No power on hills

[Reddeye]

'72 C20 with BBC and TH350. Last spring I removed the propane system installed in the early 80s and replaced the entire fuel system and installed a refurbed Q-Jet. Idles well but runs very rich and struggles to make it up hills. I thought the timing might've been adjusted for running on propane and found it was quite advanced. Once adjusted correctly it doesn't seem to be running as rich but I still have no power on hills. Any ideas?

[geezer#99]

What was the timing at with propane and what do you have it set at now?
Where in Utah do you live?

[Reddeye]

It was advanced something like 18 degrees.

I’m in North Salt Lake, right where it gets hilly

[geezer#99]

Should have left it there at 18.
At your elevation your carb runs rich. Think of it as same fuel, less air. You need to start the spark(flame) a bunch earlier.
What did the carb originally come off of?
You might need to adjust the secondary air door. It could be opening too soon adding more fuel you’re not able to use.
What’s your rpm when climbing the hills?

[Steeveedee]

Refurbished carb? Probably not jetted correctly for your altitude.

[YellowK5]

you will need to rejet the carb as posted above

[724jacks]

You didn’t say much about the distributor. I’m guessing it had to be adjusted to run on propane. All the carb manufactures say to have your timing correct before making carb adjustments. A good place to start for a stock engine would be 8-12 degrees initial, 34-36 degrees total all in by 3000-3500 rpm. Make sure the weights are moving freely and put in new points( if it has them) and your ignition is in good working order before moving ion to the carb.

The carb is probably rich and will require adjustment, since your elevation is about 4200’, but a “lazy” engine is a symptom of improper timing.
Posted via Mobile Device

[68 P.O.S.]

Get your timing straight before you adjust anything else. If your timing isn't right, nothing else will be. At that elevation, you'll probably need 38 degrees total timing (or more), but I wouldn't go any lower than 36. As Geezer said, 18 is probably good for your initial timing, but you're gonna have to play with it. You'll also need to get lighter advance springs in the distributor (Crane has great springs) so you can bring the "all-in" value to a reasonable 2500-3000 rpm. Then restrict the vacuum advance to provide ~10 degrees and hook it up to manifold vacuum.