Engine boggs

[rocketman17joe]

I have a attex 400 chief w/jlo a bought a new mikuni 34mm carb,it starts and runs great but after about 5 min it boggs and stalls,if i feather the throttle i can keep it running.i dont know if its overheating it dosnt see too hot.

[6X6]

Does it load up with a bunch of smoke and stumble, or does it make a "hollow" sound, just like it's running out of gas. Make sure your fan belt isn't broken or missing, and that there isn't debris in the cooling fins/fan shroud. Most likely though it's fuel. Make sure you have a good flow, if you take the fuel line off the carb and put it into a clear jar and crank it for a couple seconds, you should get a good flow, not a couple drops. I'd change the fuel filter anyways. My guess is somethings making fuel level drop in the carb, or as you get some heat into it it's just getting a bit too lean, which means richening up the carb, cay you post a video of it running / stalling?

[rocketman17joe]

Welli did ck belt its ok fins clean i bought the carb as a kit new with filter,fuel pump all new hoses inc line from the pulse line.and it does sound like a hollow sound but i cant see why itfuns fine for 5 min then boggs

[racerone3]

did you have the engine running ok before you put the new carb on, or are you just getting it running for the first time? if you are just getting it up and running, you might have bad crank seals. once they get warm they might be leaking causing it to run out of fuel.... the fuel pump is actuated by crank case pressure.

[rocketman17joe]

great yes the engine as i understand it sat i put it back in and got it running,how hard is it to do the seals or is their a quick fix?

[racerone3]

i don't know of any kind of quick fix. get a can of ether, and as the engine starts to bog down, spray some between the engine and clutch, if RPM's pick back up, your clutch side seal is bad... kind of hard to get at the other side

[6X6]

Just my 2 cents. If a seal is bad, (I think Race nailed this one) do them both. If one went bad the other is on borrowed time. The trail is a bad place for engine issues, and air leaks can burn down pistons.

[racerone3]

absolutely, while your in there do both!!! it's just hard to test the one on the recoil side... i don't like spraying ether near the charging circuit and points you could try removing the recoil starter and use a propane torch (not lit) to try directing some gas into that area????

[6X6]

i don't like spraying ether near the charging circuit and points

Why? Fire Good! I use carb cleaner, works fine and is less flammable.