Carter yf 2100 ---- bog off idle

[dennislbrooks]

I have eliminated the ignition, timing, valve operation, fuel, float level and all vaccuum leaks. I have rebuilt the carb and cleaned every port , jet, etc. The squirter works. I have pulled it off twice and double checked the build. The ports on the bottom are both exposed to vaccum.

It starts and idles exceptionally well. Timing is set about 5 btdc. The advance works -checked with timing light. All plugs are firing. New HEI.

I believe the bog may be from shaft wear or carb is somehow not suited for a 235.

Anyone have any ideas of what I can further check. Or who can fix the throttle butterfly shaft clearance?

[geezer#99]

Bump your timing up to 12 initial.

[dennislbrooks]

Geezer#99, Plugged vaccuum then I set the timing at about 10 btdc, reconnected vaccuum and it helped but still some there. 15btdc did not make any more difference.

I have a little play in the throttle shaft. I will remove and check for wear. The base is cast steel or iron --should be little if any wear. Maybe I can get by with a new shaft. The hole in the base new is 5/16"- .3125. The shaft new is .309".

This carb is on a 1954 hydraulic lifter 235 in a 1946 3/4 ton. Seems to be a good engine

Ok, the shaft shows little or no wear --steel -- and does measure at .309. The wear is in the base and measures as good as I can measure about a little less than .313.

But first I am going to lean the mixture screw and increase the idle screw.

thanks for the response.

[dennislbrooks]

Best I could do on it was lean the idle mixture screw some --- a little rougher idle and then increase the idle screw to about 550 rpm. I am running 10 btdc initial advance. This took most of the tip in hesitation out.

I will never get my wife to ride with me in this 1946 3/4 ton. Those straight cut gears in the crashbox 4 speed make some noise. I figure 40 mph will be top speed for me in it.

[geezer#99]

Could be that tip in was and always be there.
Likely wasn’t a concern from when that motor was new.
Just the nature of the beast.
40 mph, eh!
Buddy of mine had a 50 gmc with a 216 and a 6.13 rear gear. Top speed was close to that.
Great truck for hauling firewood though.

Did you supply a full 12v to the new hei?

[dennislbrooks]

Yea, full 12 volts, the engine does run pretty good and is quiet with the hydraulic lifters . It will go faster as I have a 14 bolt in rear with 3.73 gears -- just the gear noise and the straigh frontt axle plus drum brakes.. I do have a good sm420 that probably would make it quieter plus 2-4 sychros. I will have to investigate what it takes to make the switch.