ArmySoldier

I just did a compression test on my 12A engine, I have 6 kg/psi on T1 and 4 kg/psi on T2. I know the max difference limit is 1.5 kg/psi, so... has anyone ever had a difference of 2 and still had a tunable engine? .... or is my engine shot? It runs rough 'like' its running on one rotor, started doing that when I started it the other morning. Idle is steady, but engine runs rough. This is killing me, I cannot stand my 7 being in the garage like this.

trochoid

iTrader: (6)

Sorry to tell you this, but the USA is still on the standard system, kilo what?

Percentage wise, the difference doesn't bode well. Could you convert that into psi for the older members?

Rotor13B

Try a set of new NGK's and see what happens.

BadAssRX-7

id give it a good soaking in mmo over night and a set of plugs after the mmo burn off. that might help. and yea thats a large gap so be thinking about a new motor.

Rotor13B

If I did this correctly, you have a 28-29 lbs difference in your compression. Like BadAssRX-7 said, Do a mmo treatment and hope for the best.

Rotor13B

It comes out to being 85.33psi on the front, 56.89 call it 57 on the rear. The Max difference is 21psi.

trochoid

iTrader: (6)

85 psi, if I remember correctly, is the minimum. Try the MMO and hope for stuck seals.

I take it this is the max psi for each housing, since you didn't give 6 #'s, so those #'s don't look very good.

ArmySoldier

MMO? Ill try it, I have replaced everything else, distributor, rotor, NGKs, coils, doing wires tomorrow when they arrive, and new vacuum lines as well. Just not sure what MMO is.

IanS

iTrader: (4)

Marvel mystery oil. Comes in red bottle available at auto zone, oreillys, advance, etc. Make sure and read the back of the bottle for every day use. What they are explaining now is not every day use for mmo. mmo seems to break up carbon somewhat and also cleans up oil sludge that sometimes builds up, etc. Hope it works. If not, PM me

ArmySoldier

After I hit the 'post' button, it occured to me, Marvel.... I knew that. Geez the stuff I used to know.... left most of it in Iraq and do not care to go back and get it. So, I am told I should add it right to my oil, is that right?

diabolical1

iTrader: (3)

put it directly into the combustion chambers and rotate the engine by hand, then let it soak for a day or two. you can also add it to your fuel ....

dj55b

iTrader: (2)

by the combustion chambers ... do you mean through the spark plug holes? or should it be fed through the carb?

diabolical1

iTrader: (3)

it's easiest through the carburetor, but on the SE, it's probably easier through the plug holes.