• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

Compression test on removed engine

  • Thread starter Thread starter Karstan
  • Start date Start date
K

Karstan

Guest
Is there a way to run the compression test on an engine that has been removed from the frame? I've tried hooking up the battery and just bumping the starter to do the test that way, but I'm getting readings of zero psi. The engine ran before removal. Also, I've got all the covers off. Will just putting them back on give me what I need? Or does it need fuel?
 
With the engine removed, you would be better off doing a "leak-down" check. It doesn't require cranking of the engine and it gives you a better indication of the "health" of each cylinder.
 
Karstan said:
Is there a way to run the compression test on an engine that has been removed from the frame? I've tried hooking up the battery and just bumping the starter to do the test that way, but I'm getting readings of zero psi. The engine ran before removal. Also, I've got all the covers off. Will just putting them back on give me what I need? Or does it need fuel?
Click to expand...
You need oil in the engine and does it have carbs installed?
You should be getting something though so is the compression tool any good?
 
Old Skool: Thanks! I'll search the forums for this leak down test.

Chef & Tom: No carbs currently installed. I got a little something on cylinder #1 (about 65 psi) on the first test but I'm not getting anything now. There's a loud pumping sort of sound when I bump the starter, so it certainly sounds like there should be pressure.
 
Having the carbs removed makes no difference, it's just like having the throttles open which you would do on a compression check anyway.
Don't just bump the starter, let it crank several revolutions, then read the compression gauge.
Check the easy things first, are the valves adjusted correctly?
If the valves are too tight, there can be no compression.
Likewise if they had been burnt from running too tight, no compression.
Has the engine sat unused forever? If so, sometimes piston rings need to be freed up, although you would expect at least some compression in this case.
Can you give us a little history on this motor?
 
tkent: I bought the bike a year and half or so ago. I rode it up through last October, so it was running until then. It's been sitting for the past few months.
 
Motor running = compression
something is flawed in your compression check. Does it blow your finger off the spark plug hole when turning over the motor?
 
You must log in or register to reply here.
Back
Top