Hello CBR friends,





I was given a “free” 2000 CBR600 f4 that had spent 20 years in heated storage! (12k on the odometer) I’ve spent the winter working on it. It needed a new ignition key as someone had tried to steal it before it was put in storage. (This forum has been VERY helpful especially regarding the 9v diode and pink wire in the ignition) I’ve cleaned the tank, tested the fuel pump, new spark plugs, new filters including the one in the tank. And I’ve had the carbs off: new main and idle jets, reset pilot screws, synchronized the 4 carbs.
SO after many ups and downs it runs great - in the shop.
Yesterday I take it on the road - fun! Yes! - and after 5 miles of going great it looses power and dies. It happened to be on the first decent hill of the ride. Playing with the choke and idle screw I get it to turn over and even run for a few seconds but nothing more than that.

Seems like a fuel problem, not surprising considering the history. Should I take the carbs off (for the fourth time!) or is there something going on electrically with the fuel pump? Maybe the vibration after five miles of riding did something to the relay? Or the pink wire in the ignition?

 

Muck suckled through the internal passages of the carbs?

You don't say you had them cleaned and it's very likely they need it.

 

Did you rebuild the carbs or just replace the jets? I have the exact same bike. Mine sat since 2015 and I got it running in January. Soaked everything I could over night in carb cleaner. Ran a guitar string through every tiny hole. Then I blew every orifice out with compressed air. The next day I did the exact same routine all over again before putting everything together with a rebuild kit.

Does it quit like it is running out of gas and then die? Died on a hill also makes me think about float levels or needle and seat need replacing. Sitting in the garage running on a stand is not going to pull the fuel like running down the road under load. Just a guess.

Also once I put in an external fuel filter on a F2 and rerouted the fuel line to it. I made the line to long and when the tank was on the fuel hose was folding down on itself compressing the line at the bend. I replace the fuel hoses and vacuum lines if they are old and not flexible.

 

I did clean them. Blew carb cleaner through all the orifices etc.

 

They need far more than that - many of the hidden passages are small, twisty and the glaze is hard.

 

Hey there. Welcome. That is a nice-looking bike, especially for the price. I really like the yellow bikes.

@Ed Harris is correct. A thorough cleaning is required. In order to do this, you will separate and fully dissemble each carb. Each passage will need to be gone through multiple times. These carbs must be totally spotless. Afterward, you will need to sync them. I understand it sounds like a lot of work, because it is. It's not overly hard, but it is very tedious. There are multiple videos available to show you the way. There are several of us here that can offer advice too. But there are no shortcuts in this process. You will be chasing never ending gremlins if you try to shorten the process.

 

Thanks, this is all great advice. I was hesitant to separate the carbs especially since the bowls looked surprisingly clean for sitting for so long and the carb cleaner seemed to flow freely out the holes when I blasted it.
But I am probably fooling myself in thinking that it is a random electrical problem. I’ll pull the carbs one more time, give an even deeper clean and tell you how it goes.
Thanks

 

I suggest hitting every orifice with an air compressor. It amazed me how much stuff blew out when I thought I had done a good job cleaning. After seeing compressor blowing out stuff is why I soaked the carbs again for a second day. Good luck. For a 25 year old bike mine runs like it is brand new now. I switched mine over to red because my yellow fairing were so sun faded and I couldn't fine yellow fairings to match. David

 

That looks very nice indeed.