Engine sound decel

[Jakobi]

Hi everyone,

Just wondering what everyones engines sound like I decel after blipping with idle. The last few rides I have noticed my bike makes a BRRRRRR kind of sound that is in time with the vibrations the bike makes. Is this normal for the Gas Gas range? I can't think of a time that my bike has not done this but I'm not 100% certain.

I rode a friends 2011 and his felt much smother and didn't make the sound. I have noticed the KTM makes the traditional nang nang nang sound which mine doesn't either.

Is this normal?? At 50hrs I'm thinking it might be time for a re-ring

http://www.youtube.com/watch?v=X0iKTObBOuQ Audio to help.

[swazi_matt]

Jako you trying too hard to find faults with the gas gas!







try replacing the o-rings on the exhaust

[Bailey28]

I think the sounds the engine makes coincide with the jetting setup. Lean, I get a weak buzz, no ding-ding sound.

Too rich I get a "kack" sound ... ding ding.... KACK!... ding.....

Just right I get a whirr, maybe some dinging at the very bottom end. But by then I am happy and the world is a better place and I get back on the gas hard!

[GMP]

Rings at 50hrs in a 300? With good oil/filter service that should go over 100 hrs on a complete top end and retain peak performance.

Like swazi says cherck your orings, also check motor mounts, PV adjustment, and otherchassis hardware. Sometimes the pipe springs vibrate enough to contact the header slightly as well.

[GasTimppa]

My 2011 300 6-days sounded like that after 45 hours. I just changed piston. Old looked like it was used +100 hours . Allways had clean filter properly installed. Jetted properly, no signs of lean mixture.

Bad Vertex item I think.

With new piston bike sounds and runs as new. We made reclamation to factory...

I'm not sure if you have the same problem, but If I was you I'll check the piston...

[bergerhag]

My '10 300 sounds like that too now. 40-ish odd hours on it..

[Jakobi]

Originally Posted by GasTimppa

My 2011 300 6-days sounded like that after 45 hours. I just changed piston. Old looked like it was used +100 hours . Allways had clean filter properly installed. Jetted properly, no signs of lean mixture.

Bad Vertex item I think.

With new piston bike sounds and runs as new. We made reclamation to factory...

I'm not sure if you have the same problem, but If I was you I'll check the piston...

What am I looking for in terms of piston wear? I'll be digging into it to throw some new rings and will replace the piston also if required.

Same deal here. Air filter after every ride always mounted correctly. Air boot always ensured to be sealing. Jetting has always been close. A little too lean at times but always identified and resolved before putting the bike to work. Always 50:1 with GasGas recommended GRO.

Exhaust o-rings replaced as I have also experienced that vibration. Much more tinny sound. Inspected piston through exhaust port. Black coating has worn off piston as expected. No visual signs of scoring exhaust side. No evidence of blow by. Engine mounts are all in spec also. Bike feels it may have lost some of its snap, but by no means feels weak. Still good compression felt through kick starter.

I have noticed the sound does vary somewhat with jetting also. I would consider it the sound bailey speaks of. The WRRRR kind of sound. Only noticable on decel and in idle. So is this just a worn in engine, or is it something worn out? I'll have to dig into it to find the answers.

Whats everyones opinion on cylinder prep? Hone? Scotch Bright?

[bergerhag]

When I think about it, mine started making the noise right after the switch from N1EF to N3EG needle. Could it be jetting related? I need to swap back, see what happens.

[Biff]

Originally Posted by swazi_matt

Jako you trying too hard to find faults with the gas gas!







try replacing the o-rings on the exhaust

Had same noise on my 2010 300 - new exhaust o rings and front mount = sorted
18 months in and loving it

Biff

[SwampGasser]

Jak, that noise is no way related to the piston. The engine speed does not coincide with the rapid clacking noise you have. I would look into the kickstarter area. Perhaps in the clutch. For sure look on the right side of engine.