I guess you have a 10684 or 10683 'Insight'? The first thing to check is the mulch plate or bag installation. The heavy wire extension must be all the way down in the RH retaining slot on top of the discharge box. There should be no debris in the channel under the frame. Make sure the piece is snugged all the way down, because there is a magnetic switch under it which cuts off the ignition to prevent starting/running without anything covering the discharge port. If that's not it, look at the switch wire connection at the engine brake (the part that moves when you operate the engine/blade control bail). If that is a good, tight connection with no corrosion, it's probably okay. Now you'll have to remove the tank shroud and steel air shroud to get to the coil and flywheel. It has been reported that the magnet on the flywheel on a very few units has come loose, killing any magneto effect. Plus, you'll need to do this anyway to replace the CD pack (coil).

While a plugged muffler or plugged exhaust ports will keep a LB from running right, it will not keep it from at least firing a few shots. Engine couldn't possibly have run to that point. Cleaning the muffler depends on WHAT muffler your LB has. The one pc. steel ones can be thrown in your charcoal grill when you have finished cooking and left. Tap/blow out when cooled. The muffler for the model number given is a 2 pc. cast aluminum one which easily comes apart for cleaning. Use some SeaFoam in your fuel for a few tanks full. Your trouble could be a lot of things. That model is the first one with CDI which continues to be a weak spot with LB. However, you say you have good spark so shouldn't be that. Could be bad crankcase seals or bad reed valves. Walt Conner

I also have the 3650 and it does one heck of a job....love it. I've used it 3 times already this winter. Like others said it cleans right down to the concrete...that was why I chose it over the 2 stage. I bought mine from Speedway Sales (great price no tax-free ship). I was on there site yesterday and the 3650 was sold out....that tells me something. I also noticed Toro has a new model somewhat like the Commander but has same 6 1/2 Duraforce as the 3650 but don't know much about it. I think the 3650 is made to handle up to about 12" of snow but I have gone threw 18" drifts taking a couple bites. Some complain about the 2 cycle oil smell...but this season I switched to synthetic 2cycle oil and don't get the smell and it seems to run better. I now use synthetic 2 cycle in my string trimmer , leaf blower and now the 3650 also.

Orange : Not Stubborn at all just knowledgeable within Proper Oil Specifications. You have 13 LB which run ok on Marine Grade Oil then that's all that matters to you . I have run Snowmobiles , Snow-blowers , Chainsaws , Motorcycles , Outboards and Inboards and frequently upgrade my Oil Specifications accordingly to the Best (Better than Suggest Manufacturer Grade). I also repair and rebuilt the above for numerous friends and clients for over 30 yrs. I guess that's why have Chainsaws and Lawnmowers and Snow-blowers that never quit due to improper maintenance or inferior lubrication , because I have seen the results 1st hand.I further understand that the TC-W3 Specs which are Administrated from the NMMA have been recently amended , however that has do with the reduction in dispersant additive within the oil for anti fouling due to moisture intrusion from thermal cycles or leaking seals . It had nothing to due with the adding a detergent to Reduce Carbon which is a Proponent your Marine grade oil will not provide your air-cooled unit. Any amount of carbon 0.40 fouling on a Piston Dome can cause rapid failure . This is why Old Mineral oils required routine Engine Top End De-carbonizing back in the Day . As I said I don't Rely on a Manufacturer who wishs for eventual unit replacement to Guide my Oil Selection . The Oil I use is a little more expensive but I feel it's warranted do to the Application of Use and the Additives Required. You have a right to your opinion but I would suggest you review the Most Recent Oil Specifications Guide on Marine vs Air-Cooled Engine Recommendations and Not Minimum Standards of one Manufacturer . Anyhow Good Luck with your Lawnmowers Bro ! I enjoyed the discussion :)