AngryShawn

I've been lurking here a bit reading the wealth of info and wanted to get the advice of those who have gone before me prior to messing with my carb any more that the full disassembly, inspection, full passage blow through with compressed air and reassembly I just did.
Here are the important details:

04 FS450E - box stock - currently set up for supermotard, but my dirt wheels are on the way - total riding time consists of about 4 track days (I'm a total n00b), approx 6-8 hrs on the motor since new, thats it!

Current jetting specs are bone stock:
178 main jet
40 idle jet
obdvt needle
clip in 2nd position from top
85 starting jet
200 main air jet
100 idle air jet
fuel screw 2.5 turns out

Riding conditions: SF Bay area tracks and soon to be off road in the 1000-4000 ft range.

The issue(s): hard starting, seems to run fine while choked, dies immediately when taken off choke. If you maintain throttle while turning off the choke it runs but VERY poorly (backfiring, wanting to die, feels very 'surgey' when riding - almost like its running out of gas) however when it warms up it seems to run pretty well.

My suspicion is that the pilot circuit needs to be richened up a bit, I'm thinking of trying two sizes larger to start, unless I should make a bigger jump? Sounds like I would also benefit from moving to a different needle taper like the OCDVR, but that would come after getting the bike to start easily, haha.

Any guidance is most appreciated, I'm itching to get this bike set up properly!

husabutt

Try using the 2005 closed course jetting which is similar to what you have except use the:

OBDVR needle 6th position from the top

Fuel screw 2 turns out

Taffy

you are hopelessly rich:

178 main jet - a 160MJ or even at your altitude a 155 wouldn't go amiss
40 idle jet - this is correct
obdvt needle - the dvR or a DMS from yamaha - loook in the doc for the code
clip in 2nd position from top - adjust to suit but start in 4
85 starting jet - perfic!
200 main air jet - it'll do
100 idle air jet - far too big, get a 60 or better still by the adjustable screw from sudco
fuel screw 2.5 turns out - adjust to suit.

regards

Taffy

husaracer

I have a '05 fc450 and it starts great at first kick it runs fine untill you hit the throthle then it dies completely.
When I open the throthle slowly its fine it revs up like hell.
But when you swing it full open it does bhooooooaaaaaaaaaph........
I tried to set up rich and lean nothing helps.
The carburator is set up now as stock en the screw is 2.5 turns open.

Has someone advice it must be something simple in the carb.




Sorry for my english.

Taffy

drop the needle TWICE

cured

Taffy

AngryShawn

Figuratively, yes, I like to think so
Monetarily, far from it
Thanks for the input, I've ordered the parts from sudco and they should be here before Friday so I can terrorize the neighbors over the weekend, haha.

AngryShawn

I owe you a pint Taffy, the bike has come alive with your suggested jetting.
I only took two WOT runs through the neighborhood as to not anger the neighbors or draw the cops, but roll on power wheelies were happening in abundance
I'm off to the track or trails as soon as possible to enjoy the 'new' bike.

Taffy

well done shawn!

so what did you do? just the MJ?

regards

Taffy

AngryShawn

I went the whole route:
Adjustable Idle Jet from sudco
OCDMS needle - started in 4th position but moved to 2nd
155 main (and 160 for good measure in case I needed to tune further)
Fuel screw 2 turns out (for now)
Taking it to the track on Christmas Eve for a full workout

Taffy

i wondeer if dan, daleO, eric et al are reading this?

20 minutes work, two test runs, no moaning just "it works!".

for your info shawn i've been tirelessly told that you can't jet american bikes like this due to your 'special fuel' and 'special weather'!

in the meantime the anzacs and 'we' (the royal 'we' on this occasion arf! arf!) are running these low numbers.

regards

Taffy