RPM crusing
- TexasKZ
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Re: RPM crusing
19 May 2023 14:11 - 19 May 2023 14:12
The part of your post that I quoted above makes me wonder if the tachometer is reading 1000 rpm higher than the engine is actually turning.
1982 KZ1000 LTD parts donor
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough
www.kzrider.com/11-projects/620336-anoth...uild-thread?start=24
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough
www.kzrider.com/11-projects/620336-anoth...uild-thread?start=24
Last edit: 19 May 2023 14:12 by TexasKZ.
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- gordone
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Re: RPM crusing
19 May 2023 14:29understand, no I haven’t.The part of your post that I quoted above makes me wonder if the tachometer is reading 1000 rpm higher than the engine is actually turning.
but when I tune in idle I get on 2200-2300, so maybe that is an indication?
I think there is two parallel thing her.
1. RPM properly showing to much.
2. From listen on the engine sound when crusing in 80-90km/h I feel it should have been 1000 lower… I quite often need to verify I’m in 4th gear and have one more gear

1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).
Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
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- TexasKZ
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Re: RPM crusing
19 May 2023 15:00
With stock camshafts, idle should be around 1100. With high performance camshafts, a little higher, but nowhere near 2000.
1982 KZ1000 LTD parts donor
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough
www.kzrider.com/11-projects/620336-anoth...uild-thread?start=24
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough
www.kzrider.com/11-projects/620336-anoth...uild-thread?start=24
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- Injected
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Re: RPM crusing
19 May 2023 15:34 - 19 May 2023 15:35No wonder your reving 6000 at 90KPH... your already 1100-1200 RPM higher than you should be.understand, no I haven’t.The part of your post that I quoted above makes me wonder if the tachometer is reading 1000 rpm higher than the engine is actually turning.
but when I tune in idle I get on 2200-2300, so maybe that is an indication?
I think there is two parallel thing her.
1. RPM properly showing to much.
2. From listen on the engine sound when crusing in 80-90km/h I feel it should have been 1000 lower… I quite often need to verify I’m in 4th gear and have one more gear
1978 KZ650B2 w 1197cc Z1 engine
1977 KZ650B1 w 750cc Spectre engine
1979 KZ650C3 w 831cc Hot Rod engine
1978 KZ650C2 w 762cc DFI project
1977 KZ650C1 stock restoration project
1978 KZ650B2 modified project
1978 KZ650B2 Injected Drag 831cc
1980 Z1 Custom Frame Drag 1327cc
1981 Z50R Honda tow bike
1977 KZ650B1 w 750cc Spectre engine
1979 KZ650C3 w 831cc Hot Rod engine
1978 KZ650C2 w 762cc DFI project
1977 KZ650C1 stock restoration project
1978 KZ650B2 modified project
1978 KZ650B2 Injected Drag 831cc
1980 Z1 Custom Frame Drag 1327cc
1981 Z50R Honda tow bike
Last edit: 19 May 2023 15:35 by Injected. Reason: sp
The following user(s) said Thank You: gordone
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- Nessism
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Re: RPM crusing
20 May 2023 11:12
The stock gearing for your bike is 13/33 for a 2.54 ratio running a 630 chain.
I assume your bike is converted to 530 chain?
Assuming yes, that suggests a 16/40 or 41 sprocket configuration. Since your bike is running a 42 rear sprocket, that means your gearing is lower.
Since you have an 810 kit, with much more torque than stock, you can easily run taller gearing. A 17T front is the easiest change, assuming you have clearance. A double change, including the rear sprocket, is another option. I'd try the 17 front first though.
I assume your bike is converted to 530 chain?
Assuming yes, that suggests a 16/40 or 41 sprocket configuration. Since your bike is running a 42 rear sprocket, that means your gearing is lower.
Since you have an 810 kit, with much more torque than stock, you can easily run taller gearing. A 17T front is the easiest change, assuming you have clearance. A double change, including the rear sprocket, is another option. I'd try the 17 front first though.
Ed
Carb O-ring Kits : www.kzrider.com/forum/3-carburetor/61807...-o-ring-kits?start=0
www.kzrider.com/forum/faq-wiki/618026-new-owner-things-to-know
1981 KZ750E2
www.kzrider.com/forum/11-projects/604901...z750e-project-thread
Carb O-ring Kits : www.kzrider.com/forum/3-carburetor/61807...-o-ring-kits?start=0
www.kzrider.com/forum/faq-wiki/618026-new-owner-things-to-know
1981 KZ750E2
www.kzrider.com/forum/11-projects/604901...z750e-project-thread
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- gordone
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Re: RPM crusing
20 May 2023 14:06 - 20 May 2023 14:09Thank you, 530 chain is correct.The stock gearing for your bike is 13/33 for a 2.54 ratio running a 630 chain.
I assume your bike is converted to 530 chain?
Assuming yes, that suggests a 16/40 or 41 sprocket configuration. Since your bike is running a 42 rear sprocket, that means your gearing is lower.
Since you have an 810 kit, with much more torque than stock, you can easily run taller gearing. A 17T front is the easiest change, assuming you have clearance. A double change, including the rear sprocket, is another option. I'd try the 17 front first though.
I haven’t replace anything (replaced all last time) on the chain/sprocket so replace front sprocket is properly good todo anyway do to wear.
normaly I unddrstand there should be space for 17?
Will the gas consume go down on crusing?
Can I reuse the nute and washer?
1981 KZ650-D4, with 1981 z750L engine (Wiensco 810 big bore).
Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
Project:
www.kzrider.com/forum/11-projects/607213...sr-1981-z750l-engine
Last edit: 20 May 2023 14:09 by gordone.
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- Injected
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Re: RPM crusing
20 May 2023 14:32 - 20 May 2023 14:45
There is room for a 17T front running a 530 non O-ring chain so it clears the stock steel front chain guard.
It may rub with a O-ring chain, not sure.
I had to change my gearing because I could not make it across a intersection without lifting the front wheel. Since then this has been my go to gearing for my non stock 650 builds (750 Spectre engine shown)
It may rub with a O-ring chain, not sure.
I had to change my gearing because I could not make it across a intersection without lifting the front wheel. Since then this has been my go to gearing for my non stock 650 builds (750 Spectre engine shown)
1978 KZ650B2 w 1197cc Z1 engine
1977 KZ650B1 w 750cc Spectre engine
1979 KZ650C3 w 831cc Hot Rod engine
1978 KZ650C2 w 762cc DFI project
1977 KZ650C1 stock restoration project
1978 KZ650B2 modified project
1978 KZ650B2 Injected Drag 831cc
1980 Z1 Custom Frame Drag 1327cc
1981 Z50R Honda tow bike
1977 KZ650B1 w 750cc Spectre engine
1979 KZ650C3 w 831cc Hot Rod engine
1978 KZ650C2 w 762cc DFI project
1977 KZ650C1 stock restoration project
1978 KZ650B2 modified project
1978 KZ650B2 Injected Drag 831cc
1980 Z1 Custom Frame Drag 1327cc
1981 Z50R Honda tow bike
Last edit: 20 May 2023 14:45 by Injected. Reason: pic
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