Hey guys I need some help. I've got a 2000 f4. It's my first sport bike and I'm lost on where to start to fix the issue. Bike starts right up and will go thru first gear like a champ. Soon as I go above 50 it bogs down and won't go above 7k rpm and won't go faster than 65. I covered the ram air tubes half way with duck tape and it runs like a champ other than the idle being a little high at 2k. With the tubes covered the bike will go all the way to 14k and 170. It just looks stupid with the tape. Any ideas on where to start to get it all the way right? I appreciate any help since no shop in my area willeven look at the bike.

 

Hi JohnRebel welcome to the forum.
Sorry to hear about your issue.... I presume that the bike is new to you and you have no idea of its history?
It would seem that from your description it is an air / fuel mixture issue, it could be something as simple as does it have the air filter fitted? If that is the case then you will need to look a the carbs and make sure that they are set up as though from the factory and in particular the mixture screw.
If that does not sort it then they might need fully stripping down and checking float heights etc to make sure that the PO has not been messing with them. If it comes to that there are various very good and detailed guides to help with properly stripping and cleaning the carbs.
Cheers
Al

 

Thanks for starting to give me some ideas. Your right that I don't know much about the bike history. I had it shipped from Kansas to Michigan sight unseen. Only had it a month and it was stolen and wrecked. Took me awhile to replace all the plastics and controls. The bike had a receipt from 2020 saying the carbs were rebuilt. I put a kn air filter in and it came with a 2 Brothers slip on. Other than that tho I don't know much. It's only got 9400 miles on it so should have a lot of life left once I get this straightened out

 

As you say, it is barely run in so should be great when your little challenge is sorted.
The slip on should not be an issue, however I have heard some discussions over the years that some carbed CBR's do not like the K&N air filter, I did not have a problem on my F3 but it has been reported. As a quick trial you could try the paper one and see if it makes a difference.
Do you have any pics? What damage was done? May point to an issue.

 

For info Troubleshooting from the manual

 

How the bike was when i got it.

After stolen and wrecked



How it currently sits

Side fairings i havent put on yet

 

Here's some pics of the bike. I don't believe it was the kn air filter bc it did it from the start. I'm going to hopefully get the bike taken apart and see if I can find any of the issues you told me about this weekend. I'll give you and update afterwards. I appreciate the help bc I didn't want to just throw parts at it while guessing and really want the bike ready to ride when it warms up. Figure next year I'll be ready to move up to a liter bike if I get this season of riding in

 

Most likely carbs need complete disassembly and restoration.

 

That's such a shame, but you have done a really nice job on the re-build. I really like the colour very stealthy!!
As above probably a carb removal and rebuild then
Do not be in a rush to move up to a 1l bike, these are more than fast enough and certainly as in my case more of a bike than I will ever be as a rider.
Get good gear and learn how to ride and you will be surprised that in most cases you would be able to keep up with any other bikes and these handle really well.

 

B4 I start the adventure of trying to figure out the carb rebuild... wouldn't the bike run terrible or have trouble getting up towards the top end on speed if my carbs were dirty? I'm a little nervous about attempting the rebuild on my own