Carb masters: 3rd gen still will not idle on pilot circuit with butterflys closed. Flooding into cyl

40 slow jet

Looks correct...

 

I have pilot jets from a 96. They are marked 40S. They have one less cross hole drilled. Not in a hurry to fuss with jetting. Wise to mess with dat or not? All my floats have been quadruple checked, all are set to 9mm. This might be the tail chaser that let the previous owner to sell it...But NOT me! Quitting now would make my voyage thru hells gate in vain :crazy:

 

Hey Tinkerin...all my inlet needle seats have crushwashers installed. Been there since I have owned the bike. Is this absolutely necessary? I thought it to be a good idea. That might be variable also..

 

My main girl..a thing? Totally butt hurt :wink: Fuel pump is from a 96 VFR750. Same 900cc flow, correct? (please be the problem)

 

would a bad fuel relay be an issue in this mix? *hmm...nix that idea.

 

Here is a thought... is your fuel pump (3rd gens have a pump right?) providing too much pressure and overfilling the float bowls? If it has a pump, bypass it and run it without a pump. It should fuel lfine down to about 1/2 tank.

Edit... tinkerin beat me to it...

 

Next time you pull the carbs try setting the float level to ~14mm and see if that helps. Even though the book says 9mm, you have a lot of nonstandard parts and the 96 pump, so maybe use the 96 float level. It should reduce the flooding issue and will bias all the fuel circuits toward the lean side.

What do your mixture screw tips look like anyway?

i have a 96 that is running 42 pilot jets--it does run on the rich side in Summer (no choke to start), but it will idle properly. The mixture screws allow adjustment over a range of at least +/- 1 pilot step size or more. If the screw tips are not damaged that is...

The CBR900RR use a #40 pilot, but it is regular 40. That 40S is a special for the 4th gen VFR, and the number and size of the cross drilled holes in the emulsion tube is a critical factor is the mixture. Smaller diameter or fewer cross holes means less air in the emulsion => richer mixture. All the more reason to raise your float level and decrease the amount of fuel in the bowls.

 

Copy that. Remember the small bore above the enrichment circuit fuel jet I asked you about? There is a plug in the bowl wall across from it per your pic. My fuel level is approx the yellow line. Is this ballpark?

 

I had wondered the same. I will add gravity feed to the to do list...

 

My mix screw tips look exactly like the good ones in this(your?) pic. Not pointed. Flat or perpendicular to the screw.

 

Lower it is. Hints tinkerin?

 

Hell no, that is flood stage! But you have found the culprit...

Don't doubt yourself tinkerin, that is a GOOFY line. The fuel level should be deep into the bowl, not up into the body. The floats ride on the top of the fuel, so the bottom of the float (the setting point) is where the fuel will be in the bowl.

BTW i see you have the same need for a magnifying glass that i do, it's always sitting right there on the bench within reach...

 

Yes my method is similar. Credit card tool.