5hp B&S engine wont fire.There is current going through th spark plug wire and the spark plug is good?

Question

any help would be great. it does not have pionts either thanks

Answer 1

I had one with the same problem....it was the valves sticking. Easy enough to remove head and free up. 4 stroke version of course!

Answer 2

no points must be a newer quantim motor they suck now that they have elimenated most the little tricks one used to be able to perform id suggest that first off you remove the tank and drain it then pull off the carberator and clean the best you can replace the diaphram gasket under the carberator put tank back on refuel and see what happens have you removed the plug and grounded it out on the frame or head to make sure it has good fire if all seems good after this and it doesent start is it a lawn mower ?? if someone hit something while cutting grass like a stump or pipe in the ground etc it could then be the shear key which is located under the hat on the top of the crankshaft if the key is sheared off it throws the timing out so it will not start to get to the shear key remove the hat where the pull cord is remove the screen now you must remove the part that the screen was attached to sorry i forget the name of it but it has 2 to four little ears where the screen was attached to it they make a tool for this but i doubt if you have one i use a brass bar to remove it by taking the bar and a hammer place the bar on one of the ears now tap it to the left to loosen then remove being carfull not to lose any of the ball berrings inside remove the washer on top the flywheel now theres a little slot cut in the side of the crankshaft which is where the sheer key is located you should be able to look at this slot and see if the key has been sheared as it will no longer line up if this is the case remove the flywheel by putting the brass bar on top the crank shaft while prying up on the flywheel give it a good wack with the hammer it should come right off now go get a new sheer key and reassemble the motor using a little white greese on the top of the crankshaft etc nows a good time to clean and oil things take a small piece of sand paper to the magnito there are two spots where it allmost touches the flywheel sand them lightly this should solve the problem i know it sounds complicated but its really pretty simple if your mechanicly inclined

Answer 3

Sometimes the magnet on the flywheel rusts up therefore not allowing enough current to flow to the coil causing a weak spark. Remove the pull start case and lightly sand the magnet on the flywheel reinstall and try to start. Hope this helps

Answer 4

I have a couple of 5 hp B&S engines. The filter was dirty on one, I changed it and it starts on the first pull. The other one that I have on a tiller I have to pour gas into the carburator, then it generally starts. This one has the tubes that lead down from the carb into the tank. If I cleaned the carb it would help, you might want to do the same.

Answer 5

Check to see if you are getting gas and that your air cleaner is clean. If thee are also ok, check the counterweight on the flywheel to see if the pin has sheered and this has caused the timing of the electric pulse to the spark plug to be off.

Answer 6

Try removing the spark plug and spray WD40 into the hole and replace spark plug. That should give it enough compression to start...It has worked for me before.

Answer 7

try a new plug. old one can still be fouled. is it getting gas? also be sure magnet on flywheel is not rusty. gap between flywheel & coil needs to be .20 inch.