QuestionQUESTION: I have a Sear 18" 42CC chain saw. It was working and just stopped. These are
the following things I have
done:
1. Checked for spark - Have a good spark
2. Fuel is going into the Carb.
3. Cleaned Carb
4. Adjusted the idle, high & low screws.
5. Checked the muffler system - clean
6. Cleaned the magnet surfaces
7. Sprayed started fluid in the carb & attempted to start. Doesn't even burb
8. Check compression - fine
So it has good fuel, good spark I'm stumped.
Any suggestions?
Thanks
Phil
ANSWER: Hello Phil:
Sorry for the Delay. High Winds have Downed Trees and my Electric is Out and the Darn Generator Coil went Bad. lol Its been a Fun Past 2 Days. If you have Good Compression, Fuel, Clean Exhaust and the Plug is Firing, then Check the Flywheel Key. The Flywheel Key Times the Plug Firing with the Cylinder Position During the Power Stroke. If the Key is Damaged the Plug Fires at the Wrong Time and the Engine Does Not Start or Run. To View a Breakdown of this Unit Go to this Site Addy, http://www3.sears.com/ and Enter the Model Numbers in the Upper Left Search Box and Click Go. Then Visually Verify the Equipment and Click Continue. From this Page you can View Diagrams or Parts Lists for you Equipment. If you Hit a Snag or this Does Not Correct the Problem, I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Thanks.
Good Luck
Respectfully
John
PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Thanks.
Respectfully
John
---------- FOLLOW-UP ----------
QUESTION: John,
Thanks for answering my question. Check everything you stated. The flywheel
key is fine. I guess the only thing left is the compression. We have a
compression gauge and checked It read 65. We took another chain saw with
aprox the same cc and the compression was much higher.
What do you think, is the compression to low for a spark and if so should I
just buy a new chain saw?
Thanks,
Phil
www.powerwashofva.com
AnswerHi Phil:
Chainsaw Compression is Usually 100psi to 110psi or Better. Some will Show 90psi and Still Run and Cut Good. 65psi is Not Enough Compression for the Engine to Run. Usually Any PSI Below 80psi will Cause Idling and Power Problems. If the Compression is Below 70psi, an Engine will Not Usually even Start. When you had the Muffler Off; What Did the Piston and Cylinder/Jug Look Like? Was the Cylinder/Jug and Piston Sides Smooth like Glass or Rough like Sandpaper? Was there Any Gouges in the Cylinder or Piston Walls? I Suggest you Purchase a New Saw and when you have the Time Research this Saw and Make the Repairs. Even if you have to Replace the Rings, You will have a Backup Saw for Less than $100.00 if the Cylinder/Jug and Piston are Not Damaged. If you Hit a Snag or this Does Not Correct the Problem, I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Thanks.
Good Luck
Respectfully
John
PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Thanks.
Respectfully
John
