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Open exhaust jetting?
- Frosty
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11 Sep 2011 00:58 - 11 Sep 2011 01:00 #475828
by Frosty
Open exhaust jetting? was created by Frosty
Sorry if this has been covered before. I havent been able to find a thread that involved the exhaust only.
Heres the deal.
I have and 81 kz440. Runs great other than the megaphone mufflers in pretty bad condition.
I would like to cut them off and replace with some insert baffles and chrome turn-down tips. I have the stock air box on and plan to leave it that way.
My question is, with the above set up, what size jets would you first try?
The carb currently has its stock jets (other than the main) in, which I believe are 65-primary main, 85-secondary, and 125-pilot.
Again, sorry if this has been covered before.
-J
Heres the deal.
I have and 81 kz440. Runs great other than the megaphone mufflers in pretty bad condition.
I would like to cut them off and replace with some insert baffles and chrome turn-down tips. I have the stock air box on and plan to leave it that way.
My question is, with the above set up, what size jets would you first try?
The carb currently has its stock jets (other than the main) in, which I believe are 65-primary main, 85-secondary, and 125-pilot.
Again, sorry if this has been covered before.
-J
Last edit: 11 Sep 2011 01:00 by Frosty.
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- Nebr_Rex
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11 Sep 2011 11:08 #475892
by Nebr_Rex
2002 ZRX1200R
81 GPz1100
79 KZ1000st daily ride
79 KZ1000mk2 prodject
78 KZ650sr
78 KZ650b
81 KZ750e
80 KZ750ltd
77 KZ400/440 cafe project
76 KZ400/440 Fuel Injected
www.dotheton.com/forum/index.php?topic=39120.0
.
Replied by Nebr_Rex on topic Open exhaust jetting?
Do a search at KZ400.com (plenty of model specific info.) and here for carb jetting.
More post on the subject than you can shake a stick at.
Every bike is different,displacement,climate and altitude(?),riding style and demands,
fuel octane and quality,and what has been changed from stock.
You will have to be the one to decide on what jetting to use,but a general idea of where to start can be obtained from those post.
More post on the subject than you can shake a stick at.
Every bike is different,displacement,climate and altitude(?),riding style and demands,
fuel octane and quality,and what has been changed from stock.
You will have to be the one to decide on what jetting to use,but a general idea of where to start can be obtained from those post.
2002 ZRX1200R
81 GPz1100
79 KZ1000st daily ride
79 KZ1000mk2 prodject
78 KZ650sr
78 KZ650b
81 KZ750e
80 KZ750ltd
77 KZ400/440 cafe project
76 KZ400/440 Fuel Injected
www.dotheton.com/forum/index.php?topic=39120.0
.
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- Frosty
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13 Oct 2011 11:03 #482918
by Frosty
Replied by Frosty on topic Open exhaust jetting?
When trying different jets, how far do you go up or down in the jet number to affect anything. I am trying to avoid buying way more jets than I actually need.
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- loudhvx
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13 Oct 2011 11:43 #482922
by loudhvx
1981 KZ550 D1 gpz.
Kz550 valve train warning.
Other links.
Replied by loudhvx on topic Open exhaust jetting?
For exhaust changes, I typically see around 5% on the main jet, but with a totally open exhaust, you might go a little more. Maybe 10% or 15%. It's harder to guess with CV carbs like yours.
Start with just the main and see what happens.
Start with just the main and see what happens.
1981 KZ550 D1 gpz.
Kz550 valve train warning.
Other links.
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- Frosty
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14 Oct 2011 10:22 #483139
by Frosty
Replied by Frosty on topic Open exhaust jetting?
Thanks for the direction.
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