- Posts: 14
- Thank you received: 0
Gas in airbox
- Djckay
- Topic Author
- Offline
- User
Hi all,
So after a top end rebuild, running right, then having gas pour out from the overflow I pulled the carbs and replaced the jets and float valves, I used clear tube to set the float height. After a few short rides I noticed a loss of power. This morning I went out to go over a few things before a ride, and the was a ton of gas in the airbox. I mean like half full. I drained the gas and checked the float height again. All 4 carbs float height are normal. I cant smell the oil for gas in the crankcase as everything smell like gas at the moment, but the oil level is higher than normal and a lighter color so I suspect that the is gas in the oil. I know I will need to change the oil, and pull the carbs yet again. But before I do does anyone have any ideas of what is going on to cause this?
1980 KZ550A
Please Log in or Create an account to join the conversation.
- 650ed
- Offline
- User
- Posts: 15344
- Thank you received: 2829
First - your petcock is not operating properly. With the engine off the petcock should prevent fuel from flowing from the tank. If by chance you have a manual petcock rather than a vacuum operated one, do you shut it off when you shut off the engine as you should or if you have the stock vacuum operated petcock are you leaving it in the "RUN" position as you should? If so, you need to rebuild or replace the petcock because it is not working properly.
Second - assuming you set the fuel level correctly, at least one of your float valves is not closing completely or may be sticking open sometimes. Even if you replaced the float valves they can stick open if any crud from the tank gets in them. Do you have an inline fuel filter? If not, you should install one and then carefully clean the float valves to ensure they close all the way every time the fuel has reached the proper level.
One other thing to check is the overflow tubes in the carb bowls. These sometimes develop cracks. When they do fuel will flow from them even if the fuel level is set correctly and the float valves are operating properly. This seem unlikely in your case since there is sufficient fuel flow to have fuel enter the airbox, but it's worth checking while you have the carb blows off. With the carb bowl in hand, just fill it with liquid and see if the liquid leaks out the overflow. Ed
1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
Please Log in or Create an account to join the conversation.
- Nessism
- Offline
- Sustaining Member
- Posts: 7528
- Thank you received: 2841
Please Log in or Create an account to join the conversation.
- Patton
- Offline
- KZr Legend
- Posts: 18640
- Thank you received: 2098
Good Fortune!
1973 Z1
KZ900 LTD
Please Log in or Create an account to join the conversation.
- SWest
- Offline
- Sustaining Member
- 10 22 2014
- Posts: 23015
- Thank you received: 2756
Nessism wrote: Sometimes the petcock's vacuum diphragm fails and fuel flows backwards down the vacuum line and into the carbs/airbox while the bike is parked. Something to check out anyway.
That would be my bet.
Steve
Please Log in or Create an account to join the conversation.
- Djckay
- Topic Author
- Offline
- User
- Posts: 14
- Thank you received: 0
1980 KZ550A
Please Log in or Create an account to join the conversation.
- 650ed
- Offline
- User
- Posts: 15344
- Thank you received: 2829
1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
Please Log in or Create an account to join the conversation.
- Djckay
- Topic Author
- Offline
- User
- Posts: 14
- Thank you received: 0
1980 KZ550A
Please Log in or Create an account to join the conversation.
- 650ed
- Offline
- User
- Posts: 15344
- Thank you received: 2829
1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
Please Log in or Create an account to join the conversation.
- Patton
- Offline
- KZr Legend
- Posts: 18640
- Thank you received: 2098
Djckay wrote: ... Any ideas on where to find a small fuel filter? Thanks
Readily available at most motorcycle dealers, motorcycle repair shops, Z1 Enterprises, etc.
Good Fortune!
1973 Z1
KZ900 LTD
Please Log in or Create an account to join the conversation.
- jakedude
- Offline
- User
- Posts: 201
- Thank you received: 30
Nothing lasts, nothing is finished, and nothing is perfect.
Please Log in or Create an account to join the conversation.
- 650ed
- Offline
- User
- Posts: 15344
- Thank you received: 2829
www.kzrider.com/forum/3-carburetor/59406...ne-and-filter#633243
1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
Please Log in or Create an account to join the conversation.