Raider was running fine for the last couple of months since I installed the Weber carb, but yesterday evening and this morning when shifting into 4th and 5th gear, it felt like I was trying to drive into a 100mph head wind.
Previously have installed rebuilt 5sp transmission, replaced plugs and wires, and changed all gear fluids (diff,transmission, and transfer case.
Any ideas as to what may be causing this lack of power in the higher gears?
Thanks

At what speeds are you shifting into 4th and 5th?

Is the choke on? Are you going up a hill? Good compression? Mechanical and vacuum advances working? Plugged catalytic convertor? Towing?

Usually around 35mph to 4th. Generally falls like this... 1st 0-15, 2nd 15-25, 3rd 25-35, then 4th. Around town, where most of my driving is (no interstate) is max 45-50, so I stay in 4th, seldom go to 5th. Tach is inconsistent so I can't really say what rpm, but the upshifts are probably 2500-3000.

Thanks

Not unreasonable speeds to shift at. Fuel pump diaphragm may not be holding pressure.

By choke on, do you mean is it stuck? Don't think so because it was warmed up and running fine in 1st-3rd. It did bind and stick closed once after the install, but would not start and stay running until manually released. I will check first thing in the AM.
Traveling on level ground, paved and not towing.
No cat, removed by previous owner. Just a "glasspack" type muffler and pipe exiting out back at normal location.
Not sure about compression.
Is the vacuum advance controlled by the vacuum line running from Weber to distributor? If so, previous looks at the vacuum line seem good, but I'll check tomorrow.

Thanks

Is there a way to check this?
Thanks

Checked the choke on the Weber carb and it is not closed. I went ahead and replaced the vacuum line from the carb to distributor; but the one that was there did look fine.
Ran the vehicle for 15-20 minutes in driveway and ran smooth, no missing. Took it our for a drive and initially seemed OK in 4th, but when you really give it throttle, no response, even bogs down and backfired a couple of times.
Could this be carb related. Have had the Weber on for at 2-3 months and never really experienced this before recently. However, mostly used to work and back where I never had to get down on the accelerator (like when passing). I adjusted the idle speed and idle mix on the Weber, but that's all the adjustments; not very versed in adjusting carburators.
Any thoughts ro suggestions?
Thanks

Double check timing and when that's O.K., be suspicious of the fuel pump.

They start at $17.09 plus shipping at (link) Rock Auto.

John B.

you can pick up a universal electric fuel pump for carbs cheep at napa, advance etc... I would try that.

I'm glad I don't have to deal with carb problems any more <img src="/forums/images/graemlins/nana.gif" alt="" />