I got a cbr 600 f4i 2002 recently, It has -1 front sprocket and stock rear, The chain was extremely tight and so I loosened it so it was good. But I noticed it's perfect like 80% of the chain and than at one spot it gets tighter and tighter than really tight where it has no play, Than it gets loose again to where it's good. I'm wondering if that's a bad chain or something. It's my first bike and so I don't know if that's normal or not.

 

That's a good sign that the chain is worn/stretched. Some chains will have tight spots, but if there is excessive binding, it's time to replace.

Be sure to replace chain and sprockets all at once.

 

That's not normal. Time for a new chain....

After you replace it, remember to take care of it so it will last. Clean and lube it every 500 miles, or sooner if you live in a dusty or wet area.

 

Get yourself a new set of sprockets & chain & follow Incognito's excellent tutorial here...https://cbrforum.com/forum/how-mecha...et-swap-97641/

 

I can help myself but gawk at that writeup everytime it's posted.
Incognito must work at a Brake Cleaner factory. His bike is annoyingly clean.

 

Alright thanks alot! I didn't think that was right. I lubed it up like crazy before I rode it home and checked the chain this morning and can't find the tight spot but i'll be checking everytime I ride. I also checked the psi in the tires oil etc since it's a new bike. The guy had 10 psi in the rear tire and 20 psi in the front! ??? Oil looked like new oil and correct level. Needs some brake pads, He gave me a extra set of tires i'll need to put the back one on soon. I had money saved up for a new turbo manifold for my car but I might throw some at the bike for brake pads and sprocket/chain

 

I'll qualify this with "not my personal experience but I've been told" that some of the budget sprockets are not concentric between the center mount hole and the teeth. That could explain or contribute to your problem if everything else checks out ok.

 

Afam makes a good sprocket set, driven racing has a great set of sprockets.

RK Chains are good, DID .......

Holy crap 10 PSi ....WTF unless you are at the track you need a bit more then that. What kind of tires do you have ?

Also it sounds like your sprockets are out of round the way it binds and releases.

 

I have a friend with a 2003 F4i just like mine but different color. He got the 520 conversion kit it has RK GXW chain whatever color you want, and the supersprox stealth gold sprocket. -1 in front and +2 in rear. Would that be a good combo? $220 shipped, lifetime warranty on sprocket, If it wears out you can ask for a "free" replacement, 20,000 mile warranty on the chain

 

i remember getting my sprockets from Parts Unlimited. they were the cheapest that i could find. And they are also very well made. I see no reason to look else where.