
removed the muffler and drained, while it was off laid the unit on it's side with plug removed ( do not let spark get close) pulled the hell out of it wide open which got the gas out of the bottom end !
Put it back together throttle wide open and pulled till it started runs and cleans it's self out .
spudley
Well-known member
Thanks for the tip. I'll give it a try Friday.
You kid, but I honestly find fiddling with things on the work bench very relaxing. It's a hullava lot more fun that doing the yard work. :lol
I'm leaning in that direction...
I couldn't sleep so I went out to the shop. I cleaned the frame underneath the motor and tank and down the exhaust side of the motor. What a mess.
I checked the diaphragm again. That little disc is metal so it should be rigid, however it all is and shouldn't be. All the black rubber should be as soft as silk from what I've researched. That's definitely an issue.
I emptied the tank and checked it out. I appears good and clean and doesn't appear to be leaking.
I reassembled the air filter housing, carb, pull starter etc. Basically everything except the muffler and plastic cover.
I pulled the plug and I checked the compression on the cylinder three times: 75, 80, 80. I would think that's good compression. Before checking the compression I laid it down and pulled it a bunch and no gas or anything came out any holes. If it was overly flooded, it's good now.
When it warms up I'll put some fresh gas in and try to crank it (no choke) without the muffler and see what happens.
I checked the diaphragm again. That little disc is metal so it should be rigid, however it all is and shouldn't be. All the black rubber should be as soft as silk from what I've researched. That's definitely an issue.
I emptied the tank and checked it out. I appears good and clean and doesn't appear to be leaking.
I reassembled the air filter housing, carb, pull starter etc. Basically everything except the muffler and plastic cover.
I pulled the plug and I checked the compression on the cylinder three times: 75, 80, 80. I would think that's good compression. Before checking the compression I laid it down and pulled it a bunch and no gas or anything came out any holes. If it was overly flooded, it's good now.
When it warms up I'll put some fresh gas in and try to crank it (no choke) without the muffler and see what happens.
chaosracing
Well-known member
Yes the disc is metal, but the rest of it is supposed to be flat and flexible. You will find that a rebuild kit is the same cost or more for these carbs. Do yourself a favor. Dont waste your time trying to start it until you get a new carb. Not worth the headache and time. It wont start with the diaphragm like that. It also means the other rubber components of the carb are shat as well.
Bretny
Well-known member
Check your compression gauge and make sure the decomp valve isnt open. Thats not good compression. It may be so low that the engine wont run. What do the rings and cyl look like peeking into the exhaust?
Drip a few dribbles of oil in there and do the test again.
Drip a few dribbles of oil in there and do the test again.
mjeff87
Well-known member
I'm going to go in a completely different direction on this and say check the flywheel key to see if it's sheared off and has jumped timing. I fixed a coworkers Stihl, same model, and that was the problem. Muffler was about half full of 2 stroke mix from trying to repeatedly start it without getting the spark at the right time, just like yours.
Put it all back together and see if it runs after what you did. If it still doesn't, give it a TINY spray of starting fluid and see if it fires off. If it doesn't, I'd say you have an ignition problem. You can check for spark and you'll likely see a good healthy spark, problem is it's not in time. To get to the key you pretty much have to completely disassemble the whole unit to get to the flywheel. Stihl makes a flywheel puller ($$$), but you can pop it off with a punch and hammer, carefully.
Put it all back together and see if it runs after what you did. If it still doesn't, give it a TINY spray of starting fluid and see if it fires off. If it doesn't, I'd say you have an ignition problem. You can check for spark and you'll likely see a good healthy spark, problem is it's not in time. To get to the key you pretty much have to completely disassemble the whole unit to get to the flywheel. Stihl makes a flywheel puller ($$$), but you can pop it off with a punch and hammer, carefully.
gemniii
Well-known member
On my saws that would be very low compression.
Have not tested my blowers.
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That's terrible compression. It varies, but you usually need 110-120 as a min.
Your compression guage could be bad. Is it designed for 2 cycle engines and does it have a schrader valve right at the spark plug/cylinder fitting? If it's the old type that you hold a rubber ****** against the spark plug opening then they are usually inaccurate for small 2 cycle engines.
Any chance that blower was ever straight gassed? Is it old with heavy use? If not I think your compression readings are erroneous.
Your diaphram is bad if it's stiff. Just replace the carb./filter/fuel lines and report back.
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chaosracing
Well-known member
Found this info on another forum, not my words, but someone else.
Any two stroke, 125psi, is close to worn out, 150psi is a decent used machine, 175psi is a good running machine. Anything less than 125 on a two stroke, it's toast and hard to start.
Any two stroke, 125psi, is close to worn out, 150psi is a decent used machine, 175psi is a good running machine. Anything less than 125 on a two stroke, it's toast and hard to start.
