need help please

[ninja bob]

Hey all,
I was checking over my bike yesterday and noticed a rattle after giving it A bit of a rev and then letting it go back to idle,
The rattle lasts about 10 seconds on idle then goes away , it also goes away if I rev the bike at all while its doing it.

With my trusty stephascope I managed to track it to the alternator,

So my problem is what do I do now? Is it A problem or should it b ok to leave,
What should I do?
My bike is a 99 zzr1100

[h.b.bear]

had a rattle in truck gearbox once and once problem was found we worked out to be the diff,so what im saying even thou you think the rattle is coming from alternator it may be travelling from elsewhere on the bike.You will be amazed how much a noise from a machine will travel

[ninja bob]

Hmm will have to give it all good lookin over

[smithy5]

Was it just on initial start up ? Might be just until the oil gets to the top of the motor.
Make sure you have enough oil in it.... should be midway between the two marks when bike is level....

[ninja bob]

No its not on intial start up I was checking it after a 40min ride , its only happening after a rev then it stops till i let i free rev it again it dosent appear to happen underload

[TONY-J]

my dads gpz100rx had what we norrowed down to be a rattly alternater, so we pulled it out to check the cush drive on the back of it but then discovered the bolt on the back of the alternator that holds one part of the cush drive had come almost all the way out allowing that half of the cush drive to move around.

it was a ugly clucky rattle sound.

it could be many things though, are you sure its not the cam chain as that can rattle when you throttle up then left off.

[ninja bob]

Me and my dad had the stephascope on the cam chain cause my first thoughts were the tensioner but there was no noise there that's how I cam to conclusion was from alternator was the cause of the rattle

[TONY-J]

well its pretty easy to pull the alternator out, check it for worn bearings and check the cush drive out for worn /torn/ sloppy rubbers.

with your stethascope can you hear any noise from the right hand side cover? if so could be a sloppy starter chain rubbing on the clutch basket.

good luck mate.

[Strika]

Cam chain!

[ninja bob]

the right hand side sounds prity good, i think ill pull alternator out next weekend since im on night shift for the week now so i will b sleeping a lots ha ha, i found n download a service manual earlyier alternator looks prity easy to remove so i might even just replace the bearings because i got it apart even if they arnt shagged.

thanks for the help =)

[TONY-J]

yeah alternator is 3 bolt i think.

[ninja bob]

finaly pulled alternator n it was exactly wat ur dads bike had done tony, so i pulled bolt out n put thread locker on put it back in and its now quiet as.

i found out to get alternator out i had to take of clutch line ,so since i lost a bit of oil i went to top it up and i cant belive how dirty the reserver was it had think sludge and some of it was rock hard had to scrape it off with a screw driver, so im glade i had to open it now i flushed system and put new fluid in and the clutch feels alot better now

[TONY-J]

sweet good to hear, atleast its was a easy fix.