Noise after top end

stabak

stabak

New member
Well, changed to a new piston on my 300 09 but after an easy start for the first cycle a rattling noise appeared on idle together with the crispier sound of the new piston. When clutch engaged get's quieter... but still there.. mainly clutchside coming

Is it normal or maybe the pv got some how messed up and needs re alignment ? I'll shoot a vid tomorrow...

thanks in advance.. noob here
 
Rev the bike and put you foot up on the top of the pipe and push down. If it makes it go away or reduces it significantly, change your exhaust flange O-rings. They wear out very fast on these bikes.
 
The PV assembly has some decent tolerances to allow it to work even after some carbon build up so if you cleaned down the pv assembly it may have some more play and clack a little at idle. The exhaust spigot can vibe. The clutch always makes a bit of a hollowish noise as well which is always worse when not engaged and quiets up when you pull the clutch.
 
Thanks for the replies guys but don't think its the exhaust. Checked the pv again and the governor on rest looks like this :

11.jpg


while the valve looks like this :

22.jpg


Here is also the video if it helps : http://www.youtube.com/watch?v=B2Vu3TUuAyc&feature=youtu.be

Haven't ridden it to be honest, just heat cycled it.... While reving the pv bracket doesn't move... is it supposed so?
Could have anything loosened clutchside, governor balls etc? Producing this sound or is it normal? What could have loosened by the removal of the cylinder?

Any help would be much appreciated....
 
What kind of piston did you put in? I had this happen to me before on an old RM250 I used to own. I found out from a shop mech. that the forged steel (ie. Wiesco) pistons are noisier than the others. Supposedly they are stronger but make more noise. :confused:.

Some of you engine savvy guys may be able to shine a light on this for us.
 
A brand new S3 marked A as it came with the purchase of the (used) bike... actualy didn't have such a problem before and I thought I put the new one just to be on the safe side.. :confused: The old piston looked good as the cylinder but didn't really knew how many hours it had... :confused:

guess you don't fix smg if it isn;t broken :D
 
stabak said:
Thanks for the replies guys but don't think its the exhaust. Checked the pv again and the governor on rest looks like this :

Haven't ridden it to be honest, just heat cycled it.... While reving the pv bracket doesn't move... is it supposed so?
Could have anything loosened clutchside, governor balls etc? Producing this sound or is it normal? What could have loosened by the removal of the cylinder?

Any help would be much appreciated....
Click to expand...


I don't hear anything all that unusual from the video. Some whirring sound which changes a few times. Maybe when you pulled the clutch?? Sounds normal and is way more noticable once you focus your ears on it.

The PV plate and position of the valve itself are correct for at idle. The PV arm is meant to push the plate up when you rev the bike which opens the valve. If its not pushing then my suggestion is to pull the arm back off the plate and manually move the plate back and forwards and view the operation of the plate and the valve. If they work smoothly and don't bind then you'll need to look towards the governor. If the PV is binding tight enough it may be stopping the governor from opening the valve. My bike did the opposite once where it got stuck at the other end WOT and the engine sounded like it was falling apart.

If you recall pulling upwards on the actuator arm while working on the bike, or putting the pv through its range of motion manually with the arm attached, then its very likely you've dislodged a ball.

I also personally like to take the stops off the pv plate and let the valv cycle a full 360 degrees both forwards and backwards to ensure smooth action.

You should probably consider pulling the whole PV and giving it a clean if you haven't already. Heres a pretty good step by step demo: http://www.gasgasons.com/index.php?site=static&staticID=133
 
Jakobi said:
I don't hear anything all that unusual from the video. Some whirring sound which changes a few times. Maybe when you pulled the clutch?? Sounds normal and is way more noticable once you focus your ears on it.
Click to expand...

Yes, when I pull the clutch it sounds normal. I have a friends GG and compared indeed makes an extra sound/noise ...

I'll try to clean and ensure the pv works correctly, then check for dislodged balls and get back to you...
 
stabak said:
Yes, when I pull the clutch it sounds normal. I have a friends GG and compared indeed makes an extra sound/noise ...

I'll try to clean and ensure the pv works correctly, then check for dislodged balls and get back to you...
Click to expand...

Had a nasty crash once and ended up with dislodged balls...:confused:
 
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