2.5 degree offset drive key.

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Jeff B
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Location: Wisconsin

2.5 degree offset drive key.

#1 Post by Jeff B » Mon Jul 02, 2018 1:20 pm

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I precision machined a pair of these 2.5 degree offset drive keys a while back. They correct crank timing so they both hit top dead center at the same time. I will never use this spare. If someone wants it I'll let it go for $30US plus shipping.

RC45
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Re: 2.5 degree offset drive key.

#2 Post by RC45 » Mon Jul 02, 2018 5:04 pm

I'll take it.
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ns86
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Re: 2.5 degree offset drive key.

#3 Post by ns86 » Mon Jul 02, 2018 6:43 pm

Any spec's you care to post as far as dimensions to mill one?
1986 RG500
1985 RZ500
1986 NS400 HRC
1994 NSR250sp Rothhmans
1983 NS250 p
1987 RG250 WW p
1983 RG250 p
1992 RGV500 WW
1992 RGV500 Lucky Strike
1989 TZR500 Biaggi 3ma p
1984 RZV500 Rainey p

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Jeff B
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Location: Wisconsin

Re: 2.5 degree offset drive key.

#4 Post by Jeff B » Mon Jul 02, 2018 10:13 pm

I made it a decade ago. 2.5 degrees was perfect for my bike. It's a fussy little part. You just take the standard key sizes and rotate the outer half of it 2.5 degrees around the crank centerline.

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tacky1
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Re: 2.5 degree offset drive key.

#5 Post by tacky1 » Tue Jul 03, 2018 12:25 am

Jeff B wrote:I made it a decade ago. 2.5 degrees was perfect for my bike. It's a fussy little part. You just take the standard key sizes and rotate the outer half of it 2.5 degrees around the crank centerline.
Did it make any difference to how the bike ran, Just curious.

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Jeff B
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Re: 2.5 degree offset drive key.

#6 Post by Jeff B » Tue Jul 03, 2018 1:17 pm

It didn't run before I rebuilt it with the key. I believe that the extra rear cylinder spark advance contributes to rear piston failures. I wouldn't expect noticeable performance gains.

MK
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Re: 2.5 degree offset drive key.

#7 Post by MK » Tue Jul 03, 2018 2:24 pm

You guys are aware that you can set a bank offset between front/rear with a decent programmable ignition like the Zeeltronic.

That doesn't correct the mechanical TDC offset but at least each cylinder fires where it should if properly adjusted.
Bye
Martin

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