OKO Carb Over Flow/Vent

[bulldogfallon]

Marc from Hot Quads ran across something that "may"be helpful for OKO carb users...

He found that the over flow (brass)tube in the float bowl may be blocked...

I pulled a new OKO off the shelf and my was clogged....Blowing from the brass tube to the outside of the carb

I cleared it out and it now can overflow properly

Now....This tube may also act as a vent much like the vent on a gas cap...

Any carb experts out there know if this will help them run better off the line....

We weren't sure if it was a vacuum issue that this blockage was causing???

[ecmini1]

The vent being clogged will slow down fuel into bowl. The only time this will be a big problem is extended wide open throttle due to fuel wont flow fast enough to keep up with the demand. If the machine has the bogg then takes off hard it has fuel in the bowl and the vent is not the issue. If it boggs and wont accell then it could be to slow fuel supply. In some modified eng. we have had to add a vent due to loss of pwr on long wide open throttle.
Hope this helps. Sometime its easier said than typed.

[bulldogfallon]

I have noticed that the OKOs don't perform well at wide open throttle.....after a little more than 3/4 throttle they seem to flat line a little..

Even when jetting up and down it doesn't go away....

This could be the problem then?

The answer to why I couldn't get the main jet right?

I would change jets up and down and not be able to get it right on the way it should be.....

hhhmmmmmm........

[dblacks]

just checked mine and the vent works fine

[wrhracing]

The carb works on pressure differences. If a vent is plugged then the bowl will not be able to establish flow thru main jet etc.
The carb venturi or throat creates lower pressure then what is in the float bowl hence the fuel in the float bowl now considers itself at a higher pressure so it exits thru jets or passageways to the low pressure areas. ( Your engine gets fuel to burn.)
How do you fix the bog after landing from a jump? Add more vents to the carb. It's the fuel bouncing up and temporarily plugging the vents.

[wrhracing]

Originally posted by bulldogfallon
I have noticed that the OKOs don't perform well at wide open throttle.....after a little more than 3/4 throttle they seem to flat line a little..

Even when jetting up and down it doesn't go away....

This could be the problem then?

The answer to why I couldn't get the main jet right?

I would change jets up and down and not be able to get it right on the way it should be.....

hhhmmmmmm........

Gary send me one each of both carbs, and I can measure the flow for you. I suspect one flows better than the other. I used to know the exact numbers on all of the carbs but it's been a year or two since I did the research.