FZR400 Sprag Clutch

Lukather · Post by **Lukather** » Tue Jul 08, 2014 9:43 pm

anyone know about Sprags

Ok - so got bike back together put new battery on. tried to start and only a wirrig nose on pressing the button. took peanut cover off and tied the starter again. the starter is enguagiing all cogs moving and the sprag stationary

the wheels are all moving and trying to turn the sprag anti clockwise?

I have removed the sprag thinking it was siezed but when removed all looks good rollers and springs no corrossion well oiled

The funning thing is the sprag engauges going clockwise and rotates freely anti clockwise

so first question

should the starter motor be driving these wheels anti clockwise ? the starter is turning clockwise

Anyone have any thoughts on what the problem could be?

cheers

C

banner001 · Post by **banner001** » Tue Jul 08, 2014 11:30 pm

Any chance you have put it on the wrong way round?

Unfortunately clockwise and anticlockwise are relative to which side of the thing you are looking at.

Is it like the fzr1000 sprag clutch, so the sprag clutch pulls a chain attached to the crank, or is the sprag clutch attached to the crank physically? Either way they should lock in the same direction of rotation as the crank.

If it's a fairly standard 3roller 3spring sprag clutch they are usually impossible to assemble incorrectly, but it might be possible to install in in the engine/on the crank in one of 2 ways?

yzfpaul · Post by **yzfpaul** » Wed Jul 09, 2014 6:16 am

there should be a locating pin slot(looks like shark fin) on the shaft that the main sprag gear slots into the starter clutch and it should spin anti clockwise
if your looking at it from the kerbside (nearside)

rofl just cant put it into words that well but my brain can see what needs
to happen sorry Luk

Lukather · Post by **Lukather** » Wed Jul 09, 2014 7:59 am

OK boys. this is my 400 remember

I've had the sprag off and all is well? very clean rollers and springs fine

The outer copper drive ring at the bottom behind the sprag is going anti clockwise when I try to start, and not engaging?

If i turn the copper ring clockwise it engauges and locks up? as if the starter is turning the wrong way?

Thanks for help.

c

banner001 · Post by **banner001** » Wed Jul 09, 2014 9:06 am

from that picture the starter should definitely go anti-clockwise.

all i can suggest is that, make sure you definitely have power going from the +ve battery terminal, through the relay, into the starter motor and not the other way around.

sometimes new batteries have the terminal connections reversed from what the previous battery was...always worth a check as the starter motor will work connected the "wrong" way around...but in reverse.

willandrip · Post by **willandrip** » Wed Jul 09, 2014 10:20 am

Mark;
The crank rotates clockwise when viewed from the rhs.
The sprag clutch is operating correctly.
The starter rotates anticlockwise.
Either the battery terminals are transposed or;
If you charged the new battery before fitting;the charger terminals were transposed and now you have a reversed polarity battery.

In theory the main fuse should have blown when the battery was connected
on the 2TK.
However in practice this is not always the case.

oldskoolexup · Post by **oldskoolexup** » Wed Jul 09, 2014 5:00 pm

at least Yam had the sense to put the sprag clutch on the outside of the crankcase unlike the 1000.....what happened ?????

Lukather · Post by **Lukather** » Wed Jul 09, 2014 7:39 pm

Here's the YouTube link to it working

http://youtu.be/00S1ZiqeffU

I have checked starter seems to be fine solenoid ok ?

Help

Thanks

Lukather · Post by **Lukather** » Wed Jul 09, 2014 8:23 pm

Just notice that you said starter should go anti clock wise mines going clock wise. ??
Mm

Lukather · Post by **Lukather** » Thu Jul 10, 2014 4:15 pm

Ok I've changed poles on solenoid ! Doesn't do anything

Tried different battery new one and it's still throwing starter wrong way

When I change pos for negative on battery it WORKS throws it right way and try's to start then main fuse blows. ????

I now very confused ?

willandrip · Post by **willandrip** » Thu Jul 10, 2014 5:12 pm

Right then Chris; first my apologies for calling you Mark in my first post ; that's senility for you !

I had a dodgy starter in the stores that has lain for 2 years and after your posts yesterday I decided to fix it this morning.
Mine wanted a bearing.
I tested it first and it ran anticlockwise as is intended.

I stripped the armature out and replaced the bearing and tested it .
It span up perfectly.
I did not check the rotation.

Now after reading your last post (just now) I googled "starter rotates wrong way"

This is the important one;
http://xlforum.net/vbportal/forums/arch ... 79287.html
Read from the last 9 posts to the end.

I then went out and tested my rebuilt starter;
IT TURNED THE WRONG WAY = Clockwise.

Fixed it by taking out the two long bolts and rotating the end cap 180 degrees.Do NOT allow the end cap to separate from the body unless you wish to faff on refitting the brushes.

The starter now rotates anti clockwise as it should.

In my case I stripped the whole thing apart initially which I believe had reversed the polarity of the motor.

With yours ; I can only summise that it has stood for quite a while without
any current through it and has self de-polarised.

Anyway it seems a cheap fix; you only have the grief of stripping the starter out.

DO test it on the bench a few times with jump leads after you turn the end cap 180. before refitting.

I learnt something today too; which is nice.

willandrip · Post by **willandrip** » Thu Jul 10, 2014 5:31 pm

Lukather · Post by **Lukather** » Thu Jul 10, 2014 6:01 pm

Thanks bill - a mechanic I know suggested this and I poo pood it right off the bat as the starter hasn't been off the bike !!! I have had the starter apart and yes the bushes are a pain but there are marking in the outer casing to line up so they fit right I have tested another starter and obviously it rotates which way you apply the current

Does the casing fit both ways ? Last chance saloon before I set it on fire and claim on insurance !!! If it was insured !!!

willandrip · Post by **willandrip** » Thu Jul 10, 2014 6:27 pm

I found the grief was keeping the brushes forced back against the springs and trying to insert the armature.

The casing fits both ways ; i.e 180 out.

When I went back into the garage this afternoon for the rotation test; the starter casing was as it has always been. You could tell by the corrosion on the upper surface.
It span clockwise.

I turned the casing 180 and it span anticlockwise.
I then turned it again ; back to what it was originally and it span anticlockwise.

I think once it has been polarised the correct way it stays that way; if you alter the casing you have to check it on the bench a few times.

I advise;
Turn the casing.
Test the rotation.
If it is correct (anticlockwise) turn the casing forward another 180 so it is back to where it was and retest.(this is purely for aesthetics so as the uncorroded shiny side is not upwards and visible.
I do not know if turning the casing itself backwards was the cause of the polarity swap; I just kept turning the casing the one way as far as I remember.

It may depend which way the casing is turned that effects the polarity ?

The starter will physically fit and work whichever way the casing is .

Lukather · Post by **Lukather** » Thu Jul 10, 2014 6:50 pm

Just took starter off and the casing can only fit on one way as it has a lip on the end that goes into where bushes are

Exup 1000

FZR400 Sprag Clutch

FZR400 Sprag Clutch

ok

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