Carter YF question

[yodabiri]

I put a carter yf 1 bbl carb on my 250 engine in my 65 mustang and ran into some small problems. The carb started fine and took a few minutes to idle down properly without stalling) probably because it has been sitting for a couple of years). It is able to idle, but it surges from 750rpm to 1200rpm and then back down to 750. What could be causing this to happen? I have all of the numerous vacuum ports plugged, so Im pretty sure there are no vacuum leaks. Could it be some kind of blockage in an idle port or something? (sorry if I sound like I have no clue, I havent worked with this carb yet) Also the idle of the YF is quite rough, where as the autolite 1100 ( I fabricated a special adapter plate to put the 1100 onto the 250 engine, so that I could have a reference to get the engine running) I took off had a fairly smooth idle. I tried nearly every possible approach short of rebuilding the carburetor. If this helps any, the iginition is a DUI with a ~0.052 in spark plug gap. Thank you in advance.


yoda

 

[1965fastback]

Sounds like you need to open the carb up and clean it good. A rebuild would also help.

 

[yodabiri]

I kinda thought so. What could be causing the surging at idle though? The carb does idle and has decent throttle response, but the idle fluctuations are strange.

Thanks for the response.

 

[1965fastback]

Dirty idle passages could do it. Flush it out with carb cleaner and see if it improves any. Might be idle mixture too lean/rich.

 

[yodabiri]

I decided to drop the idea of the carter and put the 2300 holley 350 cfm carb on with an adapter. The difference was huge! The car didnt gain much in the bottom end, but the higher RPMs are so much more fun now! I will have a couple of pics of my current setup posted in a little while.