Bigger jets for open exhaust?
- TheForumTroll
- Topic Author
- Offline
- User
- Posts: 186
- Thanks: 14
Bigger jets for open exhaust?
20 Jul 2021 12:03 - 20 Jul 2021 23:21
Im getting my carbs cleaned tomorrow and I was thinking if I should get some bigger jets put in as the bike is running lean and got what is closer to magaphones than actual exhausts
It got stock everything else. What does the experts think? Bigger? and by how much in first try?
It got stock everything else. What does the experts think? Bigger? and by how much in first try?
-[ KZ700-A1 '84 ]-
Last edit: 20 Jul 2021 23:21 by TheForumTroll. Reason: Changed title to stop the pitchfork crowd storming the gates
The following user(s) said Thank You: daveo
Please Log in or Create an account to join the conversation.
- SWest
- Offline
- Sustaining Member
- 10 22 2014
- Posts: 23158
- Thanks: 2801
Re: Bigger jets for open exhaust?
20 Jul 2021 19:37
No baffle? Jets won't keep it from falling on it's face at WOT.
Steve
Steve
Z1b1000 1975 Z1b
kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882
kzrider.com/forum/2-engine/597654-poser?start=240#704229
kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882
kzrider.com/forum/2-engine/597654-poser?start=240#704229
Please Log in or Create an account to join the conversation.
- Nessism
- Offline
- Sustaining Member
- Posts: 7506
- Thanks: 2870
Re: Bigger jets for open exhaust?
20 Jul 2021 19:47
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
Please Log in or Create an account to join the conversation.
- ghostdive
- Offline
- User
- Posts: 390
- Thanks: 118
Re: Bigger jets for open exhaust?
20 Jul 2021 20:39
I've run without the baffle in my 4-1 a few times, and once I had the entire cone off for non-fun reasons. I never noticed a significant change in performance or anything, but my jetting is a little rich as-is.
A helpful person might respond to your thread with the standard rigamarole of "do plug chops at varying throttle openings to determine jetting" but some people don't like loud exhausts...anyway, I would personally not really worry about it beyond going up a size or two in the main jet and maybe a half turn out on the idle mixture. It'll be fine.
A helpful person might respond to your thread with the standard rigamarole of "do plug chops at varying throttle openings to determine jetting" but some people don't like loud exhausts...anyway, I would personally not really worry about it beyond going up a size or two in the main jet and maybe a half turn out on the idle mixture. It'll be fine.
1982 KZ750 Spectre - 6 speed swap, BS34s, 18" rear wheel
2001 ZX-6R
2001 ZX-6R
The following user(s) said Thank You: TheForumTroll
Please Log in or Create an account to join the conversation.
- SWest
- Offline
- Sustaining Member
- 10 22 2014
- Posts: 23158
- Thanks: 2801
Re: Bigger jets for open exhaust?
20 Jul 2021 21:31
These engines start making the most power at 7-9000 RPM. Back pressure is your friend.
Steve
Steve
Z1b1000 1975 Z1b
kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882
kzrider.com/forum/2-engine/597654-poser?start=240#704229
kzrider.com/forum/11-projects/598262-kz-...-will-it-live#672882
kzrider.com/forum/2-engine/597654-poser?start=240#704229
Please Log in or Create an account to join the conversation.
- TheForumTroll
- Topic Author
- Offline
- User
- Posts: 186
- Thanks: 14
Re: Bigger jets for open exhaust?
20 Jul 2021 23:09 - 20 Jul 2021 23:11
Well now, sure hit a sore spot there huh?
They do have baffles and they are installed, so no need to be mad. There's even a little stuffing inside too. Still they are open enough to make it run lean, even compared to stock. And besides, it's less loud than 90% of Harleys (99?) even if I pull out all the interior of the exhausts so please calm down
*backs slowly away making calming gestures*
They do have baffles and they are installed, so no need to be mad. There's even a little stuffing inside too. Still they are open enough to make it run lean, even compared to stock. And besides, it's less loud than 90% of Harleys (99?) even if I pull out all the interior of the exhausts so please calm down
*backs slowly away making calming gestures*
-[ KZ700-A1 '84 ]-
Last edit: 20 Jul 2021 23:11 by TheForumTroll.
Please Log in or Create an account to join the conversation.
- daveo
- Offline
- Premium Member
- Posts: 2853
- Thanks: 708
Re: Bigger jets for open exhaust?
20 Jul 2021 23:27Reading your post brought back some really "great" memories of better times for me.
1982 KZ1100-A2
The following user(s) said Thank You: TheForumTroll
Please Log in or Create an account to join the conversation.
- TheForumTroll
- Topic Author
- Offline
- User
- Posts: 186
- Thanks: 14
Please Log in or Create an account to join the conversation.
- TexasKZ
- Offline
- Platinum Member
- Posts: 7658
- Thanks: 2298
Re: Bigger jets for open exhaust?
21 Jul 2021 06:19 - 21 Jul 2021 06:19
As always, the answer depends on the specifics. You may only need to shim the needles a bit or you may need to go up a size or two on the mains. Dynojet may still sell a Stage 1 kit that worked well for many aftermarket systems. There are several ways to check the jetting. The most precise would be to hook up a wide band sniffer to the pipe that can record engine data and go ride the thing under real world conditions.
A less tech and expense intensive method that will get you close is this——
www.factorypro.com/tech/tech_tuning_proc...igh_rpm_engines.html
A less tech and expense intensive method that will get you close is this——
www.factorypro.com/tech/tech_tuning_proc...igh_rpm_engines.html
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: 21 Jul 2021 06:19 by TexasKZ.
The following user(s) said Thank You: TheForumTroll
Please Log in or Create an account to join the conversation.