4 degree offset key and timing marks.

stewbrash · 05-27-2021, 05:32 PM

I acquired the 4 degree offset key and will eventually install when I get a stator gasket...but the big question (Dan?) is...do you need to make a new mark to the right for TDC for when you adjust your valves? I looked for the size of the flywheel and the only info was that a Zongshen 229cc diameter is 110MM. that would make the circumference 346MM. Divide by 360 and you get 1.040MM per degree. So, should the timing mark for true TDC be roughly 4mm to the right of the mark after installing the key?

**JerryHawk250** · 05-27-2021, 05:34 PM

It's not enough off the mark to make a difference when adjusting the valves.

stewbrash · 05-27-2021, 05:40 PM

Jerry, 4 degrees is about 1/8th to 3/16ths of an inch or so. So I'll just go past the mark a hair when I adjust them. Thanks!

stewbrash · 05-27-2021, 06:08 PM

Have to get exact here, 4 mm is 5/32's...or, a 32nd over 1/8th...so

DSM · 05-28-2021, 05:09 AM

It’s not that critical as the cam flat is about 280 degrees and rotates at half the crank speed.

**JerryHawk250** · 05-28-2021, 07:49 AM

Quote:

Originally Posted by DSM

It’s not that critical as the cam flat is about 280 degrees and rotates at half the crank speed.

Yep!

05-27-2021, 05:32 PM	#1
stewbrash Join Date: Oct 2016 Posts: 405	4 degree offset key and timing marks. I acquired the 4 degree offset key and will eventually install when I get a stator gasket...but the big question (Dan?) is...do you need to make a new mark to the right for TDC for when you adjust your valves? I looked for the size of the flywheel and the only info was that a Zongshen 229cc diameter is 110MM. that would make the circumference 346MM. Divide by 360 and you get 1.040MM per degree. So, should the timing mark for true TDC be roughly 4mm to the right of the mark after installing the key?
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05-27-2021, 05:34 PM	#2
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,561	It's not enough off the mark to make a difference when adjusting the valves. __________________ 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S 2004 Honda ST 1300 2016 Black Hawk 250 (sold) Keihin PE30 carb,125 main,38 slow.Pod filter,ported & decked head 10:1 CR,Direct Ignition Coil,15/40Sprockets,NGK DPR8EIX-9,De-Cat,Dual Oil Cooler,Digital Cluster 2016 Cazador180 XL 2014 Coolster150 JerryHawk250.com My YouTube Channel
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05-27-2021, 05:40 PM	#3
stewbrash Join Date: Oct 2016 Posts: 405	Jerry, 4 degrees is about 1/8th to 3/16ths of an inch or so. So I'll just go past the mark a hair when I adjust them. Thanks!
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05-27-2021, 06:08 PM	#4
stewbrash Join Date: Oct 2016 Posts: 405	Have to get exact here, 4 mm is 5/32's...or, a 32nd over 1/8th...so
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05-28-2021, 05:09 AM	#5
DSM Join Date: May 2021 Posts: 40	It’s not that critical as the cam flat is about 280 degrees and rotates at half the crank speed.
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