Hi, first post here on the CBR forum, I just recently picked up a 06 F4i with around 9k miles. I just put new tires on the bike and changed the oil and filter. While riding I am experiencing a jerk/thunk feeling when getting on and off the throttle, and then it immediately smooths out? Is this normal for the sportbike in general. It feels like a drivetrain delay of some sorts.

When reinstalling the rear wheel after the new tires I followed the factory chain slack amount listed in the manual, so I don't think it's the chain, but I am new at bikes so it could be related. Any help is appreciated.

 

yea check your chain tension

 

I may be off in this diagnosis but when I got my F4i throttle smoothness was pretty difficult to find. Over time and with one of those clip on throttle clips and Im much smoother with the throttle and I rarely get the clunks.

 

If your chain is good then check the throttle cable itself. It may just need to be tightened up a lil bit.

 

I snugged up the chain a little, I will report back.

 

Don't over tighten the chain though --- I run mine very loose (particularily on the track) and don't find I get that much lash. An over-tight chain will pull tight - Instead of the shock absorbing the bump, the chain is pulled tight and will limit suspension travel and beat the hell out of the chain and sprockets.

The other point of failure is the cush -- the black rubber wedges in the rear wheel assembly. They act as a cushion between the sprocket and wheel -- these can and do wear. If you're really worn you can actually get lash from them. You can either buy new ones, or I have heard of people putting in thin plastic wedges (cut from margerine containers) to fill up the void left by the worn away rubber. Your mileage may vary.

The other source of lash is from your right hand... but I digress

 

Doing some runs last night and this moring I determined that it's not the chain. I loosened it up back to 1 1/8 slack. Another member mentioned to check the throttle, mine had to much free play I think. Tightening that up helped the problem some, the on off throttle is not as abrupt. I also think I need to get used to the throttle in general.


When I removed my rear wheel the cush rubber wedges looked good and had no visible wear. I cleaned then with silicone spray before reinstalling.

 

All motorcycles have driveline lash, the slack that needs to be taken up by everything before the bike is actually forcing the rear wheel to spin faster. Hondas tend to have less then other makes [although I hear thats not the case with the 08+ 1000rr's]. The f4i does have a twitchy on/off throttle respones though, which made it very hard for me to shift smoothly when I started riding [f4i is my first on road bike].

 

Yeah I posted about this a while back (except I know my chain slack is right). The throttle is On / Off initially despite my best attempts to control the throttle. Max speed change I can do is +-2 mph while under power without the clutch.