Just got this cbr running and I don't think I should really call it running lol. It will start up for awhile, idle, but does not have any power at all. it takes awhile to get up to speed even in 1st. Before, it was not running at all because of a bent valve so I bought a new one and without thinking did not check the valve clearances or anything (is this my problem?) I slapped it on and made sure the timing was correct but now I'm starting to doubt myself. I also took the carbs off and cleaned them out. I noticed that the choke really doesn't help any when I'm trying to start it. I am not sure if my problem lies in the carbs or the valves in the head. What do you guys suggest doing? It just has no power my 1980 Honda 400 could beat it with ease lol. I'm thinking about taking it to a mechanic

 

There are quite a few things you can do cheaply on your own before you turn it over to a mechanic, but adjusting valves is out of my comfort zone for sure ;-) Did you think of getting a compression tester? These are really cheap and can give you a basic idea of what each cylinder is doing - but it will not let you know if there is leaking around the valves, etc.. you would need to have a leak down test done to know if your motor is within tolerances... I had this done on a car many years ago, and it did not cost TOO much.....if it is OK then you can work on the fuel and air delivery to try to fix things.

One other thing to do is start the bike and while it is idling, put your fingers on the exhaust header at each cylinder for just a second (don't burn yourself) and see if any are ice cold compared to the others.

When you have the carbs partway off the bike, before taking off the cables, you can see if the choke cable is attached in such a way that it can move the pistons on each carb all the way... check this by pushing on the little lever that actuates the slide and the pistons.. it may not be opening the choke circuit all the way?

With the carbs, I know that I had to do the cleaning a couple of times to get the pilot jets clear so it would come off idle with any power... what does it do when it is in neutral and you slowly rev it as high as it will go? Will it rev past 4 or 5K ?

 

cbr89600 I just bought a 90 cane and I'm having similar issue. I put some seafoam in the tank so I can clean a few things out. It feels kinda sluggish taking off. I havn't free revved it but under load around 4-5k it kinda bogs a little bit. I'm assuming this is dirty carbs? I plan on replacing fuel filter and cleaning the carbs out. What octane do you guys run these things on? Is there anything common i should be aware of?

 

Check those valve clearances! Before you do anything else. If they are tight, it'll give you false readings on compression tester.