How do i LOWER the k/ph on a sync tool / carbs

[audiocontr]

Both Jim and Dennis have stated that the ideal k/ph of both carbs should be less than 10. Jim 6-8 and Dennis at 9.

With my idle screws all the way out and linkages disconnected, The lowest I can get is to 14. I have timing at 5 BTDC to get the idle at 900. External screws are at 1.5 turns out

The sync tool is from Scott and I have the side holes closed off.

This tells me that im pulling too much air correct? Are there any adjustments i can make before i assume damaged butterflies and/or shaft?

It idles well as is but stumbles on initial acceleration

[berger]

Could there be air leaks elsewhere in the carb?


Sent from my Mobile

[krick3tt]

When I rebuilt the carbs I honed the surfaces. Makes them very flat. They were not totally flat before and I am sure that is where some air got in and some gas out.
Now the only smell of gas is from the inlet to the tank, will work on that next.

[audiocontr]

Ill try starter fluid around the gaskets, but i suspect they are pretty good. They are brand new and applied to a clean surface

[Jim LaGuardia]

I would suspect a bent shaft , especially if it is a brass shaft. I find twisted throttle shafts on a majority of the brass shaft carbs I see. The engine should not run if the idle stop screws are backed off . Pictures of the components might help.

[audiocontr]

Thanks Jim.

These are no longer brass, but the aftermarket from SAV. The point that the engine should not run with the idle screws out tells me the most. I still have something amiss with the carb bases.

Might be time to order new shafts and butterflies to know for sure

[Stekay]

Can we assume you have your throttle linkage removed?

[audiocontr]

Yup yup.

[Jimm391730]

The carb balancer tool is used to get the airflow through both carbs equal at idle; that is all it does. The exact reading is not important (but significant differences compared to other trucks point out other problems). Since the Pinz has two separate carbs, it is possible (almost inevitable) that the idle airflow through them will be different. Assuming everything else is working properly, balance is one of the last steps.

But since your readings are significantly higher than "normal", we can conclude that your engine needs to flow more air than expected. What could cause this? If there were other vacuum leaks, the engine would be getting more air, but NOT through the balancer meter; if this was the case, the meter would read LOW. But vacuum leaks lean out the mixture so the butterflies might need to be open further to get enough fuel (and addtional air) just to keep running (but vacuum leaks typically just raise the idle rpm). Or your carbs are out of whack, for example, if the float level is too low it might not get enough fuel until the butterflies are opened more than "normal". Ignition timing can cause the engine to idle with less power, so the butterflies would need to be opened further just to maintain a normal idle speed. Valve lash could be too tight/too loose, on all or just one valve or cylinder, also messing up the idle. How about the idle solenoids -- are they working properly? Is the "choke" (actually, the mixture adjustment) in the proper postion?

So you can see that there are alot of other issues that will mess up the idle, resulting in "bad" balancing readings. As the balance is one of the last things to adjust you need to go through everything else first and ensure that these items are OK, before worrying about the balance. If only the butterflies were out of whack/not closing the carb bores properly (and everything else was OK) then you would have a very high idle speed that could not be reduced. Since your idle rpm is at 900 I would suspect something else is wrong -- float level, or something else other than the carbs or vacuum leaks.

[audiocontr]

Excellent response and I appreciate it. Here are a couple variables that I think cover your questions:

The engine continues to idle with the idle screws all the way out. This means vacuum leak or messed up butterflies/shaft.

The idle speed can be altered by the timing. With the idles screws all the way out, lowering timing to 3 degrees will still the engine. Raise it to 8 degrees and my idle speed gets into the 1100 range.

Still leads me to think its a butterfly sealing issue.

Solenoids are good
Float levels are good

[edzz]

The engine should not run if the idle stop screws are backed off . Pictures of the components might help.

:idea: As Jim said.

[audiocontr]

Ill grab some photos today.

I had a thought - Is my mixture too high? Instead of 1.5 turns, maybe start at .75 turns of the mixture screws? I know the truck will stall if i screw in any 1 of the 4 mixture screws fully.

[M Wehrman]

I've seen mis-adjusted accel pump rods not allow throttle to close completely. Just my .02 4 U!
Mark

[krick3tt]

If the end clips on your throttle rods are a bit loose on the ball it will throw things off. Get new ones. They are very inexpensive for the benefit they will provide.
Get a few extra for future use.

http://www.pinzgauer.com/showdetails.ph ... o=9014708/

[audiocontr]

I've seen mis-adjusted accel pump rods not allow throttle to close completely. Just my .02 4 U!
Mark

interesting. I will try to disconnect and check for variance.