you can probably shim them... but again that is only to acheive a certain change to make it perform as it should, not better... then their is float height - but Again that is only to make it work properly... not better.

 

I'm going to leave it for now since it still runs good and is still fast. I know it would be faster with the jet kit, but I don't want the down time or to spend the money right now.

 

ya...have u ever been to the track bumblebee?

 

I have a full yosh exhaust, and not sure what filter is in it. Around 9K any gear and 1/2 to WOT it hesitates very badly until it gets into the 10.5k rpm range. Just wondering if anyone would contribute this symptom to improper jetting or if it would be in relation to something else. Any help would be greatly appreciated. Thanks

 

This seems to be the solution the shop is working for my bike right now. I have a K&N and M4 exhaust on my f4. I had the carbs cleaned professionally (because i hate messing with carbs). Afterwords the shop called to say it idled fine now but when they road tested it, it died on them twice. When he pulled the plugs he said they were VERY lean. They re-checked the carbs and couldnt understand why it was happening. I told him i had just replaced the fuel filter, fuel pump and plugs on my own and he confirmed that they all were working fine. He said after talking with the other mechanics they all agree its because of my exhaust and filter. They are ordering a Jet kit for the carbs right now so hopefully it will solve the problem. I'm pissed because i never had a problem with my setup before, but whatever.. at this point i really just want my bike back. It at least makes sense in my mind that if the carbs were as dirty as he said they were, that the air mixture in the carbs might have been restricted until now which allowed my setup to function. The idea of a little extra pull is definitly a nice thought though....

 

my bike was rejetted, but iwth good reason...
i have a '99 F4

the head has been ported, polished, and milled down

it also has a slightly more aggressive intake cam(it would have had a more agressive exhaust cam aswell but it arrived broken...

that andyoshi exhaust...

anyway mine only has a 'stage 1' jet kit(what ever that means)

it does runslightlylean in a few places, but hey thats a carb for you

 

I would say this makes sense in logic terms. If stock bike=good and stock bike with fullexhaust=worse performance than the jets would have to be resized to accomadate faster fuel delivery do to the faster escaping exhaust gas. That said if stock bike with slip-on=good and stock bike with slip-on and k/n=worse performance then the jets would also have to be resized to accomadate the increased airflow. So.... with THAT said, it would make sense to say that the stock air filters actually restrict the airflow enough to make it run stable. Has anyone tried running there bike without the filter for a short bit to see if performance would be negatively affected, if so, it would confirm that theory. Easiest way to say- just plain have to get the mix right. From growing up racing motocross, I was taught to adjust carbs on the actual feeling of power and of spark plug coloring/fouling. A lot can be told by the way it looks in the jug.