alternator not charging.

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alternator not charging.

hi. as above, my alternator isn't charging. bike is a gsxr 1100 98 import. okay, because it is an import the alternator specs are different than brit bikes. for example, the stator shaft is shorter by about 5mm so a brit one is too long, and its proving difficult to get the correct size. i have heard late model rf900's are the same spec.
checking the voltage on the 3 wires from the windings @ 5000 rpm each wire measures 2.85 volts. it should be more ? any figures? i have a manual but found no info in alternator section.
there is continuity between the windings and they appear to be insulated from the alternator body.
thanks for any help.

Sounds like the rubber coupling has sheared, common problem on later RF900s as you surmise - part number 36 .....Parts are about £30 and it's not too bad a job, write up on it here -

genius mate. i have found some rubber debris, was wondering where it came from. thanks.

This is how my RF one came about ......   

well i'm not sure i'm out the woods just yet. the alternator is still on the bike as i need to use it tomoz. therefore i haven't taken anything apart just yet. but what i'm thinking is : looking at the coupler you have removed from your rf900, i can see where the splined shaft fits in. i have to phone redcar suzuki spares tomorrow, and they might shed some light on it. but it's as i said earlier, the stator shaft on my (import) alternator is about 5mm shorter than most others. therefore is there a specific coupler or will they all be the same (for the gsxr 1100 and late rf900's.) is it one size for bikes with this coupler design ?

thanks again.,,

EDIT : got me answer,,ta.

i see your alternator shaft is same length as mine, so i'm guessing other 1100's have a different design. just off to check the manual. i already informed redcar it was part 36, as per their diagram.

this is from my suzuki manual

and this is from redcar

i should be okay at that. brill mate.

Yep, the RF 600/900 and the 1100 changed alternator drive shafts part-way through the production run and it can be a lottery as to which type you have. There's a 'solid' drive shaft with longer splines on the alternator rotor or the rubber coupling type with shorter shaft. You can't mix-and match them. You can swap the drive shaft assembly to fit the other type alternator if you can get the bits -  I was given a spare engine that had the earlier solid type drive so I swapped the whole lot last stripdown.My first coupling failed at about 35k miles and the second one looked a bit ropey at 55k miles so I changed it to the solid type as I had all the bits lying around.I managed it with the tank off and the carbs loosened and sat on top of the engine. That lets you take the cover off and lift the drive shaft assembly out to change the coupling after jiggling the alternator out.  The coupling is assymetric so make sure you press it in the correct way round.Good luck.

f the lights get brighter when you kill the engine, the alternator was not charging sufficiently. When doing this test, the lights should be the only load ...

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I was told by a shop that I needed to replace my alternator. I ordered one off ebay and they told me it would fit my GSXR 1100 W model. It was installed and ripped my bike to shreds on the inside. It was for a model R and it ripped the whole rubber boot out because the shaft was too long longer then it was supposed to be. I'm trying to save myself some money here but not having any luck. Do you think all I have to replace is the rubber boot or do I have to replace the whole gear part?

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