I bought a Honda CBR 600 FY 2000 off a friend who had pulled all the fairings off to have them sprayed and didnt want to put them back on so the bike sat for a about a year in a garage before i had it. It had a datatool alarm on it which i pulled out before i could get it going

I changed the Oil and Filter, new Spark Plugs, had to buy a new Regulator/Recifier and cleaned the Air Filter

I put it together and started her up with a bit of coaxing but got there in the end. GREAT. mot next, insurance, ready for the summer, Booked the MOT and started to ride it out my garage. Then it happened, the bike died, engine cut out and was difficult to start

Inspection time, I worked out the symptoms which are the same everytime and are as follows

The engine completely cuts out at around 3500rpm while in 1st gear, Itll rev to the red line in neutral
Its difficult to start after its been started once, itll start first time cold, I have to hold the throttle open wide to start it again

I had a few friends around and they all said it was the carbs and jets. Off they came, cleaned them as well as i know how, measured all i needed to regarding floats using a Haynes Manual, put them back on, SAME SYPTOMS

I then bought another Carb off eBay because i was so sure it was that. SAME SYMPTOMS, so i now have two

Since then, Ive checked the ohms for the Coils and the throttle position sensor and they check out

Ive started the bike with the air filter off and bypassed the Fuel filter and fuel pump. SAME SYMPTOMS

Can anyone help PLEEAASE

 

Hi ,when you say you bypassed the fuel pump and filter did you use an auxillary tank straight into the carbs with air filter off, has yours got the DAI system

 

This is exactly what i did, im not sure if it was the right thing to do but seemed logical at the time. It does have a DAI system, just reading up on it in detail now, Do you think it may have something to do with it

 

Yes , could be the air solenoid , I believe its connected to the speedo , and offers different amounts of air, is it plugged in to the harness and are the air pipes clear

 

CaBaRet Sir, You have fixed all my problems at once. after months of going back and forth to my garage to try and test something new,

I overlooked the DAI system, it turns out the it only kicks in at around 20kph which is equivalent to 3500 rpm roughly which is what made me check the whole system over, just one of the pipes were in the wrong place although it was a difficult find because it looked right even following the Haynes Manual. I took all the air pipes off the above where the carb is and refitted them all following the air flow and voila,

Rides nice and has no hot start problem, A happy ending
And Ive learned so much more about motorbike mechanics and electroncs.

Thank You

 

Glad everything worked out Jonny

 

This is a good example of why forums are great to use. Well done both.