Wont start have topress primer butten then it starts but wont keep running

Pump still runs because hasn't started and is in cold start mode. Get power to the coil to get it running first, then see if the pump shuts down when switch is off.

changing the filter wont help,you need to change the filter / primer housing unit.happend on an isuzu i worked on about 3 years ago.changed the whole unit and it worked like new.

a hole in the primer bulb or gas line it could be a pin hole right in the primer bulb itself and when you hold the bulb you might be holding the hole itself which keeps it running....

Inccrease the line pressure to 90 PSI, a air ratchet is a very high volume air tool and the compressor may not be able to keep up with it.

carby service required

Inside the primer bulb there is a umbrella check valve that need to be replace. It is causing air in the fuel system

Your diagfram is bad replace it in your carb and you will be ok

Try adjusting the idle. The will be a couple adjustment screws, there will be an (H) and (L) you will need to turn the (L) First tighten the sdcrew completely then turn it 1-1/4 turns. This will be a good to start. Then just turn it small amounts until you get it to idle. Also there should be an idle adjustment you can adjust.

Thats called the primer Make sure the on/off switch is on the on,Push the primer at least 4 to 5 times,then pull it..once it starts you may have to push the primer a few more times to keep it running once it runs on its own and you dont have to push the primer to keep it running Cut Away,Also one more thing you probably already Know make sure its full of bar oil..Hope this helps you and have a great day...

I’m happy to assist further over the phone at https://www.6ya.com/expert/joe_a3369546f8067589

Try pumping the primer till it's full of fuel, then start the saw