1985 720 ST help.

[Rat720]

Hey everyone. Just picked up my 7th 720. It's a 85 st extended cab. Automatic trans.

This is my first automatic one and was wondering if its normal for it to be this SLOW!!!?! It has a weber and I'm in the process of tuning it a bit better but it runs fine other than a flat spot right off idle, (any ideas) but its just extremely slow compared to the 5 speeds I'm used to. I plan on swapping in a 5 speed when the auto craps out but I hope that will at least be till near the end of summer.

It shifts perfect just feels like it has no power.

 

Also if anyone has a dipstick for this trans I very much so need one. So please let me know.

Thanks

[DREWSDIME]

Yes auto's are slow, I have an 85 xtra cab with auto and its very slow. I did not realize how slow it was until I rode in my friends with 5 speed. Good for cruising and freeway driving if you like doing 65-70mph

[slemers]

Several guys I have talked to have flat spots off of idle. My 720 has it also if I set the timing @factory specs. When I bought the truck the PO had a bolt crammed into the vacumn advance line and had the timing set to 12 degrees BTDC. It didn't have the hesitation set up this way, but I am now running 5 degrees BTDC and it runs fine except for the occasional stumble below 1500 rpm or so.

[SHORTDOG]

Let's see pics!    :thumbup:

[ryanw1]

I also have an auto and it is much much slower than my 5 speed, But I dont have these "flat spots".

[bryant2482]

i had the 3 speed auto in mine. its shifted great but shifted way too soon. by the time i got to 25 mph it was already in 3rd. i dumped it and went with the 5 speed. much better!!

[datzenmike]

The up shift is dependent on engine load and will up shift instantly where if you had a standard you could let up on the gas and cruise along in second or third and shift when YOU feel like it. It's a dumb machine and only follows a governor and shift modulator kind of logic. My 710 goes into second within a car length at light throttle and warmed up and you don't even notice it. But if you floor it from the start it goes pretty good and second is a hard bang into gear.

Several guys I have talked to have flat spots off of idle. My 720 has it also if I set the timing @factory specs. When I bought the truck the PO had a bolt crammed into the vacumn advance line and had the timing set to 12 degrees BTDC. It didn't have the hesitation set up this way, but I am now running 5 degrees BTDC and it runs fine except for the occasional stumble below 1500 rpm or so.

Correct timing is 3 degrees. Flat spots above idle are likely a worn out accelerator pump. This is particularly noticeable on an automatic.