OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines Intek 5.5HP backfires on (not) starting

The Intek 120000 engines have a Walbro LMS carburetor, and these have a dry primer system, unlike the wet primer found in the PulsaPrime carburetors. As I understand it, the LMS primer bulb pumps air into the float bowl vent. This pressurises the float bowl, forcing fuel through the main jet and the discharge nozzle at the top of the emulsifer, into the venturi. So, don't expect it to prime unless the air pump is complete and properly assembled. If the previous tenant has replaced the sealed primer bulb with the vented one from another model, don't expect the primer to work.

If you look into the carburetor air intake with the air cleaner removed, you should see fuel come out of the nozzle when you pump the primer bulb. DO NOT TRY TO START THE ENGINE WITH THE AIR CLEANER REMOVED. A lean spit could give you a faceful of burning fuel.

Ahhh, Thanks Grumpy and now I appreciate Jaffa's point a little better too.Unfortunately it's hard to see fuel coming out the venturi because there is a metal guard across the intake area. I think it's the original prime system. It all seems to be good now as it does start first pull with everything back in place...and a couple of primer presses. I repaired that gasket with some aviation gasket goo. Seems to have done the trick. Thanks to all for their help.

Thanks for reporting back, sparker. I'll close the thread.