Good deal. Sounds like you are coming along nicely.
The PO probably didn't have the patience to sort it all out.

Also, some people get stuck on the idea that bigger is always better.

Here's a link with pics if you want to give the stick mod a go.

https://cbrforum.com/forum/cbr-600f-...-153118/page2/

 

Thanks.

 

My son finally took out the Hurricane and I rode his 06 after riding the 06 for 2 hours behind my Harley. He did fine with it once he got used to the different clutch (a couple of starts).

 

Very cool. Great time I bet.

 

Stick coil mod completed. Seems to run a bit better. Feel like I am just making little 10% improvements now and getting it closer and closer. I think the 108 main jet might still be too large, bike seems to choke at full throttle. Need to check it out at higher RPM though to be sure it is really a main jet issue.

 

Checking it out at higher RPMs sounds like a good idea. At least you can go have some fun.

 

I raised the float levels a few millimeters since I checked the original floats in these carbs and they were way too low. So just figured what really helped most was moving the floats from the other carbs which were higher (at just around the 8mm mark). So that did the trick as far as getting rid of the remaining hesitation while accelerating from lower RPM. I can now cruise at 2000 RPM with mild acceleration without any kicking, choking etc. I also notice that the flutter I get when I floor it stops at around 4000 RPM and it takes off (hold on or it will leave you on the ground). So the flutter I get below 4000 RPM at full throttle might be the needle. Perhaps I have to lower it a touch since it is pretty much at max height. What do you think?

I am also still a bit puzzled as to why the bike would run good when cold (even with no choke) and then start missing as it warmed up (after 5 minutes) and yet every change I have made is to INCREASE the amount of fuel the bike gets (raised needles, raised float level, bigger main jets). Just for learning purposes, nothing else, since I am happy with how it is progressing.

 

You need to be sure the pilot circuits in the carbs are properly clean. This means taking jets and screws out and spraying cleaner and compressed air both ways. Pilot jets need to be clean and you should see light thru them. I manually clean them with a strand of wire. Pilot screws should be set to 2 1/4 to 2 1/2 turns out to start. Then they should be adjusted to highest RPM when engine is hot. Reset idle to 1200 RPM after pilots are adjusted. Popping, spitting and hesitation between 2-4K is usually due to and issue with the pilot circuit. This is the transition area where the pilot circuit overlaps the needle and mains. If the above does not correct the problem your pilot jets are not sized correctly. Most likely too small.

 

So everything runs good now. I lowered the needles back to where they were in the original carb and that with the raised float levels has fixed everything. I have done more carb cleaning than I ever want to do again. The only remaining question for future reference is why the bike showed signs of being rich (would run worse when warmed up) when the solution was actually to raise the float level. The only guess I have is the float would get some extra gas when the bike would sit and would take a few minutes for them to get to the lower level and then the hesitation would start. But again, I am all set, bike runs excellent now. I appreciate everyone's advise and help.

 

Looks like I might have a 98 CBR to fix next. My son's friend has one of those and it runs terrible. I will be an expert soon and have a garage full of extra jets, cleaning supplies, tuning gear and so on.