by bgsengine » Mon Aug 07, 2017 6:54 pm
First, if it is homeowner use, that is still under warranty if it is an ignition or defect issue. However it sounds to me like you have a fuel wuality issue 90 pSI compression is much too low - I would suspect stuck piston rings from excessive carbon due to poor quality mix oil or stale gas. Seals would not cause your issue. Plug - make sure it is an NGK BPMR8Y or BPM8Y which is the only one that will work correctly in those machines - champion equivalents do not work well in them. Second, it could be failing ignition module (unlikely but possible) does it kick back on the recoil when it "pops" through carburetor? it could well be "stuck" in advanced timing, though also unlikely, and only way to check that is at a dealer with the PET4000 ignition analyzer - but ignition module failure would be under warranty (lifetime on the module) if you don't mess with it further - I would check if the owner has registered the machine as homeowner use and if so, it is still under warranty, so I would suggest taking it straight to the dealer
However as you have already been "tinkering" with it , technically it voids the warranty - dealer may or may not take it in for warranty inspection...
How poor are they who have not patience. What wound did ever heal, but by degrees? - Iago (Othello Act II, Scene 3)