soad

OK SO! I checked the swingarm bearing by doing this: Removed the rear wheel, and unbolted the bottom shock mount and removed the nut. I did this under a covered parking space, and it has a large I-beam above it, so using two ratchet straps, I hoisted the rear of the bike up by the subframe(an F4i has this weird bar thing under the rear seat, it was easy and sturdy) and supported some of the bikes weight using a jack under the exhaust. It wasn't the sturdiest, but it works pretty well. Then I jiggled the shit out of my swingarm every which way, and I couldn't get any play to occur. So I do believe I ruled that one out. I ran out of daylight today, so tomorrow I will check my throttle cable, and fuel pressure regulator. Also, I rode it around a tad, the clunk, it is also on throttle roll OFF as well as ON. It's just a lot more prevalent on throttle roll ON. I don't think I mentioned this before, but i have a PCIII(non usb) and a Jardine RT-One slip on, and the map loaded on the PCIII is the one off the site for a f4i with a jardine rt-one and a K&N filter. however, the problem was still there when there was the stock map on it. And for reference, here is a pic of my sprocket wear.

The F4i has the CCT problem, however my symptoms don't really point towards that being the problem. This weekend is supposed to be warm, so I'm going to find some time to check all of these potential causes out hopefully. I'll get back to you guys and let you know how it went!

It is definitely abnormal. this clunk is pretty severe. enough to make my butthole clench on throttle roll on in a corner. what say you guys about the culprit being a bad swingarm bearing?

this is true. thank you for your help, though. if i can't nail this down by spring, it'll be going somewhere for them to fix it.

So far, I found ONE post on a stunt forum (F4i's are a very popular stuntbike) that mentions something about a pressure regulator being bad that could cause a problem like this. the OP in that thread replaced his throttle bodies with a used set and ended up with very similar problems. However there wasn't a response in the thread about it after it was posted. any thoughts on that? or out of sync throttle bodies?

The chain and sprockets, although not brand new, show no excessive wear, and it is properly lubed and adjusted. that was my very first thought outside of "man i suck at throttle control!" I figured since the FI light doubles as the CEL, it would be worth noting that theres no DTC's

Also, my FI light is not on, so no codes. the FI light does work though. one time i forgot to plug in the IAT sensor after replacing my air filter, and it lit up.

Just describing the symptoms to friends that ride, several people said look into the cush drive in the wheel. I replaced them, but the old ones weren't even bad. hardly any wear on them. the problem did not change a bit, so it wasn't the cush drive.

Ok, SO! I need some help trying to figure this one out. On my bike(2003 CBR600F4i, 43,xxx miles) there is a strange "clunk" that i get on throttle roll on. it happens in any gear, at all ranges of rpm. the higher the rpm, the more pronounced it is, too. no matter how slowly and smoothly i roll on the gas, it will always appear if i am coming from a no throttle situation. my chain and sprockets are good, and properly lubed and adjusted, my cush drive is good. everyone i talked to said it was that so i replaced them. still there. this clunk, it feels very...mechanical. like, there is too much clearance between two parts, and when i let off the throttle, the gap is too big. when i lay on the throttle, the gap closes very quickly, causing the clunk, and it lurches you. i took my bike to mid ohio last year, and it made me kind of scared a few times in the corners. It's kind of like if you were cruising, and you pulled in the clutch and revved it up a little above your cruising rpm, and just dumped the clutch. seeing as how i plan on hitting the track a lot more often this summer, this problem concerns me a lot. it is also very annoying riding on the street. What could possibly cause this!?! any help would be greatly appreciated, even thinking out loud. thanks!

Whats the story with that framed 5.0 mustang magazine?

Yeah that was very unfortunate! This was my first trackday, and I was dragging knee! my instructor, dennis, said I was doing a pretty good job, I had a blast and learned a lot about my riding(I was too far forward in the seat this whole time, put my ass back and it made a world of difference!) Needless to say, you'll be seeing more of me! I'm hooked!

No? How do I find out?

Are you cool? if so, I got you homie.

To all of you coming out on the 14th, my bike is in the sig, if you see me, come say hey! it's my first trackday, and it'd be nice to have a trackday veteran to talk to. also, i rented a garage for me and my friend.

I'll be going on the 14th only.

I couldn't figure it out. I am guessing it has something to do with the valves themselves, and I'm not confident enough to crack open the guts of my forks to rebuild them and check it out, nor do i have, or am i willing, to spend the kind of money a job like that commands. I guess i'll just have to deal with it. :-(

what size regular shoe do you wear?

I bought a used 2 piece alpinestars leathers. I'm pretty proud of myself, just wanted to let you guys know. Feel like batman(with a gut) wearing them, they're all black, lol.

LMFAO!!!!! thats genius!

i was looking at the vega sport II's for boots, and the AGV sport willow gloves. any thoughts? not to sound like a homo or anything, but that sale iron pony has on the alpinestars, they were all blue in my size, and that wouldn't match anything of mine, lol. I like the idea of the bike prep thing. that's good thinking. which reminds me, I'm due up for an oil change. I tried out some repsol 4t oil last oil change, and i noticed a difference in feel of the shifting. it felt more..metallic and hard, i suppose. Do you think if i used a heavier weight oil, like 10w50, it would help smooth out the shifting? you don't think thats too heavy for regular street use, do you?

Thank you, keith stone.

I'm thinking about doing my first trackday at Mid-Ohio on August 13-14, and I have some questions for you frequent trackdayers. Boots. Do they have to be actual race type boots, or will Icon Super Duty 3's be fine? Obviously this is for the novice class. what about other over the ankle motorcycle shoes? Since I don't own a set of leathers, I've been searching high and low for a used set in my size near me. Would you rather have them slightly snug, or a little large? Measuring myself according to sizing charts, depending on the brand, I'm right about a 46, so if you know anybody selling, I'm in the market! but 46 isn't available to rent from Mid-Ohio. Also, is anybody here planning on going? the event isn't on NESBA or STT, it's from the Mid-Ohio school, so does that make it any different? thanks for your help, guys!

Thanks guys, I'll check it out soon. let you know what it was and the fix, for future reference.

Nothing? Nobody?

do you still have the gloves?