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83 KZ1100 Rejetting
- Patton
-
- Offline
- KZr Legend
12 Apr 2008 01:54 - 12 Apr 2008 02:03 #205850
by Patton
1973 Z1
KZ900 LTD
Replied by Patton on topic 83 KZ1100 Rejetting
Hello, Mike! 
Welcome to the site! We're glad you're here! 
I also enjoy 4/1 exhausts and airboxes with K/N filters.
As known, carb performance is based on all the other tuning components, and even a perfect carb cannot compensate for deficiencies in compression, ignition, fuel supply, etc. I believe that's a main reason underlying advice recommending a full tune up before addressing carb adjustments. And would also check the service fuel level inside the float bowl via the quick easy clear plastic tube method, which requires no disassembly (carbs and fuel tank remain on the bike). Because the fuel level also influences fuel mixture.
Typically, engine performance with a better flowing exhaust and air filter benefits from larger jetting. An educated guess from a highly experienced professional (such as wiredgeorge) may often immediately hit the bull's eye, as could suggestions from other members with the same bike and set-up. If forced here to wild guess, I would say use the next larger size main jet over stock and not change the primary jet until need for larger might be later indicated.
If doubtful about any of the non-carb tuning components, before changing either jet size, would first do a compression test and check/adjust valve clearances, install brand new spark plugs, assure battery is up to snuff, check for good fat blue spark, assure correct ignition timing, and then perform a high speed plug chop test to provide a baseline plug reading for future reference.
Imo, after all is said and done, spark plug reading is one of the best methods to determine the optimal main jet size.
Again, WELCOME! And Good Luck!
Welcome to the site! We're glad you're here! I also enjoy 4/1 exhausts and airboxes with K/N filters.
As known, carb performance is based on all the other tuning components, and even a perfect carb cannot compensate for deficiencies in compression, ignition, fuel supply, etc. I believe that's a main reason underlying advice recommending a full tune up before addressing carb adjustments. And would also check the service fuel level inside the float bowl via the quick easy clear plastic tube method, which requires no disassembly (carbs and fuel tank remain on the bike). Because the fuel level also influences fuel mixture.
Typically, engine performance with a better flowing exhaust and air filter benefits from larger jetting. An educated guess from a highly experienced professional (such as wiredgeorge) may often immediately hit the bull's eye, as could suggestions from other members with the same bike and set-up. If forced here to wild guess, I would say use the next larger size main jet over stock and not change the primary jet until need for larger might be later indicated.
If doubtful about any of the non-carb tuning components, before changing either jet size, would first do a compression test and check/adjust valve clearances, install brand new spark plugs, assure battery is up to snuff, check for good fat blue spark, assure correct ignition timing, and then perform a high speed plug chop test to provide a baseline plug reading for future reference.
Imo, after all is said and done, spark plug reading is one of the best methods to determine the optimal main jet size.
Again, WELCOME!
And Good Luck! 1973 Z1
KZ900 LTD
Last edit: 12 Apr 2008 02:03 by Patton.
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