max power Posted July 15, 2013 Report Share Posted July 15, 2013 I have an old McCullouch Timber Bear. It has always run well until recently. It has become a bitch to start.I have to pull the plug and dry it every time. Then usually hit it with starting fluid. Once it's running, it runs fine and strong, idles well and all, but if you shut it off, it won't start again. I pulled the plug and cleaned it. It was wet with gas, but it didn't spray out of the plug hole when I cranked it sans plug. I pulled the carb and checked it. Clean and unclogged. The fuel line is new, full of fuel and its getting good spark. Not sure what to make of it. Thoughts? Quote Link to comment Share on other sites More sharing options...
grapesmuggler27 Posted July 16, 2013 Report Share Posted July 16, 2013 Flux capacitor 1 Quote Link to comment Share on other sites More sharing options...
vf1000ride Posted July 16, 2013 Report Share Posted July 16, 2013 Most likely needs the Carb rebuilt. There is a small checkvalve that prevents fuel from leaking past the Carb when the engine is off. It's most likely leaking and flooding the engine when turned off. Does the primer bulb go dry when the engine is off? That is usually the easiest external sign of the internal leak. 1 Quote Link to comment Share on other sites More sharing options...
RCBS Posted July 16, 2013 Report Share Posted July 16, 2013 Low compression, or possibly sucking air (crank case seal or intake boot). Leaning more towards low comp. Do you use quality mix and fuel? Ethanol is hard on small engines. May have been running lean due to crud in carburetor or plugged fuel filter. How often do you change the fuel filter? Quote Link to comment Share on other sites More sharing options...
max power Posted July 16, 2013 Author Report Share Posted July 16, 2013 No bulb, no fuel filter. Old skool! Early 90's model. I did the finger-in-the-hole compression test and it seems to have good compression. Rebuilt the carb 3 years ago and have maybe 3 or 4 hours on it since. Not that that means anything. Quote Link to comment Share on other sites More sharing options...
RCBS Posted July 16, 2013 Report Share Posted July 16, 2013 Most likely needs the Carb rebuilt. There is a small checkvalve that prevents fuel from leaking past the Carb when the engine is off. It's most likely leaking and flooding the engine when turned off. Does the primer bulb go dry when the engine is off? That is usually the easiest external sign of the internal leak. This also. Check fuel line. My '97 husky had a cracked fuel line where it exits the tank once. Quote Link to comment Share on other sites More sharing options...
max power Posted July 16, 2013 Author Report Share Posted July 16, 2013 Fuel line is brand new and holding fuel. Quote Link to comment Share on other sites More sharing options...
RCBS Posted July 16, 2013 Report Share Posted July 16, 2013 No bulb, no fuel filter. Old skool! Early 90's model. I did the finger-in-the-hole compression test and it seems to have good compression. Rebuilt the carb 3 years ago and have maybe 3 or 4 hours on it since. Not that that means anything. Junk fuel. Gasoline goes to shit in a hurry nowadays. If a carburetor isn't too expensive, i'd toss one on it. Engine should have at least 100psi comp. Quote Link to comment Share on other sites More sharing options...
max power Posted July 16, 2013 Author Report Share Posted July 16, 2013 Just tried the spark test again and it doesn't appear I'm getting good spark. Hopefully it's just the plug, but that doesn't make sense to me since it runs and idles fine once it starts. Quote Link to comment Share on other sites More sharing options...
max power Posted July 16, 2013 Author Report Share Posted July 16, 2013 160 psi compression. Quote Link to comment Share on other sites More sharing options...
RCBS Posted July 16, 2013 Report Share Posted July 16, 2013 Just tried the spark test again and it doesn't appear I'm getting good spark. Hopefully it's just the plug, but that doesn't make sense to me since it runs and idles fine once it starts. Coil could have been slowly dying. Especially if it is worse? when the saw is hot. Sparkplug cheapest place to start. For the love of Odin, put a filter on it! Mower or saw shop should have a buzzbox to test coil. Quote Link to comment Share on other sites More sharing options...
max power Posted July 16, 2013 Author Report Share Posted July 16, 2013 (edited) I'm not even sure where the coil is on this pig. Looks like it's time to tear the thing down....again.Thanks for you help Edited July 16, 2013 by max power Quote Link to comment Share on other sites More sharing options...
max power Posted July 16, 2013 Author Report Share Posted July 16, 2013 Here's another weird issue. If you let it sit for a bit, it will start and run...until you shut it off and try to restart it. Perplexing. 1 Quote Link to comment Share on other sites More sharing options...
chevysoldier Posted July 16, 2013 Report Share Posted July 16, 2013 Run some sea foam through it. Quote Link to comment Share on other sites More sharing options...
JohnG Posted July 16, 2013 Report Share Posted July 16, 2013 Rebuilt the carb 3 years ago and have maybe 3 or 4 hours on it since. Not that that means anything. Hate to say this, but I'd tear it apart and re-check your work. Also, give a good look at the intake valve... out loud I'm thinking "saw gets hot, intake valve sticks, allows too much fuel in and floods the plug when you try to restart. Taking the plug out and drying allows engine time to cool down and valve stops sticking." Just a thought. Thank goodness it's not a Pull-on... Quote Link to comment Share on other sites More sharing options...
max power Posted July 16, 2013 Author Report Share Posted July 16, 2013 Hate to say this, but I'd tear it apart and re-check your work. Also, give a good look at the intake valve... out loud I'm thinking "saw gets hot, intake valve sticks, allows too much fuel in and floods the plug when you try to restart. Taking the plug out and drying allows engine time to cool down and valve stops sticking." Just a thought. Thank goodness it's not a Pull-on... The carb is pretty easy to disassemble at this point. Ill give it a check tomorrow. I think my issue is more to do with weak spark, though Ive been wrong before, hence this thread. If I hadnt just invested in a new Stihl weedeater, Id craigslist this old beast and get a new Stihl saw. Quote Link to comment Share on other sites More sharing options...
vf1000ride Posted July 16, 2013 Report Share Posted July 16, 2013 give a good look at the intake valve... out loud I'm thinking "saw gets hot, intake valve sticks, allows too much fuel in and floods the plug when you try to restart. Taking the plug out and drying allows engine time to cool down and valve stops sticking." Huh? Intake valve? This is a 90's chain saw, there is no 4-stroke here. Better fix that to be a reed valve. Quote Link to comment Share on other sites More sharing options...
oldschoolsdime92 Posted July 16, 2013 Report Share Posted July 16, 2013 Here's another weird issue. If you let it sit for a bit, it will start and run...until you shut it off and try to restart it. Perplexing.Coil or carb. I've had saws run fine until they get hot and Once they cool down, good to go again. Coil fixed them. Quote Link to comment Share on other sites More sharing options...
20thGix Posted July 16, 2013 Report Share Posted July 16, 2013 Grab the handle of the pull cord and pull it until its all the way extended. Once out all the way, use your other hand to make sure you have a firm grip on the handle. Next violently swing it around in a circle above your head. When your at maximum speed release it off a bridge. On its way down yell " Fuck you , you piece of shit!". Get back in you car and go buy a new one. I did something similar to that with my pressure washer wand over the weekend but shucked it into the trees out of anger.. Seems that everytime i let someone borrow it, it comes back broke. Going on wand number 3 now. It shall never be loaned out again. Quote Link to comment Share on other sites More sharing options...
max power Posted July 16, 2013 Author Report Share Posted July 16, 2013 If i were to put it on the replacement list, it would sit firmly behind the compressor that is dying a slow death and the gas grill that is rusting out and the repair on the wife's truck that is pumping oil into the air cleaner all of a sudden. In other words, it's a good old saw that just needs repaired, and quick. I gots free firewood to go collect. Quote Link to comment Share on other sites More sharing options...
JohnG Posted July 16, 2013 Report Share Posted July 16, 2013 Huh? Intake valve? This is a 90's chain saw, there is no 4-stroke here. Better fix that to be a reed valve. Lol. No Shit, Need To Read Before I Hit Post. Shouldn't Get On Here WhenI 've Been Hitting The Jamesons Quote Link to comment Share on other sites More sharing options...
grapesmuggler27 Posted July 16, 2013 Report Share Posted July 16, 2013 Jamisons....you mean coffee sweetner Quote Link to comment Share on other sites More sharing options...
max power Posted July 17, 2013 Author Report Share Posted July 17, 2013 Well....I looked up the plug gap, found it to be a little narrow, and re-gapped. IT LIVES!!! Hopefully that was all it is, but we shall see. It definitely runs at higher RPMs now as opposed to yesterday. I don't fully trust it yet as it ran before, but it does start after being run now and is t nearly as hard to start. Quote Link to comment Share on other sites More sharing options...
max power Posted July 17, 2013 Author Report Share Posted July 17, 2013 I spoke too soon. Fucker won't start now. FUCK!!! Quote Link to comment Share on other sites More sharing options...
oldschoolsdime92 Posted July 18, 2013 Report Share Posted July 18, 2013 Grab the handle of the pull cord and pull it until its all the way extended. Once out all the way, use your other hand to make sure you have a firm grip on the handle. Next violently swing it around in a circle above your head. When your at maximum speed release it off a bridge. On its way down yell " Fuck you , you piece of shit!". Get back in you car and go buy a new one. I did something similar to that with my pressure washer wand over the weekend but shucked it into the trees out of anger.. Seems that everytime i let someone borrow it, it comes back broke. Going on wand number 3 now. It shall never be loaned out again.I know how that goes, all too well! Quote Link to comment Share on other sites More sharing options...
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