Little change in mixture with idle screws fully seated

[springl]

Hi everybody!

I have an 1986 P30 chassis motor home with a 454, California engine. The Q jet carb number is 17085212. I rebuilt the carb and when reinstalled the idle screws need to be clear in. Prior to rebuild the engine idled when screws were about 3 turns out. I have installed an wide band air/fuel meter and the a/f mixture is around 10.6 - 11 at idle with the screws clear in. The engine idles ok and looking down the primaries there is no noticable fuel coming in above the throttle plates. The throttle plates appear to be closed and if the idle speed screw is backed off fully the engine will die. I have tweeked the timing to no avail. What did I do wrong while rebuilding this carb?

[77cruiser]

How high is the float level?

[springl]

The carb kit instructions said 3/8 and so I used that

[Cliff Ruggles]

Did you get one of our kits?.....Cliff

[springl]

Just finished installing the new kit supplied by Cliff. The idle screws now work properly. The A/F meter says about 13 at idle. Cruising the A/F mixture is about 16. Under acceleration it drops to about 12.8 whether using primaries only or opening the secondaries. I now know where to go for any Qjet needs. Motor home carbs are (were) difficult to get proper parts for.
Thank you Cliff and Staff.

Linn Spring
Vancouver Washington

[Cliff Ruggles]

Good news!  The motorhome carburetors require the correct parts or they will not work correctly as you found out.  Lots of folks don't realize this, glad we could help out.....Cliff