I've been a member for a while but due to circumstances in life I've been unable to ride. I decided I would buy an 89 GS500 to go with my 95 that has been relegated to "parts bike" status (long story there). It has an issue that shouldn't be mine... I should have known better than to trust this slimebag kid... but anyway here I am.
The 89 had 29,XXX kms on it when I bought it. The previous owner stated he had "over 2300" in it. Engine was rebuilt, looked over by a dealer and everything is tip-top, etc etc etc. He said that he didn't ride it since August of last year (bought a CBR600) so the oil would have to be changed ASAP. Ok no problem. Bike started ok and ran ok but when I got it home is when the problems began.
Once I got it home after the 80km ride, I didn't ride it until I changed the oil. On the oil change it was black crap and the filter was dirty. Ok whatever. Thats when I notice they used some blue gasket goo (not much, I guess just to tack the oil gasket) on the oil filter cap. Ok whatever I clean it off. Change the oil and we're ready to go right?
Wrong. I drive it around on a hot day and there is this weird knock/tap/ping thats cyclical but irregular... kind of like "knock knock.............. knock knock.......... knock knock......." and the hotter the motor gets the more prounounced it is. Cold starts or if you drive it around not pushing it the sound isn't there. So I decide to do a valve job and before I do that I do a compression test.
110 left, 120 right. So much for a "fully rebuilt engine"... f'ing scumbag....
I drive the bike to work a few days ago and starting it up at work I notice a lot of smoke coming out of the exhaust. Ok no big deal its an air cooled engine tolerances are going to be loose until it warms up. I get home and just in case pull an oil check because I noticed a spot on the pavement under the bike the diameter of a tennis ball or a little smaller two days in a row. Thats when I notice that there is "gasket goo" bulging out of the cover on the left side and there is grime all over it. I wrench on the nuts and it tightens up and the oil check says I'm at the LOW point of the dipstick! After ONE WEEK!.
Anyway, I top up the oil and I do a valve adjustment and find 3 of the 4 valves REALLY tight. The exhaust valve on the right cylinder is so tight I go down two shim sizes just to get .05mm of tolerance. Ride to work last night and back and it appears that the oil leak is gone (no noticable loss of oil and no spot on the pavement) but I decide to do a compression test again anyway.
Left and right are now both 120 (I thought they were 70 but being a dork this morning I didn't have the throttle WOT when I did the test... forgive me I'm on nights this week). The spark plugs are tan but the base of the spark plugs where the threading starts are black. Thats oil blowby isn't it?
Aside from a little commiseration from people have been screwed on vehicle buys before, based on this information would anyone hazard a guess on what the most likely cause of the knock is? I have a second motor that compression-wise is borderline service (115 both cylinders) but doesn't knock like this. I'm going to swap it in just to make it through the riding season.
Id just like an idea of what I should look for when I tear down this "completely rebuilt" piece of ****.
Thanks
Hi bub,
Sorry to hear of your hassles with your purchase.
This is why I never trust anyone who tells me something has been rebuilt unless:
They can show me RECEIPTS for the work that was done.
There is actual evidence that the work was done CORRECTLY, which means I'd better NOT see any gasket sealer oozing out between engine parts.
I can see that FACTORY parts were used, based on the receipts, and not cheap, imitation junk parts.
There are always these kinds of risks when buying used vehicles, so you have to be sure that you believe what you are seeing.
You also must really check it out before you buy. Looking at the dipstick and seeing the filthy oil as you looked might have made you walk away when you saw the condition of such a simple yet critical maintenance item as regularly-scheduled oil and filter changes.
Look, now you bought it so you have to take a good look and see what to do next.
That's up to you and your budget.
What shape is the rest of the bike in?
How much did you pay for it?
When you did the compression test, were you sure that you had the throttle open all the day as you cranked the engine? That's the only way to get an accurate reading.
There are many things to look for with the noises you are hearing.
Cam end play.
Piston to cylinder wall clearance.
It could be a bad crank bearing or rod bearing.
Check what you can before tearing it apart, I agree with you. I'd recheck the compression, look inside the spark plug holes with a flashlight and see if you can see any damage, carefully check the oil for metal pieces or filings, and anything else you can see.
Good luck, man.
This is why I walk away from far more used vehicles than I ever consider buying.
Let the buyer beware is my mantra when shopping for used vehicles.
If it's not worth investing more money into it, you can always part it out to recoup some of what you lost.
Best wishes,
Trwhouse
I agree it was a bonehead move. I should have asked for receipts and I should have been more observant and done things differently. Trust me I have flamed myself enough in the past week over this stupid move. I had been living outside of Canada for quite a long time and apparently people aren't as trustworthy as I thought anymore but I digress.
The rest of the bike is in great shape. The forks aren't messed with, the frame has very little rust, the gas tank is solid. I could use my US spec bike for parts (that bike's gas tank is shot as well as a few other things) and with respect to cosmetics, take the best from each bike and put it on this one.
I don't mind doing a rebuild depending on whats wrong, but now that I think about it I don't remember if my compression test this morning was with the throttle open... DOH! I'll also grab a flashlight and see what I can discern. Its the timing of the noise (coupled with the bike having to be warm to have it occur) is what's throwing me off.
My "better" engine has a slight slip in 5th on occasion, but I'm wondering if thats just a clutch adjustment issue instead of a failing clutch. That bike has fewer Kms on it than this one.
Just rewarmed the engine and did a compression test correctly. Its 120 both cylinders now so I guess the valve adjustment helped on the left cylinder a little. They're in spec which makes me feel a little better. I'll start dismantling my 95 just in case so that if something happens the other motor will be ready to pop in and go.
EDIT - and his excuse for the oil was "I was going to change it but when I got my CBR I never got around to it because I never ride this bike" or similar wording to express the same sentiment.
Would you be willing to sell the ECU/Igniter off the parts bike? If I diagnose that as the problem on my bike I'll need one ASAP. :D
Quote from: SlimKlim on August 14, 2010, 07:29:49 AM
Would you be willing to sell the ECU/Igniter off the parts bike? If I diagnose that as the problem on my bike I'll need one ASAP. :D
Let me send you a PM on that. Are you in Canada? I only go to the states 2, maybe 3 times a year now.
That's two scams old buddy, one more and you're out.
If you're valves are too tight, they are going to compromise compression. As for the slap, the first thing I'd check is your drive chain adjustment, and the second thing I'd check is your cam chain adjuster. Piston knock and other more serious problems tend to be more regular.
Quote from: ojstinson on August 14, 2010, 08:36:36 AM
That's two scams old buddy, one more and you're out.
???
Quote from: burning1 on August 14, 2010, 08:42:26 AM
If you're valves are too tight, they are going to compromise compression. As for the slap, the first thing I'd check is your drive chain adjustment, and the second thing I'd check is your cam chain adjuster. Piston knock and other more serious problems tend to be more regular.
Drive chain was adjusted, but the problem occurs at idle. You cant really hear it when you're riding.
I'll check the cam chain adjuster on Tuesday or Wednesday. I have to get some sleep as I'm on night shift hell for a few more days.
thanks for the replies everyone
Hang in there, CanukGS500.
You'll get through this. :)
And now you'll be that much smarter the next time you look at a used bike.
Not to worry.
It's how we learn. :)
Best wishes,
Trwhouse
dont feel alone i got boned too when i bought my gs. paid way too much for a bike that wasnt quite what owner said it was. but being 35 and raining and new to bikes when i picked it up i took his word and didnt bother to ride it or run it very long. we live and learn
You could put in thicker oil (10w-50 or 20w-50) and see if that makes the slaps quieter or less severe or less frequent. if that helps ill bet on either piston slap or worn bearings. Because it gets worse when the engine is hot it sounds like the oil is getting too thin to cushion the worn parts.