Lawnmower trouble

Stephen93

I've got a Briggs and Stratton 450 engine lawnmower. Just fixed it up today as a mouse had 3aten the primer bulb. Fitted the new primer and it's working.

Started the mower after few pulls and it runs great.

The issue km having is it's very hard to start. Will only start after priming it every time and takes a few good pulls and some times then won't start.

I've another mower exactly the same which runs fine and doesnt have the issue. So I have checked the spark plug, air filter, done a carb clean and still having this issue. Any advice would be appreciated.

GinSoaked

Sounds like manky fuel left over winter or old dried up fuel. My answer and its not necessarily the best is to dump all the old petrol clean out what you can and then run a liter of Aspen fuel through the machine to help clean out any gum or water. If there was a lot of water in the petrol then that can eat away aluminum carbs so might need a really good strip down clean but iirc the complete carb units for those aren't expensive.

Stephen93

GinSoaked wrote: »

Sounds like manky fuel left over winter or old dried up fuel. My answer and its not necessarily the best is to dump all the old petrol clean out what you can and then run a liter of Aspen fuel through the machine to help clean out any gum or water. If there was a lot of water in the petrol then that can eat away aluminum carbs so might need a really good strip down clean but iirc the complete carb units for those aren't expensive.

Thanks for your reply. Do you think I should take carb off the other mower and try it on the dodgy one first before I order a new carb or am I risking too much? Maybe just try the Aspen fuel and see what happens?

GinSoaked

A liter of Aspen fuel will cost about €6 so if it works its a cheap fix. Its a fuel with no ethanol in it so it can't absorb more water it will also dissolve a lot of the gum if petrol left overwinter evaporated away.

I'm not 100% sure but I think the 450 might have a float chamber. Google youtube for fixes for that engine and you'll see how to open up the carburetta clean the needle valve and empty out any water (if it has a float).

Gen.Zhukov

I had a problem with a B&S before. It did start but ran like there was diesel in it.
Did a change of the carb diaphragm kit and it was like new.


https://www.mowerparts.ie/briggs--stratton-carburetor-diaphragm-kit-795083-433-p.asp

Stephen93

Gen.Zhukov wrote: »

I had a problem with a B&S before. It did start but ran like there was diesel in it.
Did a change of the carb diaphragm kit and it was like new.



Yeah it sounds rough when it's going. I can get it to go after 2 or 3 pulls and it runs fine but sometimes I can keep trying and it just wont start.

I'll try the carb change and see what happens.

Thanks

Gen.Zhukov

It's just that kit I linked that needs changing. The fact that it's readily available, to me, means it's a basic consumable item.