Sprag diode

Vehicles equipped with the 500 cc Rotax engine

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Sprag diode

Postby Cuz » Sat Oct 12, 2013 4:57 am

Hi, was looking at an Mz diode on ebay a month or so ago and wondered if anybody new where to get the diode and if they are worth fitting The seller said it fitted onto the starter solenoid and stopped residual current causing whip to the sprag when the kill button is pressed. Is this right? should I be fitting one?

Cheers

Cuz
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Re: Sprag diode

Postby MZCountryRider » Wed Oct 16, 2013 8:18 am

I don't understand how it would help really. Just use the compression release to shut the engine off.
Charlie
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Re: Sprag diode

Postby DAVID THOMPSON » Wed Oct 16, 2013 8:54 pm

i think is a replacement for what's in there already
and its more to do with radio interference from the bike to tv and radio signals
dave
and bike should always be killed with the compression release ..then key turned off
Dave 2002 MZ RT125+1995 Saxon Tour(500cc)
1997 MZ 660 Traveller+6/13/09 WV USA
"IN the end times the IDIOTS will be in charge
of everything"
"I like the road less traveled if it's PAVED!"
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Re: Sprag diode

Postby davegsm82 » Fri Oct 18, 2013 11:05 am

I can't see the point in this really, is the 500 engine prone to kicking back when it's shut down without using the decompression lever?

The only place I can think that the diode goes is across the starter, this would make the starter motor stop very abruptly as soon as you let go of the start button, instead of winding down slowly under its own momentum. Also, if the engine was to kick back (i.e. if it didn't have enough momentum to get over the next compression cycle as it is shutting down) then the starter would act as a sort of brake.

I can't see how this would be beneficial to the clutch but then again, my 500 doesn't have an electric start... yet... oh if only I could find the sprag and gears :'(

Dave.
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Re: Sprag diode

Postby DAVID THOMPSON » Fri Oct 18, 2013 10:09 pm

the starter acting as a brake if the motor runs backwards is the problem
on the rotax and 125cc bikes and several other bikes
about a 200 plus usd problem $$$$ every time it happens
i have spent more money because of this than i have spent on tires in the last 12 years
dave
Dave 2002 MZ RT125+1995 Saxon Tour(500cc)
1997 MZ 660 Traveller+6/13/09 WV USA
"IN the end times the IDIOTS will be in charge
of everything"
"I like the road less traveled if it's PAVED!"
wd8cyv at yahoo dot com
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Re: Sprag diode

Postby davegsm82 » Thu Oct 24, 2013 7:43 am

David, What exactly happens? Does something break? surely it can't be an inherant design flaw, seeing that this engine is used in so many different things.

I've managed to procure the parts to make mine electric start, so I wan't to know what I should avoid doing with it once it's running!

Dave.
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Re: Sprag diode

Postby DAVID THOMPSON » Thu Oct 24, 2013 8:11 am

always shut it off with compression release if it has one
lots of nice fresh oil in motor always

try not to run bike backwards and let the clutch out in gear ..
this puts it under a big strain
this is used in lots of bikes because it does not take lots of power to run it
like the starter on say a mid 1970's bmw

when the motor runs it is wareing
its one of those GOOD BUT BAD IDEAS about how to start a bike
dave
Dave 2002 MZ RT125+1995 Saxon Tour(500cc)
1997 MZ 660 Traveller+6/13/09 WV USA
"IN the end times the IDIOTS will be in charge
of everything"
"I like the road less traveled if it's PAVED!"
wd8cyv at yahoo dot com
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