I have a 10 year old Lawn Boy Gold Pro DuraForce 6.5HP 2 stroke walk behind mower. Over the last 2 years it has become increasingly difficult to start when cold. This thing formerly was a one pull start. Now it takes 10-20 minutes. I crank on it a while, then prime, then crank, and repeat that cycle for a few minutes. The only way I can start it lately is to apply a heat gun to the head for 5 minutes. It will usually pop right off after that but not every time. After it starts it runs fine. Always has run well.
The spark plug is new and does create a spark that I can see when the plug is unscrewed and placed in contact with the motor. The gas is less than 2 months old. Priming button is new.
Additionally, the motor is very hard to start after a 5 minute pause when hot.
A wise boat motor mechanic once taught me that you need 3 things for an engine to run: gas, air, and spark. I'm not sure what is causing these problems and I want to be able to figure this one out with your help. I don't want to take it to a shop as I'm afraid it will cost me as much as a new mower to fix it.
He forgot one thing...maybe more....
Breathing
Even a four stroke needs this....and suffers without it...
Ever back an automoble into a snow bank ?
And yet another task for me, as a clogged exhaust causes a drop in performance.
I replaced the coil and, behold, it started on the first pull.
It still has a hard time with hot starts if it sits any more than 2 or 3 minutes. I'll have to try cleaning the exhaust port first. If that's not it then maybe it is a carb issue?
I've learned something new in this thread: that a small engine can run (poorly and hard to start, mind you) with a bad coil. Does anybody know when this two-stage coil was introduced or on which models/engines it was installed?
