706 question

Farmall 706

New User
I checked the compression on my 63' 706 c-263 gas 90 psi on 1,2,3,6. But 0 psi 4&5. Where do i go from here? I also noted a oil/gas slick under exhaust manifold on 4&5 .
 
Probably have a head gasket blown between
4&5. Seems like 90 is a bit low for the
rest, but maybe I'm wrong.
 
As noted a head gasket. The 90 PSI on the remaining might be the method used, or the gauge. Was the throttle wide open for the
tests, was the battery nice and charged, Were the plugs out, and did it compress 10 revolutions (5 compression strokes) on each
test? If not those are OK. If yoe they are low.
 
I pulled the coil off,then one plug at a time,cold motor with the charger on battery turned over 5 to 6 cranks. I have never done this before,rented a gage from autozone.
 
As others noted head gasket first but also probably the valves. I did a 560 with the same engine last year and you could see the valve seats through the valves when I got it apart. Ended up with sleeves and
pistons too. The head was good and the gasket was ok also. Did you squirt oil in to see if the rings are good on each after the first try to check the rings? Splitting the tractor is almost easier if you need
to take the head off. The gas tank has to be lifted to get the pushrods out easy.
Roger and good luck
 
No didn't know about adding oil. It was running fine then sounding like a miss. Puffs a little white smoke at start up. I have no way of splitting I'll take all apart.
 
Do a search on wet compression testing to check the rings; I do not remember how much oil you use , I do not think much , if the pistons and rings are worn the compression test will be better. I have never really did it because I usually had it all the way apart by then. Common thought was if you rebuilt the head then the bottom would use significantly more oil if weak and then end up finishing the overhaul.
 
To diagnose a bit further before pulling the head, you could back the rocker arms off on 4 and 5 so valves are completely shut, then put air from your air hose into cylinder 4 and see where it
comes out at. It will likely blow out of number 5 plug hole, but also listen at exhaust, carb, radiator cap, and dipstick tube.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top