New motor down on comp and power

Collapse

Desktop Ad Forum Top

Collapse

Mobile ad top forum

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • TheHumbleWelder
    Senior Member
    • Apr 2017
    • 109

    New motor down on comp and power

    Looking for honest opinions here!
    engine is a 108" shovelution; STD bathtub chamber evo heads, axtell billet iron shovel cylinders, JE pistons ect.
    Just put about 600ish miles on it and now It feels as if its down on power. it sure as hell is down on compression. for the first 400ish miles it took my entire weight with TWO legs on the kicker to push it thru to start it, now its more or less the same as a stock evo as I can kick it thru relatively easily with one leg. But it also starts super easy now, 1 kick no matter the temp.

    My thoughts are my rings are either broken or Ive scored the cylinders SO bad im getting leaked compression. What leads me to that is when the bike is good and warm (over 50 miles) i take the oil fill cap and see white smoke puff out. not a lot but its noticeable. nothing from exhaust tho. Take the plugs out and theres a thin film of oil on top of them. plugs have no oil on them that I can tell.
    Bike still wheelies in 1st but feels like its got a bigger cam in it, as in the torque curve feels low till higher RPM

    I'm at a loss. debating weather to keep riding it this season or tare it down and look.

    -Edit- Forgot to mention I bought the motor "new" from nitrofrankies. after taking the heads off before I ran it I noticed there were slight vertical lines in both cylinders. couldnt feel them with my finger nail so I put it back together and didnt think twice. Maybe that fucked up my rings seating properly
    Last edited by TheHumbleWelder; 08-03-2021, 3:15 PM.
  • JBinNC
    Senior Member
    • Dec 2018
    • 2713

    #2
    The slight vertical lines will show up where the ring gaps are in fresh cylinders, after you turn the motor through a few times. No big deal.

    My take, based only on your description (of course):

    The pistons were fit too tight in the cast iron cylinders, and they have galled and scored the cylinders.

    Or, and this is easy, but a long shot, the head gaskets are blown to the oil returns (not common on evos) and it's leaking oil and compression.

    A leak check should maybe help, or at least a compression test, but the heads may well have to come off for a look see. Got a bore scope handy?

    Jim

    Comment

    • TheHumbleWelder
      Senior Member
      • Apr 2017
      • 109

      #3
      Originally posted by JBinNC
      The slight vertical lines will show up where the ring gaps are in fresh cylinders, after you turn the motor through a few times. No big deal.

      My take, based only on your description (of course):

      The pistons were fit too tight in the cast iron cylinders, and they have galled and scored the cylinders.

      Or, and this is easy, but a long shot, the head gaskets are blown to the oil returns (not common on evos) and it's leaking oil and compression.

      A leak check should maybe help, or at least a compression test, but the heads may well have to come off for a look see. Got a bore scope handy?

      Jim
      Thanks for the input jim!
      I'm thinking maybe it is galling or bad ring seating. the pistons were from axtell themselves so I'm assuming they were the proper size, but I may have been too rough during initial break in maybe?
      She got external head drains on it due to using shovel style cylinders.
      Forgot to mention that its a bottom breather too. And no smoke coming from breather tube
      Used one of my tiny mirrors and a flash light to look into the spark plug holes best i can, cylinders arent near as bad as i assumed. theyve got very slight lines vertically but no gouges or galled aluminum on em.
      ill re-do my pushrods for shits n giggles. but they wouldnt explain why im getting the puffs of white smoke from my oil bag.
      Last edited by TheHumbleWelder; 08-03-2021, 5:28 PM.

      Comment

      • Dragstews
        Senior Member
        • Sep 2010
        • 13739

        #4
        Ron uses J&E pistons ...
        If you see the need to do a clean up bore, ya might need to get with him for replacements ..
        (515-243-2518)
        Take my 45 and outrun em all ..

        Comment

        • confab
          Senior Member
          • May 2019
          • 1337

          #5
          (Noob comment warning)

          The heads don't need re-torqued, do they?

          Comment

          • Dragstews
            Senior Member
            • Sep 2010
            • 13739

            #6
            That may be hard to archive with Evo heads ...
            Two of the head bolts are under the rocker box ...
            Take my 45 and outrun em all ..

            Comment

            • TheHumbleWelder
              Senior Member
              • Apr 2017
              • 109

              #7
              Originally posted by confab
              (Noob comment warning)

              The heads don't need re-torqued, do they?
              i dont think they do, but my engine is a little unique in that it doesnt use thru bolts, the 4 head bolts bolt into the cylinders and the cylinders bolt into the case, like a shovelhead

              Comment

              • Dragstews
                Senior Member
                • Sep 2010
                • 13739

                #8
                ... /// http://www.chopcult.com/forum/showthread.php?t=52172 \\\ ...
                Take my 45 and outrun em all ..

                Comment

                • confab
                  Senior Member
                  • May 2019
                  • 1337

                  #9
                  Originally posted by Dragstews
                  Oh my.. Shovelution is crazy shit.

                  Comment

                  • TheHumbleWelder
                    Senior Member
                    • Apr 2017
                    • 109

                    #10
                    Good thread info dragstews. Mine is set up slightly different. I'm using a top fuel style std head with a cylinder fire ring and an o-ring as a head gasket.
                    Here's a picture of the chamber before I put it all together
                    Click image for larger version

Name:	IMG_20210731_182606_133.jpg
Views:	1
Size:	105.2 KB
ID:	1319375
                    Click image for larger version

Name:	IMG_20210731_182606_075.jpg
Views:	1
Size:	282.8 KB
ID:	1319376
                    Click image for larger version

Name:	IMG_20210731_182606_109.jpg
Views:	2
Size:	292.7 KB
ID:	1319374

                    Comment

                    • pan620
                      Senior Member
                      • Feb 2013
                      • 156

                      #11
                      You say in the title for the first post " New motor down on comp and power", but you do not say what the comp. test showed, have you done one or using your kicker pressure for that?

                      Comment

                      • TheHumbleWelder
                        Senior Member
                        • Apr 2017
                        • 109

                        #12
                        Originally posted by pan620
                        You say in the title for the first post " New motor down on comp and power", but you do not say what the comp. test showed, have you done one or using your kicker pressure for that?
                        Haven't done a comp test yet, got a tester on order now. I'm going simply off of kicking effort, which is significantly less than before. It doesn't have zero compression just a ton less than what it had

                        Comment

                        • JBinNC
                          Senior Member
                          • Dec 2018
                          • 2713

                          #13
                          NICE!

                          Jim

                          Comment

                          • TheHumbleWelder
                            Senior Member
                            • Apr 2017
                            • 109

                            #14
                            Originally posted by JBinNC
                            NICE!

                            Jim
                            Thanks Jim!

                            Comment

                            • JBinNC
                              Senior Member
                              • Dec 2018
                              • 2713

                              #15
                              Oil filter mount bottom bolt miss the hole? Mock-up pic?

                              Jim

                              Comment

                              300 mobile ad bottom forum

                              Collapse
                              Working...
                              ;