Stock Carb Jetting: These are the jets that my carburetor was delivered with. This is supposed to be a Type I stock 1600cc jetting.
Idle Jets:
Primary - 60
Secondary - 50
Main Jets:
This set-up is too lean.
Primary - 137
Secondary - 140
This jetting combination does not work for my set-up. The engine runs too lean. I have found that a lean engine causes heat, which in turn causes octane knock (pre detonation of fuel).
Current Jetting Set-up: This set-up seems to work well.
Idle Jets:
Primary - 60
Secondary - 50
Main Jets:
Primary - 140
Secondary - 137
I put in the smaller jet in the secondary to prevent over fueling
the motor when at wide open throttle
After some investigation it was determined that the fuel mixture was not the only cause of the octane knock I was experiencing. It was also caused from a compression ratio that was too large for the engine I had built with the type of fuel I was burning (street gas). The ratio can be lowered and there are definite procedures for determining what the compression ration of the engine is.
I was able to get a good breakdown on the Weber carburetor I purchased.
The kit I bought did not come with much information, so I scanned the breakdowns
and uploaded them. You can view them or right click and save them.
Right click to save the links below.
