Hey everyone,

Might be coming back to the yellow side after a brief excursion into green...

I have the possibility to buy a 2003 GS for cheap (well, cheap for Canada, we pay a lot for used bikes here)..  It has some dings, but the main thing is that the owner says that there is low compression in the right cylinder.   It has 21,000km (~13,000 miles) on it, and this owner has put 16,000 of those km on it.  It still runs, but with very low power.

So my question is, what is the likelihood of this just being tight valves?   Then I'd get a great deal on the bike, since it sounds like the owner doesn't know much mechanically.  However, if it's a more serious problem (rings or whatever), then I don't have the expertise/time to fix it myself, so I'd be shelling out the big bucks for a rebuild or new engine.

With the low mileage and relatively new bike, I think it's unlikely that it would be something serious, but would like some feedback.  Has anyone encountered a bike like that which needed a rebuild after 13,000 miles?   I'm wondering what my chances are here..

Thanks,
Leo

Yes tight valves can cause low compression.
Unless you check and see them being tight you cant assume it is the issue though. It can be a bad ring seal, worn cylinder, or a burnt or a defective valve.
Cool.
Budha.

I'm suspicious too.  According to those who keep track here, most notably GSJack, it's very uncommon for a GS to have tight valves after so few miles.  My guess is the bike has been beaten like drums at a Metallica concert and is damaged.  Beware.

The owner knows more about bikes if s/he has specs on the compression....yes, common for the gs to have valve clearance problems. I forget, does the 2003 model have the oil cooler? I had valve issues at 13,000 miles, and I have a '96...no oil cooler. I'm from Minnesota, and so I know to look out for rusted choke cables or rust in the gas tank.

Given the low mileage, and that the compression is low on one cylinder only, its likely that the valve clearance wasn't checked enough and an exhaust valve was running tight and is damaged. HOWEVER, it could have been abused and there is some other problem. I'd check the compression myself to get a better idea what the problem is. If one is low, put a spoonful of oil in that cylinder and check it again. If it improves a lot, it's a cylinder/piston/ring issue. If not, its a valve.

Your call!

Quote from: the mole on October 03, 2009, 01:04:06 AM
I'd check the compression myself to get a better idea what the problem is. If one is low, put a spoonful of oil in that cylinder and check it again. If it improves a lot, it's a cylinder/piston/ring issue. If not, its a valve.

Your call!

+1

Do a compression test yourself as the mole says to see if it is a ring issue.  The '01 I purchased at 11k miles had a burnt exhaust valve.

-Jessie

Rule#1 Dont assume anything. There are numerous reasons for low compression and a sticky valve is a long shot.

There is a saying......"A cheap bike always turns into an expensive bike"........Tell him its worth little more than scrap in this condition, and lets be honest it is  . Then say you will do him a favour because you like the colour and offer him half of what he is asking. If he bites you have cash to put towards a secondhand head or a rebore/new pots/rings, if he doesnt...well you havent lost anything.

Quote from: Ry_Guy on October 02, 2009, 11:56:45 PM
The owner knows more about bikes if s/he has specs on the compression....yes, common for the gs to have valve clearance problems. I forget, does the 2003 model have the oil cooler? I had valve issues at 13,000 miles, and I have a '96...no oil cooler. I'm from Minnesota, and so I know to look out for rusted choke cables or rust in the gas tank.

Thanks for all your responses.

Yeah he got a home mechanic to measure the compression.   
And this is before they put the oil cooler on.  I think that was the next year.

Probably not worth it then.  It's cheaper, but not dirt cheap.  I'll keep looking.