AboutJohn C. Bridgers Sr. Expertise Small Engine Service Center Co-Owner - ATVs, Mowers, Trimmers, Snow throwers, and Many Other Small Engine Operated Equipment. I can answer questions pertaining to Most Lawn and Garden Equipment, e.g. riders, tillers, trimmers, cement mixers, chainsaws, etc. I have been repairing small engines for 34 years. Briggs & Stratton, Tecumseh, Kohler, Lawn Boy, Stihl, Poulan, Mac, and Honda; to name a few.
Experience
Past/Present clients I have worked on small air/water cooled engines for 34 Years. I performed warranty work for Lowes of Wilson and other retailers in the area. I Own a Yard Maintenance and Certified Small Engine Repair Service Center.
The exhaust port and muffler are very clean for a 15 year old saw. The compression when cold was about 90 on the first pull and went up to 150 after 2 more pulls. I ran the saw for a minute or so (it stalled and would not start again). The compression fell to 60 on the first pull then went to 120 after 2 more pulls. There is still fire to the plug when this happens, but I suspect you are right with the coil/ignition module diagnosis as I have had a similar problem with a motorcycle - bike starts then dies after a minute or so. Put the box in the freezer for a bit and the bike starts again.
Thanks,
Kevin
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The text above is a follow-up to ...
-----Question-----
John,
I have a Craftsman chainsaw that has worked fine for 15 years. Recently after about 10 minutes of cutting the engine died and was very hard to start. When it started it ran for a couple of seconds then died. It seems like it was starving for fuel. I cleaned the carb and changed the plug. Started OK then died after a few minutes of cuttng. Same symptom again on restart, appears to be starving for fuel. Checked all venting and filters and they are fine. A friend suggested that these are the sysmptoms of a worn out 2 stroke and that it was time for a new saw. Could this be the problem?
Thanks,
Kevin
-----Answer-----
Hello Kevin:
By Checked all Venting, I Assume you Checked the Exhaust Port and Muffler. If this is True, then Check the Compression When the Unit Stalls. If Less than 70psi, then the Engine needs Rings. Does the Saw have Fire to the Plug when this Happens? This is Usually a Sign that the Coil/Ignition Module is Bad. Your Description Describes a Bad Coil/Ignition Module. Usually Bad Rings will Not Allow the Engine to Start even when the Engine is Cool. Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. Thanks. Be Safe.
Good Luck
Respectfully
John
Answer Hello Kevin:
The Drop in Compression is Not Unusal as Long as on the Second or Third Pull the Compression Goes Back Up to Above 90psi. Pour a Small Amount of Marvil Mystery Oil Into the Cylinder and Let it Set Overnight. Then Clean Out the Oil. The Mystery Oil will Help Loosen the Rings if they have Rusted to the Piston and Aren't Flexing Properly. Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. Thanks. Be Safe.
Good Luck
Respectfully
John
Hello Kevin:
I forgot to tell you to Make Sure the Piston is Above the Exhaust Port before Pouring in the Mystery Oil. Thanks.
