Will not pull hill

I have a 62 cj5 with a rebuild F134 Carter yf carb I get 17 hg. vacuum everything seems to be working fine
But I can not get it to pull up about a 25% grade in first gear hi. I rebuilt the carb retarded the timing. It starts rite up runs fine
The first time after I Retard the timing the rpms went to 800 and the vacuum holds steady at 18 hg It pull the hill the second time I had
to put it in low. Any thouts

 

I would advance the timing a little at a time and try it....

 

25% grade is pretty steep. Means you are going up 25 feet for every 100 feet you are going forward.

That steep you might want to stick to 4wd low range.

Locating and putting on the heavy flywheel may also help.

Don't overdrive your own abilities. you may want to find a slope with a different (lower) angle on it.

 

Just for laughs, check the compression of the engine.

 

OK everything checks out on the engine vacuum, compression , timing, carburetor. Still no luck! It will pull the hill in revers with no problem. But not in first gear. Some one said its the transfer case. Is this possible. I would like to know before I take it all down again. Any help would be appreciated

 

Not sure if this would help but is worth looking into.

You said you rebuilt your carb, but did you do anything to ignition? Like what's your condition of your points.

I know you changed timing.

 

Points, plugs, condenser, rotor, cap, wires all new

 

As noted in post #3, 25% is steep-damn steep for any sort of normal road, few of which you will ever find steeper than something around 12%.

Being a 1962, you probably still have the T90A with a 2.79:1 first gear. Reverse is 3.79:1 which explains why it goes up backward. If you had the t90C with the 3.34:1 first, you would likely be fine. What are you getting for top end on a flat road?

 

The above comments about the lower gear ratio in reverse is correct, and may very well be the answer.

However, since you rebuilt the carb, this makes me think there may be an issue with the float level.

I do have to admit that I am not familiar with the carb in question, but a difference in performance when the front of the vehicle is up or down is often a float level issue.

 

So is it dieing out when you head up the hill?
You are very effectively putting your fuel pump higher than you gas tank doing this. And starving your engine out.. Just choose a different rout. No sense in tearing up your equipment. Unless you are made of money, then go ahead.

Are you doing this in first gear high two/four wheel drive or are you trying it in low range? How long is this hill?
Personally I think you are just overdoing things.

 

Hill is my driveway it,s 250 ft.long dirt road and it is steep When I try to come up it bogs down like you are trying to start out in to hi of gear whether I start out at the bottom and get a running start or in the middle standing still . this only happens in two wheel hi it will come up in four wheel low with out the hubs being locked in . I have not try in four wheel Hi. Do you think I should try to find a four speed with a lower first gear

 

Just use low range - that's what it is for.

 

That will likely start the cascade of modifications. A T98 would certainly cure the problem but so would a T90C if there isn't one of those already in there. The T90C would be a straight bolt-in or you could just find the T90C gears and use your existing case and most of the remaining parts. The T98 will require drivshaft mods and a few other changes to fit it unless you can find a rolling chassie to swap all the corresponding pieces.

 

I agree with this too. Retard the timing lowers the power.

 

"Retard the timing lowers the power."

Yes and no. It will increase torque at low rpms.

 

25% grade with 74 hp and a 2.79 first gear.......use low range.

 

rebuilding my backup T90 it is a C I counted the teeth my self. I have not check if the one in the jeep is a t90a or not when I rebuilt it the first time but I am petty positive it is because it came out of the 62 my backup is out of a 66. So when I get it rebuilt and in I will know if that was the problem. Will know in a couple of weeks wish me luck
:?

Also Retard the timing increased the vacuum all most 2 Hg and the Rpms100. I had to back the crab down a Little