flat spot at 1/4 throttle opening

[Dave8338]

Lean on the pilot circuit. Stock air jets?

 

[tkent02]

Is it lean or rich when it is having this problem? Sounds like too lean.
Easy enough to try a different number of shims.
First, are the float levels adjusted correctly?
Are all of the jet sizes correct?

 

[dwfranke1]

all stock sizes and i dont know if the floats are set correctly

 

[tkent02]

That would be a good place to look.

 

[dwfranke1]

thanks for the suggestions, its off to bed and into the carbs in the morning, i will read up before starting to see if more help was offered

YOU GUYS ROCK

 

[dwfranke1]

can you send me a link to the procedure for setting the float level, i cant seem to find it and i know someone her has it, PLEASE

 

[tkent02]

Try Cliff's site. He has everything.

 

[teddux]

I saw this in a previous post:
http://www.iwt.com.au/mikunicarb.htm

I would put the needle BACK where it was.
What's your ALTITUDE?

 

[Guest]

Did you remove the plastic spacer over the clip on the jet needle and replace it with some washers aka shims?

 

[dwfranke1]

the plastic was replaced by the PO with 4 1mm washers

 

[dwfranke1]

i live at about 1000 feet and ride mostly between 700 and 5000 feet, i only know this because i have a GPS

 

[dwfranke1]

adding the 3rd washer to the needles seems to have done the trick
thank you

 

[Dave8338]

adding the 3rd washer to the needles seems to have done the trick
thank you

Lean FTW.

 

[Billy Ricks]

Lean FTW.

Yup, problems down low is usually a lean condition, up top rich.

 

[Guest]

Just as a baseline, the plastic spacers on my '81 750L carbs measured .100" (2.5mm). I raised the needles about .050" (1.25mm) to get rid of that flat spot, resulting in a spacer measuring .050".

Don't know if the E carbs are the same, but the PO's 4 -1mm spacers measure around .150" already. Try running 2 shims, that will essentialy raise your needles about .075". If that's too rich, try it with 3 shims...

 

[Nessism]

Two turns on the pilot screws is kind of lean too, that may be contributing to the problem.

 

[tkent02]

adding the 3rd washer to the needles seems to have done the trick
thank you

Hmm, adding the third washer above the clip would have pushed the needle down farther, made it leaner than it was, so if it runs better now it was too rich.
If this is the case add another, see what happens.

 

[Guest]

He was rich on the needle and leaned it by adding another washer.