FJ1200 carb spitting

[km4hr]

...
Like several people suggested I feel the carbs are too lean. But I don't know how to make them richer. ...

Did you check the float height on the spitters?  angle of the dangle and all that..

Is it possible that the fuel level in the bowls is correct at idle but not under load?

I've "cleaned" the carbs 5 or 6 times now, but I have not yet removed the floats and cleaned the needle valves. Could it be that the needle valves are partially plugged, allowing enough fuel for perfect idle but not enough to operate under load?

Also, the fuel pump seems to make plenty of pressure with the engine off. It spews out when I loosen the hose clamp at the carb. Do I need to measure the fuel pressure with a gage while the engine is running. How much pressure should there be?

The reason I haven't cleaned the needle valves is because it's hard to remove the floats. The carbs can be cleaned almost entirely without separating them from each other. But removing the float pins without separating the carbs is tough. I tried, it ain't easy. Separating the carbs seems like a pretty major operation. Is there another way?

Maybe I should open the bowl drains with the engine off and see how much flow I'm getting? If it just drips out then that's a problem right? There should be steady flow even after the bowls are empty, right?

I'm scared of the fuel supply system in this vehicle (Legends race car). It's electric fuel pump runs constantly. There's no low pressure cut off as far as I can tell. I'm afraid of getting a fire started with no way to shut the gas off. For that reason I don't want to do the bowl level test  described in the Clymer's repair manual. That procedure involves attaching clear U-tubes to the bowl drains so you can view the level with the engine running. But if gas spills out of the tubes and a fire starts I might not be able to get to the ignition switch to shut it off. The procedure also requires removal of the carbs many times, not practical at all.


In summary, there is a possibility that the fuel flow is restricted inside the carbs between the fuel line attachment fitting and the needle valves. Is there an easy way to test this?

Sorry about the long post.

thanks!

[SlowOldGuy]

Usually spitting indicates a lean condition, or a bad plug or plug wire.

If you can get the float bowls off, then removing the floats is easy.  You do not need to separate the carbs to remove the float pins and floats.  If it sat for any period of time (any probably even if it didn't) the filter screens on the end of the needle seat could be covered with old fuel gunk or other trash causing a restriction to fuel flow.

You have to remove the needle seat to get to the filter screen.  Replace the needle seat o-rings while you're in there.

DavidR.