Reassembled the engine and it's running different

[wbilotta]

This is the first time I've pulled an engine apart but it went back together and is running better. I replaced the springs, shave the eyebrow, replaced the breather, installed an aftermarket air filter, replaced the fuel pump spring, cap and gasket, lapped the valves, set the lash.

The engine runs great but now when I'm running wide open the engine will cut out for a second, come back on, cut out, etc. The gas pedal is cabled directly to the carb linkage and the spring going down to the governor arm is disconnected. Is the governor cutting out the spark somehow ? I'm not sure how the governor limits the rpm's.

Thanks...

 

[moetrout]

What engine?

 

[wbilotta]

Briggs 5hp #130202

 

[Affair_driven]

Is the governor cutting out the spark somehow ?

No.
Sounds like it's surging, result of lean mixture.

 

[wbilotta]

No.
Sounds like it's surging, result of lean mixture.

The carb is stock and it does make a lot popping sounds when I get off the gas. Is it possible to drill out the main jet to enrichen the mixture ? The carb is the style with the pull out choke in the rear of the carb.

 

[Affair_driven]

Is it possible to drill out the main jet to enrichen the mixture ?

Yes. Need a wire gauge drill set and a pin vise.
If current jet size is .052", then go to next size of .053 or .054" or larger.
If you go too big, jet will have to be replaced as there is no way of restoring metal that was reamed out.
Trial and error will get you there.
No burrs allowed.

 

[wbilotta]

Pin vise ?

 

[Affair_driven]

Like a tiny drill chuck. Must be done manually.

 

[Carlman]

Sounds like theres an air leak mate, get some liquid gasket on your carb or buy a new gasket for your intake, same thing happened on my gx120.

 

[Affair_driven]

Were not new gaskets used and everything torqued to spec and tested?

 

[wbilotta]

Were not new gaskets used and everything torqued to spec and tested?

New head gasket, intake, exhaust, carb to gas tank, breather.

The kart is acting the same way my car does when I get past 115 mph. It cuts out for a second then comes back on....

I'm looking on Ebay for the drill bits. What size range should I be looking for ?

 

[vandancouver]

why not just adjust the fuel/air mix?

 

[vandancouver]

set your engine on some jacks, run it wide open then start adjusting

 

[Kaptain Krunch]

Most newer small engines have no other adjustments besides idle. Plus if he is running it ungoverned (which i assume after all that he is), than holding it wide open under no load will only end with a dead engine.

 

[wbilotta]

why not just adjust the fuel/air mix?

I thought the air screw on the side of the carb only handled the air/fuel mixture for the idle and low rpm's and the main jet handled the rest ?