82 gs450gaz low compression

[gswisconsin]

I have 140 on one cyl. and 30 on the other. I adjusted valves and now have 180 and 25. Exhaust valve on low cyl was tight. All valves now have at least .08mm clearance. Milaeage is 44k and motor smokes from valve seals like it has for the past 3 years. The question is that the bike runs fine just like it always has. It does not leak oil or blow smoke out the pipes except on startup. Plugs are ok on both cyl. They both look the same - no wetness or soot or oily residue. Is it possible to have a motor with this low compression and have no symptoms? If I would not have done a compression test I would not have believed anything was wrong because it runs fine. Or is it that I have just gotten used to the bike not running fine over a period of time and I dont know what normal is anymore for my poor old 450? I have had engine head gaskets and rings and crank pins go to pot on other makes in my 8 other bikes I have owned but I always had a symptom to show for it - poor idle, white smoke, etc. My last thought is perhaps the exhaust valve that was tight has carbon on it and is still not seating properly after only 80 miles since adjusting it or perhaps it is warped and will never seat. I'm driving it 40 miles to work everday and it accelerates and idles fine. Is this possible or am I dreaming? I have owned this bike since 2k and have not done a thing to it - not even fork seals. This is the best bike I have ever owned. The next rear tire will be its 10th. I dont know if it matters but this is an automatic transmission model. I could never find a repair manual for it and still can't. Thanks in advance for the reply. Mike

 

[BassCliff]

Greetings and Salutations!!

Greetings and Salutations!!

Hi Mr. gswisconsin,

Alas, I have no GS450GA service manual. There is an owner's manual and a wiring diagram on my website along with some other GS twin manuals that may help.

Those compression numbers are not good at all. Did you also test with a little oil in the cylinder?

Anyway, I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", the Carb Rebuild Series, and the Stator Papers. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

 

[gswisconsin]

I used oil on the original test and got 5 psi more on bad cyl. The first test was with a warm motor. This last test was done cold but I was expecting at least a little improvement over 30psi. I had the throttle wide open as on the this last test.
Thank you for the welcome BassCliff. I have been to your site and have downloaded the owners manual and wiring diagram ok but am not able to get the repair manual. It downloads for 5 or 10 minutes and then gives me an error message saying it cannot continue. Another question that has popped into my head is how long can a gs450 motor or any gs motor be expected to last with proper maintenance before it needs a major something or other? Is my 450 already in its twilight years or days? My wife tells me I dont know when to let go. So is it time to let go at 50k, 75k, ? I am seeing a lot of late model low mileage bikes of all makes and models both private and dealer stock right now. Is it time to move up 25 model years or so?

 

[BassCliff]

Hi,

To download the larger PDF files it's usually best to right-click and "Save as...". Then save them to your hard drive (i.e. "My Documents" folder).

The guys on the gstwins.com forum say they get about 75K-80K miles from their GS500 bikes until it's time for a top end refresh. There are 850 owners here with more than 100,000 miles on their bikes.

Unless you really enjoy it, sometimes it's not worth spending so much time in the garage rather than riding. You may be able to part out your 450 instead of doing the top end refresh. That would offset the cost of a newer bike for you. I'm must thinking out loud here.


Thank you for your indulgence,

BassCliff