New 5hp Problems

[jackeo21]

Hey all,

Our newest purchase is a 1974 Briggs 5hp. It doesn't look like it has much use on it. After getting it to spark I put it back together but it still would not run. It only runs with your hand over the carb. It wont even run with choke.

The previous owner put a new jet and diaphram in it, but that did not seem to make a difference. Could the problem be at the tubes that go into the tank? You can hear and feel the carb sucking in air. With my hand over it it will run for a good 30 seconds. Maybe just a good cleanout will do the trick It has backfired about 3 times.

Other than that it has never been apart and is all original. Surprising for a New Zealand Briggs I guess :shrug:

I have used the search feature :thumbsup:

 

[CarPlayLB]

Check the key on the flywheel. It may have sheared

 

[dakota]

air/fuel screw @ 1 1/2 turns - new plug - clean carb - should run.

 

[jackeo21]

I know that the key is not sheared :thumbsup:

I have played with the air/fuel screw until it runs a little better. It has a near new plug. The carb could use a clean I guess. Could be a valve seat issue? I revved it to about 3600 - 3700rpm (as far as it will let me go at the moment) with my hand over the carb and it shot out fire :laugh: Pouring fuel down the carb down the plug hole or the carb makes the recoil, recoil very fast.

 

[jackeo21]

She runs now! Pulling the gas tank and carb, cleaning, and a put back together did nothing at all. But an adjustment of the jet screw made it run, and rev properly. I'd say it hasn't run in 20 odd years. :thumbsup: we have re-threaded the carb/air cleaner hole and are going to use a wing nut to hold the air filter on. Even the air filter has some sort of rare metal grill...

 

[jackeo21]

Just wondering if there could possibly be a ball bearing hiding behind the crankcase cover? It has the rubber seal on the back, but its extended out so I would think there is? If so how do I go about timing the cam without removing the bearing?