Compression Relief Valve

   / Compression Relief Valve #1  

3RRL

Super Member
Joined
Oct 20, 2005
Messages
6,931
Location
Foothills of the Giant Sequoia's, California
Tractor
55HP 4WD KAMA 554 and 4 x 4 Jinma 284
I was wondering how you guys most commonly use the compression relief valve? I have not had to use mine yet and and not even sure where it is located on my KM554. Maybe I can learn something?

Is it used primarily when working on the motor to rotate easily?
Is there a situation when you would use it while operating?
Thanks,
 
   / Compression Relief Valve #2  
????Huh???? BobG in VA
 
   / Compression Relief Valve #3  
Rob, the compression release is the knob next to the kill knob on the lower part of the dash (almost at the transmission). it is HARD to pull it on the KMs, sometimes the lever will hit the seam on the fuel tank and prevent operation. The KMs are so easy starting, it is rarly necessary to use the compression release (yes Greg it is a good idea!). Some of the tractors we have recieved, the CR was not even attached to a cable. Most modern tractors don't have them (compression release) anymore some engines still have them but not hooked up to anything (lenars and some of my Kioties and Kamas are this way).

You don't use it when running, only to make it easier for the starter to turn the engine. It will not start till you release the release (this is getting confusing /forums/images/graemlins/confused.gif).
 
   / Compression Relief Valve
  • Thread Starter
#4  
Thanks Chip,
That clears up why the knob on mine does nothing. When I asked the dealer's delivery guy who was supposed to "educate" me on using the tractor, he did not know what that knob was for. That's why I asked. I thought it was for starting only or maybe if you needed to crank the engine over without resistance for something.

My Kama starts super easy. I only use it on weekends and every-other one at that. I've never had a problem with it... starts up right away after sitting for a couple of weeks.

One thing that does happen occasionally...once in a while the solenoid will not engage the starter motor.

I have to "click" the starter on and off until it engages. Sometimes have to "tap" the starter motor to get it to engage. This occurs occasionally after shutting it down and trying to re-start. Once in a while it does it when super cold.

Any thoughts on that?

I had an old 1955 Pontiac that used to do that too.
 
   / Compression Relief Valve #5  
I too had a 1955 pontiac cheiftan... rebuilt the engine in the parking lot at college. It was a real antique, I thought at the time, nowadays a 1985 is just as old. dont get excited about 1985 anything (I do have a 1982 alfa that is fun) anyway, it might help to remove, clean and lube the linkage in the starter, the click is the solenoid trying to pull in the bendix but for some reason it cant, it does not spin the motor until the solenoid pulls all the way back and a metal disk bridges the gap between the battery cable and the lead to the motor. I had an old chevy (come to think of it I think it was the pontiac!) pulled the solenoid apart and flipped over the copper disk, worked like a champ.
 
   / Compression Relief Valve #6  
Hey Rob,
I have been told that I should use the pressure release when starting due to turning over the three large cylinders in the 454LE. Suppose to help prolong the engine, starter and solenoid life. Suppose to help making starting easier as well when solenoid is not engaging - mine does the same thing on occassion. Was really bad, due to the battery not getting a good charge because of a bad crimp.

The first couple of times I tried to use the pressure release, could not hardly budge. Did not think any human could budge that lever. Even offered to pay the air fair for any Jinma engineer that could come over here and turn the lever seated /forums/images/graemlins/grin.gif Glad no one took me up on that! As time has went along it has gotten easier to turn. Can now do seated without any issue.

Take care,
Eddie
 
   / Compression Relief Valve #7  
I agree with Eddie. I personally never start a cold engine on my KM454 without using the compression release. It's a hard pull, I have to use two hands initially. Then I hold it out with my left, to free the right for the keyswitch. I spin the engine with an eye on the oil pressure gauge. As soon as I see the oil pressure needle coming up, I let go of the compression release.

My linkage was initially striking the fuel tank seam as Chip described. Not a hard fix though. Reversing the arm to which the cable connects gave me sufficient clearance. Simple job, just hard to get at.

//greg//
 
   / Compression Relief Valve
  • Thread Starter
#8  
Chip,
</font><font color="blue" class="small">( I had an old chevy (come to think of it I think it was the pontiac!) pulled the solenoid apart and flipped over the copper disk, worked like a champ.)</font>

I have done exactly that on my old Star Chief to fix the solenoid. Beat the heck out of buying a new one.

It had that cool amber lighted indian head and chrome airplane on the hood and stars on the sides. It was 11 years old when I got it. Had some great times in that car during my High School days. Like "Happy Days" era.

Eddie,
I don't think the compression relief valve would help the solenoid to engage. If I'm not mistaken, it is activated electronically by the ignition switch. A weak battery would definitely affect it. The compression relief would help the longivity of the starter motor, though.
 
   / Compression Relief Valve #9  
I'm with Greg G on this one. With the compression removed, she spins like a top. As soon as you release the knob, she's running. I oiled the cable from both ends and worked it untill it worked smoothly.

You may want to insure the cable is adjusted correctly. This is because the lever needs full turning range to press on the valves. One way to know it adjusted correct, it won't start if you keep the knob pulled out!

patrick
 
   / Compression Relief Valve #10  
Hey Rob,
Yes, I agree it does not help the solenoid engage - sorry if I was not clear. Using the compression release just helps saving a little wear and tear on the engine components trying to turn over those large cylinders under compression.

You nailed it - the weak battery, due to the bad crimp was the source of my problem.

I do not watch the oil pressure - that's an excellent idea. I just wait until she's turning over good and release. Has started everytime without exception. Going to start watching the oil pressure and make sure it's up before I release - good suggestion Greg_g!

Thanks,
Eddie
 

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