OutdoorKing Repair Forum Forums Repairs and Maintenance Questions On Ride On Mowers Questions On Ride On Mowers Frames mtd with b&s 18hp v twin backfires when stopped

well i got my push mower all sorted now i have a mtd ride on it had a blown motor i rebuilt the engine and it workes fine starts well, runs great, but when you stop it it back fires very loud did put a carby kit in it when i rebuilt it but did not tune it up left it as it was did not want to play with settings was my first rebuild have used it for about 5 hours now with no probs just need to fix this back fire issue and find a nulch plug people i brought it off lost it .

bassman when you say you rebuilt the motor did you take the crank case cover off and remove the tappet gear?

You will need to lap the valves in and check the seats and then reset the valve clearance?

I would be looking at the valves first and setting the clearance to see if that fixes your problem but I will need the model type and code to give you the correct settings.

yes i did take the cover off only paid a couple of hundred bucks for it had snapped connecting rods i think thats what there called thay move the pisston up and down replaced crank rods gaskets and afew little pices cleand it all up when i put valves in i adjusted the cleareance to the manual specs but might have made a mistake there it only happens if the engines at full revs ie. if you hope off the seat but will recheck the clearence to make sure its ok the engine is a b&s intek v twin model 407777 thanks bruce