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That horrible whirring noise

Posted: Mon Mar 22, 2010 12:38 pm
by Falcoholic
I fitted my new starter motor at the weekend and when i thumb the starter it doesn't seem to be engaging. All I'm getting is that bloody whirring noise. I have bench tested the starter motor and all appears well.

Somebody please tell me I've not done another sprag before I go and strip the pesky thing.

:smt013 :smt012

Posted: Mon Mar 22, 2010 1:37 pm
by D-Rider
Based on another thread .... it could be a noise made by a discarded McDonalds toy .....

.... but sounds worryingly like a sprag failure (not that I've had this myself but what I guess it sounds like)

Posted: Mon Mar 22, 2010 1:40 pm
by tommy
I did have the same problem a few months ago. Turned out to be the starter relay. Try shorting the connections on the relay with a screw driver and see if that spins it over

Posted: Wed Mar 24, 2010 12:07 pm
by Falcoholic
Well I pulled the flywheel and had a wee inspect and all appears well with the sprag.

So now I'm totally flumoxed :smt017

All appears to turn well, when i crank the flywheel round it turns the engine ok so I'm presuming the cam chain hasn't snapped.

I still have it all to put back together again yet to se if anything I have done so far has made a difference.

Is there owt I should do before I refit the stator and casing etc other than loctite everything?

Confused of Galston.

:smt012

Posted: Wed Mar 24, 2010 4:20 pm
by Chabby
Can you put it on back to front? :smt017

Posted: Wed Mar 24, 2010 4:30 pm
by Kwackerz
Make sure all the connections are clean, bright and tight.

Posted: Wed Mar 24, 2010 7:07 pm
by exupmonkey
interference from yer pacemaker I'd bet :smt003

Re: That horrible whirring noise

Posted: Wed Mar 24, 2010 8:49 pm
by Falcopops
Falcoholic wrote:I fitted my new starter motor at the weekend and when i thumb the starter it doesn't seem to be engaging. All I'm getting is that bloody whirring noise. I have bench tested the starter motor and all appears well.

Somebody please tell me I've not done another sprag before I go and strip the pesky thing.

:smt013 :smt012
Did you chang the sprag and starter at the same time? or did the old starter work with the current sprag?

Have you still got the old starter motor to compare the new one with?

I'm thinking that if the motor is whirring then I'd suspect it's running ok, just not engaging the sprag. If the new and old starters measure up the same from fitting flange to sprocket then the sprag gear must be in a different position.

Posted: Wed Mar 24, 2010 10:27 pm
by HowardQ
Dale's comments are exactly what I was thinking Andy.
Never changed starter or sprag on a Falco, but if the starter is just spinning round, something is not connecting, so it has to be the first area to check.
Hope you get it sorted quickly mate!

Posted: Thu Mar 25, 2010 12:05 pm
by Falcoholic
The starter motor is exactly the same as he old one. Even down to the numbers on the label.
I have spun the starter with the flywheel off and all appears well.
I'm gonna put it all back together at the weekend and give it another try.

Weird i tell ya....really weird.

:smt017

Posted: Thu Mar 25, 2010 1:49 pm
by HowardQ
Silly comment as I have never seen a Falco starter but .........
The cogged bit at the end of the starter isn't spinning on the shaft for some reason is it? Is there a key missing or something?
Cos if the starter is spinning, it is linked to the flywheel teeth, then the flywheel has to turn with it. :smt017

:smt017 :smt017 :smt017 :smt017

Clutching at straws I know.
Good luck again!

Posted: Thu Mar 25, 2010 9:18 pm
by Falcopops
Good call Howard and made me think. Dangerous, I know, but here goes nuttin.

From what I remember of the diagrams (never opened it up) the starter is always engaged with the sprag ring, i.e. there's no solenoid to throw the starter ring in to engage the sprag.

When the engine starts it spins the other part of the sprag faster than the started does its bit and that's when the sprag does its job.

So, if the starter is deffo meshing with the sprag and its not turning the engine, then the sprag isn't connecting the starter to the crank.

Did you put the sprag together correctly? I'm not sure it's possible, but I'm thinking like a bicycle freewheel it drives one way but not the other. So if you did get the motor to fire (bump start) it would spin the crap out of the starter.

Mind you could all be bollocks!

Posted: Fri Mar 26, 2010 1:37 pm
by HowardQ
That sounds even more likely Dale, my thoughts were hindered by not having seen or fully understood how the sprag works. Almost all starter cogs are pre-engaged onto the flywheel ring so it does not leave much to slip.

Posted: Fri Mar 26, 2010 5:26 pm
by Chabby
Falcopops wrote:Good call Howard and made me think. Dangerous, I know, but here goes nuttin.

From what I remember of the diagrams (never opened it up) the starter is always engaged with the sprag ring, i.e. there's no solenoid to throw the starter ring in to engage the sprag.

When the engine starts it spins the other part of the sprag faster than the started does its bit and that's when the sprag does its job.

So, if the starter is deffo meshing with the sprag and its not turning the engine, then the sprag isn't connecting the starter to the crank.

Did you put the sprag together correctly? I'm not sure it's possible, but I'm thinking like a bicycle freewheel it drives one way but not the other. So if you did get the motor to fire (bump start) it would spin the crap out of the starter.

Mind you could all be bollocks!


A long winded version of what I said in the first place - Can you put it on back to front?

Posted: Sat Mar 27, 2010 1:34 pm
by Falcopops
Chabby wrote:A long winded version of what I said in the first place - Can you put it on back to front?
I see now, I thought you meant sort of inside out, but that's clearly a bit stupid. Damn inciteful right off the bat! :smt023