Here's some facts:

• Bought a 98 CBR600 as a non-running bike. PO claimed to have ridden it daily in the last year and that carbs only needed to be cleaned.
• Carbs were disassembled, thoroughly cleaned, and replaced bowl gasket and pilot screw gasket
• Pilot screws were adjusted to factory starting spec of 1.5 turns out
• New K&N air filter installed
• Tank filled with 93 octane gas
• one short hose left over since carb rebuild. No open outlets visible.
• Idles fine, throttle revs all the way up the RPM scale. no backfiring
• While in gear, first gear will rev to about 10k before bogging down
• 2nd gear revs to about 6k before bogging down
• Can't successfully get past 40mph
• Engine dies after slowing to a stop, suspected as lack of fuel
• Spark plugs were reported to have been replaced within the last year. I inspected one and it looked good and new
• I jumper power directly to the fuel pump when I suspected perhaps the fuel pump relay was faulty. The bike reacted the same.

Here's what I think should be done and MIGHT resolve the issue:

• Properly tune the pilot jets from the starting position
• Test the fuel pump output to ensure that it's pumping the spec'ed amount.

Any other suggestions or thoughts?

 

Here's a pic of the left over hose. Any know what it goes to??

https://www.dropbox.com/s/pmioffcy0e...405_142028.jpg

 

Any suggestions?

 

Just wanted to let you guys know I tracked down the issue. Bad fuel pump contacts (who knew lol). It simply didn't pump fast enough at high speeds, causing it to bog down and loss power. I simply removed it and did a gravity feed from the tank into carbs. I ordered the new contacts to fix in a few days.

 

Thanks for posting a follow up. My bike Is doing almost the same thing. I'll have to take a look at mine. Thanks again!