5hp briggs and stratton issue

[Brianator]

Could be a fuel supply issue?

So, you put a bunch of new parts on it which you didn't mention if they're stock replacements or upgrades and now this... how was it running before? Do you still have the stock parts?

How about some pictures!?

 

[Clark125]

I’ve already got a new magneto on order so hopefully that’s the issue. Anything else it could be that would cause it to just lose power like that?

Could be a fuel supply issue?

So, you put a bunch of new parts on it which you didn't mention if they're stock replacements or upgrades and now this... how was it running before? Do you still have the stock parts?

How about some pictures!?

So the carb and most everything else are replacements but not oem. Prior to adding the carb/spark plug it would turn over but not run. Getting those on got it running which is an improvement. So now its just the issue where its losing power and hard to restart. The magneto I ordered is stock replacement.

Within the past week all the pictures I try loading error out on upload.

I’ve already got a new magneto on order so hopefully that’s the issue. Anything else it could be that would cause it to just lose power like that?

Could be a fuel supply issue?

So, you put a bunch of new parts on it which you didn't mention if they're stock replacements or upgrades and now this... how was it running before? Do you still have the stock parts?

How about some pictures!?

So the carb and most everything else are replacements but not oem. Prior to adding the carb/spark plug it would turn over but not run. Getting those on got it running which is an improvement. So now its just the issue where its losing power and hard to restart. The magneto I ordered is stock replacement.

Within the past week all the pictures I try loading error out on upload.

Getting upload error below. Which is odd I can upload a picture of the error.

Let’s see if these pictures load.

 

[Brianator]

Okay, stock replacements parts and have enabled it to start that's good! First check fuel flow by pulling the hose off the carb and see if you have a decent consistent flow or if it's a trickle or if it's good then slows down to a trickle

Now spark/ magneto.... while the engine is cold and been sitting for awhile use a spare plug grounded to the motor to inspect spark quality, then when it dies do it again and see if there's a difference.

Those 2 things are free and easy to test so try them and report back please.

We're having photo upload issues atm but I see you figured it out!

 

[Clark125]

Okay, stock replacements parts and have enabled it to start that's good! First check fuel flow by pulling the hose off the carb and see if you have a decent consistent flow or if it's a trickle or if it's good then slows down to a trickle

Now spark/ magneto.... while the engine is cold and been sitting for awhile use a spare plug grounded to the motor to inspect spark quality, then when it dies do it again and see if there's a difference.

Those 2 things are free and easy to test so try them and report back please.

We're having photo upload issues atm but I see you figured it out!

So the carb doesn’t really have a hose I can pull off to check. Has a downtube which pulls gas from the tank. Unless Im missing something.

May order a spark tester and see if theres a difference in spark before and after. With the new magneto on the way I might as well go ahead and replace it to see if it makes a difference.

 

[Brianator]

So the carb doesn’t really have a hose I can pull off to check. Has a downtube which pulls gas from the tank. Unless Im missing something.

My mistake! I didn't notice that in the photo!

 

[Clark125]

My mistake! I didn't notice that in the photo!

All good. If I replace the magneto and it still does it Im not sure what else it could be. It wasn’t like a carb stall either where it would bog down then die this was just a straight power loss.

 

[JTSpeedDemon]

Check compression. Try a new head gasket(easy to replace, just make sure to torque the head down to spec), maybe check valve sealing. Try pulling out the spark plug and squirting oil in the cylinder right after it loses power. Put the spark plug back in, and try starting it. If it starts just fine, you have bad piston rings.

 

[Clark125]

Hoping the magneto is the issue. Would like to get the briggs running but at some point it might have been cheaper to buy a new predator when they go on sale. I do have a backup briggs I got running so I may swap em sometime soon and see if the other one works better.

I don't know much about how governors work but any chance that could be an issue? Doesn’t look like there is a spring going from the bottom of the motor up to the linkage near the carb on this engine.

 

[JTSpeedDemon]

Typically there is a hard linkage between the carburetor and the governor arm, and a spring between the cable plate and the governor arm.

 

[Clark125]

Typically there is a hard linkage between the carburetor and the governor arm, and a spring between the cable plate and the governor arm.

Yeah so that spring attaching to the governor arm is not there on this engine. Came that way from prior owner.

Check compression. Try a new head gasket(easy to replace, just make sure to torque the head down to spec), maybe check valve sealing. Try pulling out the spark plug and squirting oil in the cylinder right after it loses power. Put the spark plug back in, and try starting it. If it starts just fine, you have bad piston rings.

Replaced the magneto armature and no noticeable change. Engine cranks and runs then loses power and dies after about a minute and a half. Pulled the plug and dropped a small amount of oil in, replaced plug and tried cranking it back up. Took about seven pulls then it cranked. Ran same length of time as before and died. Not sure the oil made much difference.

I’ll see if someone has a compression tool of if you have ideas where to get a cheap one to use let me know. If compression was low Ive always been curious how you fix that? Always hear about low compression on old dirt bikes but never really understood it.

 

[Clark125]

Swapped engines today with another briggs I have. Had to cut the end of the throttle cable to get it back through the sheathing. Engine ran fine then the throttle cable stuck somehow inside the sheathing.

Is there a proper way of connecting the cable to the spring side of the throttle rod going to the pedal?