problem with carbs and diaphrams

[madmaze]

ohh damn those are much cheaper =)
Thanks

[Houdini]

madmaze,

Your initial description started out sounding like you had a problem getting the "little engine that could" to IDLE correctly.

Somehow through this message traffic it morphed into a high speed, on the freeway, not running right on the top end throttle response, main jet issue.

You may want to put into words at what throttle position or operating condition the engine seems like it "runs out of gas" (most common) or sputters / backfires (less common).

Houdini (back again)

[madmaze]

Well actually it doesnt run at all at this moment.
I think it is because it doesnt get enough fuel.
which makes sense since i just got rid of my air box and replaced it with pod filters.

So im hopeing that bigger main jets will solve the problem.
any other suggestions?

[Houdini]

Look at Figure 7 of this link: http://www.iwt.com.au/mikunicarb.htm

You said it ran (probably like it was about to run out of gas) when a screw driver was in the slide taking it to something like 1/4 throttle...

From the figure you by-passed the idle circuit and started on the needle jet circuit... probably means you need to richen up the idle circuit several larger sizes of the idle jet and most likely raise the slide needle either 2 notches, to start, or add a couple .023 washers under the needle clip if no adjustment possible.

Sudco sells individual parts pilot jets, washers, etc.

What a lot of folks have suggested, because the 450 is sensitive to inlet side changes, is to return to the stock airbox to avoid having to fuss with rejetting the carbs (KISS)...not sure if you indicated what your compelling reason was for pods.

Last year some fine folks here helped me get my bike tuned nearly perfectly (using stock airbox / cleaner) here was my results:

http://www.thegsresources.com/_forum/showthread.php?t=126350&page=2

Do a search on Mikuni carb tuning guide...and take your time figuring out the conditions / symptoms 1 at a time...and keep the GS group informed.

[madmaze]

Thank you for all that information.
My reason for switching to pods was that my airbox had mice it in and a crack.
So instead of getting another one i just put pods on.

My pilot jets are plugged since that is how they were when i got them.
I will try to mess with the needle and i have bigger main jets coming in the mail.

I dont have time until this weekend to work on it, so then ill report back if and how it runs.

[Steve]

My pilot jets are plugged since that is how they were when i got them.
I will try to mess with the needle and i have bigger main jets coming in the mail.

Your pilot jets are plugged and you wonder why it won't start?

Let me give you a clue: messing with the needles and installing larger mains ain't gonna help.

I don't know how many times we have to say it for some of the new guys ...

CLEAN THE CARBURETORS

Follow the carb cleaning series, do not take shortcuts, do not pass GO, do not collect $200.
Every shortcut you take is one more reason you will have to come back and DO IT OVER.

In your original post you said "Ive spent way too much time on this ...", so just drop back five yards and DON'T PUNT. A proper cleaning of the carbs will take you several days, as you only do one each day, but before the one-week mark, you should be out enjoying your bike, unless you keep taking shortcuts.

.

[madmaze]

THE CARBS ARE CLEANED..
Plugged as in Rubber plug.