• 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.

New to an '82 GS450 L

free99

free99

Forum Mentor
Hello everyone, glad to have found a site for fellow GS motorcyclists.

I recently bought my first moto, an '82 GS450L for $300 which wasn't running well. I've done some work, but am a bit nervous to rip into the engine to check valve clearance, and I haven't done a compression test.

I want to improve my understanding, as well as have a better performing machine, but... I'm kinda broke right now.

So, the questions:
  1. Where can I get a cheap (but reasonably accurate) compression tester?
  2. Is there anything I should watch out for when I try to check the valves, as I've never played with a valve-train?
  3. The cap for the stock airbox is missing, how important is it?
  4. Would any of the above be a reason for the engine struggling to get past 5k RPM while on the center-stand?

Idle seems OK, though there's a dead spot going from 1500 -> 2500 RPM before the engine suddenly perks up.
I've cleaned the carbs using an idle ultrasonic cleaner at work and replaced the O-rings from cycleorings.com.
The petcock looks OK (no leaks overnight), and so does the intake boot, with new O-rings for the boot too. I checked for air leaks using a dash of starter fluid here and there while idling, very minimal change.

Any help or suggestions for going forward are much appreciated. Thank you! :teapot:
 
Last edited:
Hey and congrats on the new bike. For the valve clearances, I say just jump into it. You're probably going to have it apart for several days the first time you do it but if you have as much as you can on hand, the downtime should be minimal.

1. You should be able to buy or rent one for free from your local Advanced Auto Parts or Autozone. My buddy bought this one. It's the one I use and seems to work just fine. https://www.amazon.com/BlueDriver-C...coding=UTF8&psc=1&refRID=P7Y7D1JNH76YWD8MEWZ5

2. Definitely buy a new OEM valve cover gasket and replace it (partsoutlaw.com or somewhere similar). If the previous owners had neglected to do this for a while, there's a good chance you'll be scraping some old gasket off which requires a little patience. You'll also need either the suzuki valve compression tool or if you search "zip tie valve adjustment", you'll find some posts that use zip ties in the cylinder to hold the valves open. You also might find that the valve shim markings are either hard to read or gone completely so I'll typically have calipers on hand to measure the thickness of the shims.

3. The missing airbox cap is almost definitely going to cause a lean mixture. I have an extra I can mail you if you send me a private message. In fact, I have tons of extra GS450 parts I need to get rid of so let me know what else you need :)

4. The airbox cap could definitely cause that. I'd set the valve clearances first to make sure everything's all set there before troubleshooting the idle.

Somebody else is going to bring it up so I'll just do it - When you cleaned the carbs, did you completely disassemble, remove all jets, etc. before putting them in the ultrasonic and did you spray all the internal passages out with carb cleaner followed by compressed air afterwards? If not, you might have to do it again. There's a GS450 carb cleaning tutorial as well as tons of other useful info about your bike here:

http://gsarchive.bwringer.com/
 
I'll agree with sam000lee, valve clearances are pretty easy to do and the zip tie method is simple. Also agree on borrowing or renting a compression gauge if you plan on being a shade tree mechanic. It's not something you need very often unless you plan on doing a lot more work on other engines in the future.
 
Hey LAB3 & sam000lee, sorry for replying so much later than the original post. I really appreciate your help. I bought an air cover and the bike responds a lot better, no more plateau at the low end.

I dove in and removed the cover. The old gasket shattered almost like glass after gently lifting the over. (Thanks sam000lee for the prescience to get me to order a replacement gasket).

So, some questions:
My feeler gauge only goes down to 0.004mm. When I set each cam lobe to be perpendicular to the cylinder head, I could just barely fit the gauge into the gap between each spacer and cam lobe, and for two of the cylinders I could not fit the gauge in at all. Does this mean any are out of spec, ready for replacement?

Secondly, how should I remove stuck-on old gasket stuff without damaging the aluminum mating surfaces? I'd like to avoid getting grit into the engine too.

Thank you :)
 
Ah, I see that the clearance between the shim and the cam lobe actually decreases, not increases over time. I'll look into the Shim club(TM) as well.

The clymer manual mentions that there is a notch to help with popping the shims out in the shim bucket, but I didn't see one. How do I actually remove the shims?
 
free99 said:
My feeler gauge only goes down to 0.004mm.
Click to expand...
Where did you find one that goes THAT thin??? :-k
Most feeler sets are good to go down to .04mm, sometimes you can find one that goes to .03, but I have never seen one that is one tenth that thin.

I'll bet that you are either adding a zero or looking at the INCH measurements. If you are looking at INCH, you need new feelers, you need to have them in the .0015 to .003 range.

free99 said:
When I set each cam lobe to be perpendicular to the cylinder head, I could just barely fit the gauge into the gap between each spacer and cam lobe, and for two of the cylinders I could not fit the gauge in at all. Does this mean any are out of spec, ready for replacement?
Click to expand...
I have not looked in the manual for a 450. Are you sure you are supposed to have the lobe perpendicular to the head?

Before we answer questions about whether your feelers fit (or not), we will have to determine what feelers you have. The one you described above simply does not exist, so we don't know what we are dealing with.
dunno.gif


.
 
Yes, the lobe needs to be perpendicular to the head when measuring. Same thing happened to me when checking mine the first time, two of them where.too tight to get a feeler gauge into. In that case I ordered a shim that was two sizes smaller than the ones that where in there then rechecked the clearance. Note that the shims have the thickness size etched into the bottom (bucket side) of the shim.
 
LAB3 said:
Yes, the lobe needs to be perpendicular to the head when measuring. Same thing happened to me when checking mine the first time, two of them where.too tight to get a feeler gauge into. In that case I ordered a shim that was two sizes smaller than the ones that where in there then rechecked the clearance. Note that the shims have the thickness size etched into the bottom (bucket side) of the shim.
Click to expand...

Do you mean perpendicular to the valve cover part line - horizontal - or to the shim surface? 'The head' seems a bit arbitrary.
 
You must log in or register to reply here.
Back
Top