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Checking for Compression - '47 Chief

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  • Checking for Compression - '47 Chief

    Getting very close to the moment of truth here. Probably Friday if all goes well. Pulled each plug separately and kicked her over. The front cylinder blew my wife's thumb right off the spark plug hole. On the rear cylinder, no air pressure at the plug hole. Just a "whooosh" of air from somewhere else, possibly the exhaust? Any ideas or advice?
    Thanks!
    Mark

    1947 Indian Chief
    1984 Honda Goldwing Aspencade
    1998 Honda Valkyrie

  • #2
    Make sure the valves are closing/ lifting, check the gaps. If the valve is not closing, not much compression going on. Seen that once, a Chief would not run. Valves were way out of adjustment, adjusted them and the Chief started right up, good luck!

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    • #3
      Any tricks or tips on fixing a stuck valve other than opening everything up to get to it?
      Mark

      1947 Indian Chief
      1984 Honda Goldwing Aspencade
      1998 Honda Valkyrie

      Comment


      • #4
        Howdy Mark,

        Running some of the most excessive stem clearances it is highly unusual for an Indian V Twin to stick a valve though the exhausts on heavily worn engines can get sluggish with carbon build up. You need to look into this more closely. if your valve timing and clearances check out. A very well known supplier who shall remain nameless provided valves and guides within the last 10 years that were incompatible. The tuliping of the underside of the valve head where it flowed into the stem fouled the top of the guide just enough that the valve would not seat completely. Let's hope your motor has not suffered an old school quick fix of having the valve seats undercut to restore good sealing, which in addition to increasing guide fouling it also results in motors with torque falling off dramatically as the revs rise only moderately.

        The easiest is to pull your header to verify, a little more labor intensive for the intake. Though highly unusual as these guides are seated in iron rather than more mallible aluminum like nearly all OHV apps, if all else fails you'll need to verify your valve is centered in the seat.
        Cheerio,
        Peter
        #6510
        1950 Vincent - A Red Rapide Experience

        Comment


        • #5
          I have heard of using Marvel Mystery oil, are you sure it's stuck? Might just be out of adjustment, pretty simple to pull the heads if needed and freshen things up. I had a valve start sticking on my shovelhead years ago while riding around the country. The dealler pulled the head and wire brushed my valve stem clean and put it back together and I was back on the road - lasted several thousand miles more. Good luck, hope your in the saddle in no time.

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          • #6
            Thanks for all the help folks. Got the valve covers undone....they just slide up to show the valve stem....right? Problem is one head bolt that is located directly under the frame. I cannot figure how to get a wrench on it. It's the last one I have to get off in order to pull the head on the read cylinder. Sprayed PB Blaster all over the valve stem after I unscrewed the valve covers. And also sprayed a bunch of it in the spark plug hole. I had to drop the exhaust to get to the valve cover to the rear (exhaust valve?). I want to pull the head so I can really get a good idea of what is going on in there. But that one bolt has me stymied. Looks like I'm going to be delayed in trying to start her up.

            Any help or suggestions?

            Thanks!
            Mark

            1947 Indian Chief
            1984 Honda Goldwing Aspencade
            1998 Honda Valkyrie

            Comment


            • #7
              Mark,
              You'll need to make or purchase a low profile socket wrench. I made one by grinding the length down on a standard 5/8" socket so the depth matched the height of the head on bolt then welded it to a box end wrench. I've seen more glamorous ways to skin this cat but used what I had laying around. You'll need a new head gasket. Some like copper and some like the composite ones. I used composite mainly because I found a spare with the dowry of parts I got with the bike. Composite gaskets need re-torqued after 100 miles or so.
              Hope your compression problem turns out to be a minor issue. Good Luck
              Attached Files
              Jason Zerbini
              #21594
              Near Pittsburgh PA (Farm Country)
              Allegheny Mountain Chapter http://amcaamc.com/

              Comment


              • #8
                When I got my 39, it had been 40 years stored in a basement, stuck exhaust valve on front cyl. I removed the head and sprayed some loose juice on the stem and let it do its work. Came loose easily. I dropped the adjuster all the way down so I could get a screwdriver underneath and worked the valve up and down while spraying more penetrant to flush the orange color out. Put it back together and fixed a few other problems that sitting time brings, it runs like a bear.
                Kyle Oanes AMCA # 3046

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                • #9
                  Again...and I know it sounds redundant....but thanks to all of you. Went to Lowe's and purchased a 5/8" offset box end wrench and popped that last bolt off with ease. It's the exhaust valve that is stuck open. Intake valve and Piston work with ease. PB Blasted both valves really well and going to let it sit for a while (it's Dawgs vs. Vols today, Go Dawgs). After the game gonna Blast her again and let her sit overnight. Lots of carbon on the intake....gonna clean that off.

                  I was able to save the head gasket as well.

                  Anything else I need to take a gander at while I have that head off?

                  You guys are great!
                  Mark

                  1947 Indian Chief
                  1984 Honda Goldwing Aspencade
                  1998 Honda Valkyrie

                  Comment


                  • #10
                    Is there any oil leaking around front head gasket or head bolts,that would tell to replace front gasket and at that point replace both with new gaskets.

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                    • #11
                      Good news....exhaust valve is free. During half time I went out and turned the engine over until the intake valve was fully open. I knew then that the exhaust valve stem had some clearance from the cam lobe. I then took a hammer and lightly tapped the exhaust valve down into its seat. I did this a couple times and it freed right up. It opens and closed easily when I turn the engine over. Going to let her sit over night, turn the engine over every few hours to make sure, then button things up in the morning. I did find that the contact on the distributor rotor is broken. Will have to order one of those.

                      But at least I have all valved freed up and working.
                      Mark

                      1947 Indian Chief
                      1984 Honda Goldwing Aspencade
                      1998 Honda Valkyrie

                      Comment


                      • #12
                        Originally posted by Xtracho View Post
                        Good news....exhaust valve is free. During half time I went out and turned the engine over until the intake valve was fully open. I knew then that the exhaust valve stem had some clearance from the cam lobe. I then took a hammer and lightly tapped the exhaust valve down into its seat. I did this a couple times and it freed right up. It opens and closed easily when I turn the engine over. Going to let her sit over night, turn the engine over every few hours to make sure, then button things up in the morning. I did find that the contact on the distributor rotor is broken. Will have to order one of those.

                        But at least I have all valved freed up and working.
                        I've free'd stuck valves by clamping a vice grip to it's head and rotating it back and forth, ... (when I had less patience) .. dull vice grip, valve suffered no "knurling" effects. Penetrants used liberally.
                        good luck, glad you got this far.

                        Comment


                        • #13
                          Might want to check that none of the head bolts are bottoming, also clean threads. Should be able to pull them up snug with no gasket. Then you know you have some crush area for the gasket. If any of the bolts are bottoming, you can pull the threads before you get to your torque level. It is very frustrating to do that, when your ready for a ride - I know and have done it. Good luck.

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