lonnie1977
03-28-2009, 07:48 PM
This is for a freind of mine. He has a 04 YFZ450 with a motor built by CT. Has a 513 Falicon with adjustable cam gears 13.5/1 compression, Ported head by CT, N Motion tall jug, Custom Web Cams, Stock carb Bored to 43mm, Fuel intake, Dasa Exhaust, Programable Dayna with four cutom maps from CT and a bunch of other stuff probably not important.
Motor ran great in last May but the decompression arm on the cam came off and it had to go back to CT for repair. Only the motor was sent back with out the carb I believe. Well the first time pilot was a 50 dont remeber the main. We were in Little sahara so it was dynoed and the A/F was good. Motor comes back and it wont start. Go over everything and cant find any thing wrong. Re timed the cams, checked compression, replaces CDI. No luck. Put a 42 pilot in it and it started right up. sounded/felt a little rich so he kept playing with it. It is now down to a 38 pilot and the air/fuel screw all the way in and it still runs. Turn it out 2 turns and it is a little hard starting.
Why would there be such a huge difference and that Pilot is really small compared to the first time. Any idea what we can look for. Oh almost forgot it also has the R&D fuel bowl. I'm running a 42 pilot on my bike with no problems with the mods below. Dealer said the 38 is as small as the jets come. The pipe glows a bright red at idle whitch I know is OK not any more then when it did when it was stock.
Any one have an idea why the jet needs to be so small?
Motor ran great in last May but the decompression arm on the cam came off and it had to go back to CT for repair. Only the motor was sent back with out the carb I believe. Well the first time pilot was a 50 dont remeber the main. We were in Little sahara so it was dynoed and the A/F was good. Motor comes back and it wont start. Go over everything and cant find any thing wrong. Re timed the cams, checked compression, replaces CDI. No luck. Put a 42 pilot in it and it started right up. sounded/felt a little rich so he kept playing with it. It is now down to a 38 pilot and the air/fuel screw all the way in and it still runs. Turn it out 2 turns and it is a little hard starting.
Why would there be such a huge difference and that Pilot is really small compared to the first time. Any idea what we can look for. Oh almost forgot it also has the R&D fuel bowl. I'm running a 42 pilot on my bike with no problems with the mods below. Dealer said the 38 is as small as the jets come. The pipe glows a bright red at idle whitch I know is OK not any more then when it did when it was stock.
Any one have an idea why the jet needs to be so small?