- Posts: 190
- Thank you received: 84
Back to original airbox from pods - Adjustment needed?
- cartal
- Topic Author
- Offline
- User
Less
More
06 Jan 2022 11:19 #860088
by cartal
Back to original airbox from pods - Adjustment needed? was created by cartal
Hi guys,
Over xmas I spent some time taking off my pods and putting in the original airbox with silencer. The bike is a 1976 Kz900A4. I also took off a 4-1 marving exhaust, and got in a lovely 4-4 replica exhaust.
Carburation had been done less than a year ago with the pods and the Marving, and the bike worked really well. Points were new and adjusted.
I went for a test ride today, with the new setup, and it works well up to 4-5k RPMs. It will not go over that, and seems to "surge" when it reaches that range. Bike starts great and idles great.
I´m a bit lost. Has the engine become richer or leaner? What should I try to get this better? Will ajusting my mixture screws solve the problem?
Thank you!
PD: By the by; I tried the 4-4 without internal baffles, and the bike is way too noisy! Beautiful sound with baffles
Over xmas I spent some time taking off my pods and putting in the original airbox with silencer. The bike is a 1976 Kz900A4. I also took off a 4-1 marving exhaust, and got in a lovely 4-4 replica exhaust.
Carburation had been done less than a year ago with the pods and the Marving, and the bike worked really well. Points were new and adjusted.
I went for a test ride today, with the new setup, and it works well up to 4-5k RPMs. It will not go over that, and seems to "surge" when it reaches that range. Bike starts great and idles great.
I´m a bit lost. Has the engine become richer or leaner? What should I try to get this better? Will ajusting my mixture screws solve the problem?
Thank you!
PD: By the by; I tried the 4-4 without internal baffles, and the bike is way too noisy! Beautiful sound with baffles
Please Log in or Create an account to join the conversation.
- zed1015
- Offline
- User
Less
More
- Posts: 3033
- Thank you received: 1567
06 Jan 2022 11:56 - 06 Jan 2022 11:57 #860091
by zed1015
AIR CORRECTOR JETS FOR VM CARBS AND ETHANOL RESISTANT VITON CHOKE PLUNGER SEAL REPLACMENT FOR ALL CLASSIC AND MODERN MOTORCYCLE CARBURETTORS
kzrider.com/forum/23-for-sale/611992-air-corrector-jets-
Replied by zed1015 on topic Back to original airbox from pods - Adjustment needed?
You will currently be running too rich and need to ensure that the jet needle is in the middle groove (number 3) and that the pilot and main jet are returned to the original sizes.
This information for the correct jet sizes will be in the workshop manual for your machine.
Be wary of some 4-4 replica exhausts as some are known to be restrictive.
This information for the correct jet sizes will be in the workshop manual for your machine.
Be wary of some 4-4 replica exhausts as some are known to be restrictive.
AIR CORRECTOR JETS FOR VM CARBS AND ETHANOL RESISTANT VITON CHOKE PLUNGER SEAL REPLACMENT FOR ALL CLASSIC AND MODERN MOTORCYCLE CARBURETTORS
kzrider.com/forum/23-for-sale/611992-air-corrector-jets-
Last edit: 06 Jan 2022 11:57 by zed1015.
The following user(s) said Thank You: taildragger1197, cartal
Please Log in or Create an account to join the conversation.
- ckahleer
- Offline
- User
Less
More
- Posts: 434
- Thank you received: 143
06 Jan 2022 12:49 #860095
by ckahleer
94 KE100
81 CM200t
82 KZ305
85 VF1100c
Replied by ckahleer on topic Back to original airbox from pods - Adjustment needed?
Are you seeing black smoke when you hit 4 to 5 krpm?
Ride a few minutes at 5K rpm. Hit the kill switch and pull the clutch lever. Coast to a spot you can check the plugs.
Another way I check for too rich or too lean, is to go for a quick ride with out the air cleaner filter. See if the bike runs better or worst.
Ride a few minutes at 5K rpm. Hit the kill switch and pull the clutch lever. Coast to a spot you can check the plugs.
Another way I check for too rich or too lean, is to go for a quick ride with out the air cleaner filter. See if the bike runs better or worst.
94 KE100
81 CM200t
82 KZ305
85 VF1100c
The following user(s) said Thank You: cartal
Please Log in or Create an account to join the conversation.
- Mikaw
- Offline
- Sustaining Member
Less
More
- Posts: 5007
- Thank you received: 1918
06 Jan 2022 12:53 #860096
by Mikaw
1976 KZ 900 A4 kzrider.com/forum/11-projects/613548-1976-kz-900-a4
1976 KZ 900 B1 LTD
1978 KZ 1000 B2 LTD
1980 KZ 750 E1
Kowledge Speaks, But Wisdom Listens.
Jimi Hendrix.
Replied by Mikaw on topic Back to original airbox from pods - Adjustment needed?
What carbs. 26mm with air pilots. Meaning the pilot adjustments will be on an angle off the front of carbs (airbox side) those would be the original. I ask because if you don’t have a manual, I do and will look up factory jet sizes later this evening. I think it’s 15 pilot, 110 main.
1976 KZ 900 A4 kzrider.com/forum/11-projects/613548-1976-kz-900-a4
1976 KZ 900 B1 LTD
1978 KZ 1000 B2 LTD
1980 KZ 750 E1
Kowledge Speaks, But Wisdom Listens.
Jimi Hendrix.
Please Log in or Create an account to join the conversation.
- cartal
- Topic Author
- Offline
- User
Less
More
- Posts: 190
- Thank you received: 84
06 Jan 2022 12:57 #860097
by cartal
Replied by cartal on topic Back to original airbox from pods - Adjustment needed?
Yes. This is my next move. Take out the air filter element and silencer, and see if it behaves differently.
Please Log in or Create an account to join the conversation.
- cartal
- Topic Author
- Offline
- User
Less
More
- Posts: 190
- Thank you received: 84
06 Jan 2022 12:58 #860098
by cartal
Replied by cartal on topic Back to original airbox from pods - Adjustment needed?
Thank you. Carbs are stock 26mm. No pilot on the side, but in the bottom of the carb.
Please Log in or Create an account to join the conversation.
- hardrockminer
- Away
- Sustaining Member
Less
More
- Posts: 3041
- Thank you received: 1092
06 Jan 2022 12:58 #860099
by hardrockminer
I have several restored bikes along with a 2006 Goldwing with a sidecar. My wife has a 2019 Suzuki DR 650 for on and off road.
Replied by hardrockminer on topic Back to original airbox from pods - Adjustment needed?
The original jets were 115 main jet, 17.5 pilot jet and 5DL31 needles. Those are for the VM26SS carbs with the fuel/air screw on the intake side of the carb. Needles should be in position 3 as zed1015 has said.
I have several restored bikes along with a 2006 Goldwing with a sidecar. My wife has a 2019 Suzuki DR 650 for on and off road.
The following user(s) said Thank You: Mikaw, cartal
Please Log in or Create an account to join the conversation.
- Mikaw
- Offline
- Sustaining Member
Less
More
- Posts: 5007
- Thank you received: 1918
06 Jan 2022 13:13 #860103
by Mikaw
1976 KZ 900 A4 kzrider.com/forum/11-projects/613548-1976-kz-900-a4
1976 KZ 900 B1 LTD
1978 KZ 1000 B2 LTD
1980 KZ 750 E1
Kowledge Speaks, But Wisdom Listens.
Jimi Hendrix.
Replied by Mikaw on topic Back to original airbox from pods - Adjustment needed?
Just FYI, those are factory carbs (stock) but not original to your bike. Claim is they are a tad better then you bikes original. I don’t like them, got tired of melting my hand trying to adjust the #2,3, carbs.Thank you. Carbs are stock 26mm. No pilot on the side, but in the bottom of the carb.
1976 KZ 900 A4 kzrider.com/forum/11-projects/613548-1976-kz-900-a4
1976 KZ 900 B1 LTD
1978 KZ 1000 B2 LTD
1980 KZ 750 E1
Kowledge Speaks, But Wisdom Listens.
Jimi Hendrix.
Please Log in or Create an account to join the conversation.
- zed1015
- Offline
- User
Less
More
- Posts: 3033
- Thank you received: 1567
06 Jan 2022 13:22 - 06 Jan 2022 13:34 #860107
by zed1015
Removing the filter element etc will improve the current carburation because you will be removing a restriction and leaning off the mixture..
This will increase the air ratio closer to what the current jetting required for running pods but frankly is pointless and a waste of time if you want to run the stock airbox.
Whatever you do apart from refitting the pods etc will require a change of jetting which cannot be avoided or got around by removing parts of the intake to try and match the airflow to the current jetting.
AIR CORRECTOR JETS FOR VM CARBS AND ETHANOL RESISTANT VITON CHOKE PLUNGER SEAL REPLACMENT FOR ALL CLASSIC AND MODERN MOTORCYCLE CARBURETTORS
kzrider.com/forum/23-for-sale/611992-air-corrector-jets-
Replied by zed1015 on topic Back to original airbox from pods - Adjustment needed?
Just put the carb settings back to stock and you should be good to go.Yes. This is my next move. Take out the air filter element and silencer, and see if it behaves differently.
Removing the filter element etc will improve the current carburation because you will be removing a restriction and leaning off the mixture..
This will increase the air ratio closer to what the current jetting required for running pods but frankly is pointless and a waste of time if you want to run the stock airbox.
Whatever you do apart from refitting the pods etc will require a change of jetting which cannot be avoided or got around by removing parts of the intake to try and match the airflow to the current jetting.
AIR CORRECTOR JETS FOR VM CARBS AND ETHANOL RESISTANT VITON CHOKE PLUNGER SEAL REPLACMENT FOR ALL CLASSIC AND MODERN MOTORCYCLE CARBURETTORS
kzrider.com/forum/23-for-sale/611992-air-corrector-jets-
Last edit: 06 Jan 2022 13:34 by zed1015.
The following user(s) said Thank You: cartal
Please Log in or Create an account to join the conversation.
- cartal
- Topic Author
- Offline
- User
Less
More
- Posts: 190
- Thank you received: 84
07 Jan 2022 01:40 #860144
by cartal
Replied by cartal on topic Back to original airbox from pods - Adjustment needed?
Indeed. I will have to have it rejetted. I just want to try without the filter… but I’ll have to have it done. It’s beyond my abilities
Please Log in or Create an account to join the conversation.
- hardrockminer
- Away
- Sustaining Member
Less
More
- Posts: 3041
- Thank you received: 1092
07 Jan 2022 04:47 #860148
by hardrockminer
I have several restored bikes along with a 2006 Goldwing with a sidecar. My wife has a 2019 Suzuki DR 650 for on and off road.
Replied by hardrockminer on topic Back to original airbox from pods - Adjustment needed?
There were two versions of those carbs. The standard version had 107.5 jets and 5CN8 needles. The LTD version had 105 main jets with 5DL31 needles and 15 pilot jets. In both versions the needles were set in the middle (3) position.
A common reason for running rich is the choke plunger seal is worn. When you pull the choke plunger you can see the seal on the bottom. zed1015 can rebuild them for you.
A common reason for running rich is the choke plunger seal is worn. When you pull the choke plunger you can see the seal on the bottom. zed1015 can rebuild them for you.
I have several restored bikes along with a 2006 Goldwing with a sidecar. My wife has a 2019 Suzuki DR 650 for on and off road.
The following user(s) said Thank You: zed1015, Mikaw, cartal
Please Log in or Create an account to join the conversation.
- cartal
- Topic Author
- Offline
- User
Less
More
- Posts: 190
- Thank you received: 84
07 Jan 2022 10:38 #860156
by cartal
Replied by cartal on topic Back to original airbox from pods - Adjustment needed?
OK. Went for a test ride today, taking off the snorkel silencer (the 2-eyed contraption), but leaving the filter in place. The bike ran a bit better, with the ability to rise to 7-8k rpm, but feeling still "heavy".
Inspired by your comments, I´ve taken the plunge into my main jets, as they can be replaced with the carbs in place. I do have another set of carbs (with a side regulation bolt, as @mikaw said. Findings are:
1.- Current jets on bike are 115
2.- Jets on my other set of carbs are 102,5
I can´t say if the needle is in the 3rd slot, as I don´t want to go into the carbs; but I´m tempted to just plugging in the 102,5 jets, and see how it goes.
What do you guys think?
Inspired by your comments, I´ve taken the plunge into my main jets, as they can be replaced with the carbs in place. I do have another set of carbs (with a side regulation bolt, as @mikaw said. Findings are:
1.- Current jets on bike are 115
2.- Jets on my other set of carbs are 102,5
I can´t say if the needle is in the 3rd slot, as I don´t want to go into the carbs; but I´m tempted to just plugging in the 102,5 jets, and see how it goes.
What do you guys think?
Please Log in or Create an account to join the conversation.