Announcement

Collapse
No announcement yet.

Compression testing, last question, I promise

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Compression testing, last question, I promise

    Ok, so the 750 engine is on the frame, now I need to know, can I run a compression test before I attach the exhaust and carbuerators. I know I'm supposed to warm the engine to operating temp,then hold the throttle wide open while testing, but can I get away with this?

    #2
    That doesnt sound like a compression test to me?????

    Comment


      #3
      The way I understand a compression test, you warm the bike up, turn the bike off, remove all 4 spark plugs, thread the tester into 1 cylinder, hit the starter, hold the throttle open and read the PSI output. Repeat for other cylinders.

      Comment


        #4
        Originally posted by slopoke
        That doesnt sound like a compression test to me?????
        Why not????

        Comment


          #5
          I see. i thought your post said you were going to do it while the motoe was running wide open. sorry. I think it would work on a cold engine as well. Im not really sure. I have always run compression tests on a cold engine. But now that you say it ill bet you are correct.

          Comment


            #6
            You could do a compression test cold, but the results may not be valid.

            Better to do a leakdown test. Again, this should be done hot, but even cold will tell you if you have any major valve seat issues.

            Really though you should get the engine running first. Then do a compression test as you described.

            Comment


              #7
              What are you looking for with the compression test?

              Worn rings? Dodgy valves? Hardened valve guide seals? Too much pepperoni?

              A cold test will show up your rings, if you do a dry then a wet test. The numbers will probably look better cold than hot.

              A leakdown test will show leaking valves as well as rings. It takes longer but at least you already have pipes and carbs off so its easier. A solvent test before you put the head on will also show up leaks.

              Valve guide seals is a matter of oil consumption, which might be pointing you towards checking for bad rings. The seals like to camophlage themselves.

              Then again, compression testing will not show up the level of pepperoni. Call Dominoes. :-) And get in a six pack or two. The bike always runs better that way.

              Kim

              Comment


                #8
                Kim
                Could you possibily describe how to do a too much peperoni test. 8O 8O 8O Sound like it would be a major addition to my notes on GS cycle maintenance

                Comment


                  #9
                  Originally posted by slopoke
                  Kim
                  Could you possibily describe how to do a too much peperoni test. 8O 8O 8O Sound like it would be a major addition to my notes on GS cycle maintenance
                  A "too much pepperoni" test is carried out in the following manner.

                  Get a whole bunch of bikers together, start about 7pm late summer. After a Saturday ride is the best time. This test works best when the bike is warmed up.
                  Order in a whole stack of pizza.
                  Send someone out for a few slabs of beer.
                  Eat the pizza and drink the beer.
                  If the pizza lasts longer than the beer it means it has too much pepperoni.

                  :-)

                  Kim

                  Comment


                    #10
                    Originally posted by kkmiller
                    Originally posted by slopoke
                    Kim
                    Could you possibily describe how to do a too much peperoni test. 8O 8O 8O Sound like it would be a major addition to my notes on GS cycle maintenance
                    A "too much pepperoni" test is carried out in the following manner.

                    Get a whole bunch of bikers together, start about 7pm late summer. After a Saturday ride is the best time. This test works best when the bike is warmed up.
                    Order in a whole stack of pizza.
                    Send someone out for a few slabs of beer.
                    Eat the pizza and drink the beer.
                    If the pizza lasts longer than the beer it means it has too much pepperoni.

                    :-)

                    Kim
                    Thanks for the help, I always thought a "too much pepperoni test was if ur "exhaust" smells like burned meat, and is way too hot, 8O or if sitting on the throne burns too much . 8O I got the bike running, so I'll do a proper compression test in a bit... weekend is almost here and I need to leave for my parents place to work for the weekend.... I'm probably the only guy I know working two jobs, 200 miles apart.

                    Comment

                    Working...
                    X