my 223 I-6 shakes a little bit when it is running. is this bad motor mounts or normal. i'm not much of a mechanic so i'm not sure.

travis
64 f100 stepside
65 f100 styleisde

 

From what I've seen those old inline sixes with a carb
tended to idle a little rough. It's hard to say without
seeing it, though. If you want to check your motor mounts,
have someone put your truck in gear with the brakes on
and the engine at an idle and watch the mounts for freeplay.
Shift it back and forth from first to reverse, it's a
standard transmission, just slip the clutch and load up
the engine a little. I hope this helps! Tim

 

Probably not bad motor mounts, but not normal either. The engine should idle dead smooth, even smoother than a V8. You may have a slight misfire on one or more cylinders.

If it doesn't smooth out as you increase RPM, it may be something out of balance, i.e., flywheel.

Good luck,
Dan

 

it does smooth out at higher rpms.

travis

 

 

You could try checking the points or see if you have a vacuum leak somewhere. A vacuum leak would cause it to idle rough and smooth out at higher rpm's

 

hey man, ive had several trucks with this engine and ive always heard that these "low compression" engines never do idle very smoothly, but they smooth out nicely when running down the road. thats not saying that you dont need to check your engine mounts, its just not uncommon for them to run that way......

 

Sounds like it just needs a little TLC. If it hasn't been recently tuned up get some points and a condenser. Better than that would be a Pretronix electronic set up. About $60 I think and I've heard nothing but good things about them. I've still got points and when they're gone ....

Look your plug wires over real good. If they're real bad you can see arcing at night and if they're doing that they definitely need to be replaced.

I don't know what kind of carb you have but chances are it's a fairly simple rebuild. Get a kit and a gallon of carb cleaner. Strip it and soak the body in the cleaner overnight, wash it with hot water after, blow it dry, and reassemble. You'll need to reset the float with the new needle and seat but there's usually a thing in the kit for it.
Make sure the accel pump squirts as soon as you crack the throttle. You should probably plum every hole in the thing to familiarize yourself with goes on where.
One thing that doesn't come in the kit ocassionally comes up with old carbs. The throttle shaft runs in bushings and after many years of use play can develop to the point of an intake leak. Sucks the air right thru but any competent carb shop can fix that for you.

Again I don't know your motor but a lot of old Sixes had solid lifters that need ocassional adjustment. A factory manual detailing the procedure is probably available on this website.

Compression testing is relatively simple and good to know. Look for all 6 to be within 10% of each other. Hold the throttle wide open and turn it over until it don't go up no more.

If you cover all that I bet it'll run real sweet.