no power/pickup at low speed

My 225 has fairly slow pickup at low speeds.It has HEI at 5 deg before, automatic trans. and 3.73 gears. Vacuum guage readings of 7-10 pounds at idle to 1000 and fluttering guage needle(carb and manifold checked). What to do?

Josh

 

The usual-
Get fresh gasoline-- highest octane
Clean/replace the fuel filter, and Clean the carb.
Check compression
Check spark
Change spark plugs and wires

Try different timing

Check to see if the timing chain in good shape-- listen for slap noise.


and all that Jazz

 

Gas-last week
plug wires-2 months
carb-reman last winter
timing chain+gears-last winter
compression-last fall-around 100 lowest, 115 highest
air+fuel filter within last year, air filter looks clean

It does have decent power once the RPM's get going, just no umph getting started.

 

vac advance ?
is it working?
hooked up properly ?

 

maybe you got a bananna in the tail pipe!!!R) R) R) R) R)

 

vac reading at idle way too low
unless you are on top of Mt Everest
cam ? good question

 

sounds like a vacuum leak to me. when the :v6: is running, LIGHTLY spray some carb cleaner around the carb. IF the :v6: speeds up a leak is present.

 

Maybe it's an Fhead!

 

I second the motion to check that the vacuum advance is working. -the timing needs to be retarded for low rpm power acceleration.

The very (too) low vacuum readings ought to be keeping the timing retarded though, maybe too much? Why so low, and why fluttering? Sticking valves? Or is timing *way* off?

Intake leaks may tend to show up as stumbling under quick acceleration/load.

Possibly try dialing the distributor timing up and down a little and see what happens.

Pete

 

Cam chain off 1 tooth?

 

The fluttering and low vacuum reading is a sign that something is wrong. You could have valves hanging open or a vacuum leak. If the engine was recently rebuilt, someone could have put pushrods in it that are too long and aren't letting the valves close completely.

 

I've ordered new intake manifold gaskets and will probably get them/intall tomorrow. It is a new timing chain and gears. It seemed to work fine after I installed those. The gaskets were from PO. If I install those and can't find any other vac leaks I guess my next step will be to check the timing/ vacuum advance again.

Josh