strange noise after 4000rpms

[mrGENESIS]

Hi guys my bike makes a strange noise after 4000 rpms the noise almost sounds like its the carbs like when you take to long to switch to reserve when its empty cant explain the noise something like cluck cluck when i let down on the throttle noise goes away is it jets that is blocked or can it be a bearing knock plz

[dash]

I read a post similar to this awhile back and it the poor guy was on a wild goose chase, but it ended up being his chain? I would check the noise and see if it coincides with throttle response and chain tightening? I'm sure one of the seasoned vets here would give more advice.

[kilika2]

Can you hear it with the clutch pulled in while cruising down the street? Do you hear it when the bike is in neutral and you're just revving the bike?

Chris.

[mrGENESIS]

Ok thanx i think its either got something to do with carbs plugs or worst of all maybe a bearing knock but i dont understand. When i close the throttle the noise dissapears i took of the carbs and cleaned them will check it and also after 7000rpms the power drops alot hope its not something major then its bye bye GENI been spending a shit load of money on it

[Lastmile]

Is the oil at the right level? When does it make the noise?

[dash]

Well you know it's not a bearing knock, if it stops on de-throttle. If you are assuming a main bearing? Is it a backfire sound through the carbs?

[mrGENESIS]

Can it be a bigend bearing knock or will a bigend knock make constant noise even when ideling you know the sound the carbs make when you take off the airbox and start the bike without airbox and tank sound similar just alot power if its still making like that will check the fuel lines an tank filter what concerns me is the power dissapears after 7000rpms oil level is good

[mrGENESIS]

Hi guys f g bike is still making like that when i let go littke on the throttle revs go up and noise dissapears only when i turn throtle more than quater it makes the noise gonna change plugs and oil tomorrow can it be the plugs ? Plz guys need help

[dash]

before you dump a bunch of cash on plugs, get a stethoscope and listen to the engine at idle. If there is a main bearing going bad you may not hear it at idle, though unlikely. If a bearing, or anything internal is not right, you will hear it.

[mrGENESIS]

Ok thanx plugs is long due so i must change them will find out what is the prize here on stetoscope

[mrGENESIS]

Bad news its a bearing knock was by one of my bike mech he said its defnitely a bearing and ihave 20days left to drive with it till im on leave so its no more driving for geni

[dash]

I would park it and pull that crank out of there. From experience of losing a steel, stroked small block crank to the same problem, you will be sick when you have to shell out the cash for a new crank instead of just bearings. NOTE: It was a long haul to get home, and I had to drive the hell out if it!

[mrGENESIS]

Ok thanx eish and to get yamaha spares fot it here in s.a is a mission and a half and costs a fortune so i dont know what im gonna do is there anyone that slammed a couple of car bearings in and will it hold right thru the whole rmp range my mech buddy said i must check for car bearings fit it and then sell it but i dont wanna sell it love this bike

[DonTZ125]

Is there no local Yam dealer? Even in another city?

Can your mech tell if it's crank, or conrod?

[mrGENESIS]

Ja got yamaha dealers here if i convert our rand into your dollar its like 150 to 200 dollars for the bearing its a conrod bearing