Hs 45 making a flat weird sound ?

[deanopolini]

Jus bought a hs45 2018 hardleys used it starts fine revs out well then all of a sudden while revving it will kinda go quiet if tho its full bore its hard to say what it sounds like abit like if i held my finger over the exhaust to make it quieter its not a carb bog type sound but after this noise it usually dies but sometimes does it then still revs after it im stumped 

[Wonky]

Have you checked your plug,is it lean/ air leak and hitting the Rev limiter. 

 is it Fuel starvation?

 

its easy to post a youtube link of it running..it takes some of the explanation and interpretation.? 

[deanopolini]

A havent had much chance to look at it yet tho mate but the bloke said he put in a new plug with no change amean i fix stihl stuff myself and never heard a noise like this is doin lol its sound lyk as if you stuffed a rag in the exhaust for a few seconds lol maybe its a sheared flywheel key and its jumping out of timing ?

[GardenKit]

Have had issues in the past with loose lumps of carbon in the muffler getting jammed over the exhaust hole, then dropping away when the revs fall off.

[deanopolini]

Il have a look mate i did notice it seems like the bolts to hold the exhaust on have been sealed in with the red gasket stuff dont think thats normall is it ?

[gary112]

58 minutes ago, deanopolini said:

Il have a look mate i did notice it seems like the bolts to hold the exhaust on have been sealed in with the red gasket stuff dont think thats normall is it ?

I,ve got one and they seem smokey things anyway,ive had to clean the exhaust out on mine before as it seemed like it was choked when running,did that and away it revved,sounds like you might have the same problem

[deanopolini]

Il have alook at tht aswell mate it does sound like its something from the exhaust blocking it in someway i just dont know why its gor red sealant in the bolts amean its onky a 18 pretty new not much use by looks of it 

[deanopolini]

Think i found the problem lads took the exhaust of and it had something rattling round inside shook it and a shard of metal must have broke off inside and kept blocking the hole thus making the flat noise and cutting the engine lucky it didnt drop into the piston runs fine now sorted thanks for help any appreciatsd 

[gary112]

52 minutes ago, deanopolini said:

Think i found the problem lads took the exhaust of and it had something rattling round inside shook it and a shard of metal must have broke off inside and kept blocking the hole thus making the flat noise and cutting the engine lucky it didnt drop into the piston runs fine now sorted thanks for help any appreciatsd 

Bostin job?