Ticking sound from the engine?

[Bonobo]

Hi all!

I recently bought a 1997 GS with about 20k miles on it as my first bike. I've ridden it for no more than a hundred miles or so, since I just got my license... uhm, today Well, I really like it and I hope to enjoy it for a lot longer.
Some miles back I changed the air and oil filters and oil (using semi-synthetic 10W40). I also got it's carbs cleaned and synced at a bike shop. I'm currently using 98 octane gas, since I didn't know better when I last filled up.

TL;DR - my concern is, that recently I have noticed a faint ticking sound from the engine, like a tiny metal hammer. It's most apparent when idling or cruising at 2-3k RPM and it has a sort of a rhythmic ascending and descending quality to it (hard to explain, maybe I'll record it later). Does this sound familiar to anyone?

Otherwise I'm satisfied with the bikes performance, I don't think it's overheating either.

Thanks for your attention!

[bill14224]

Congrats on getting your license!  

Most likely the cam chain tension or valves need adjustment, and of course make sure your oil is to the full line.  Check your oil often until you figure out how much it uses, and it will use some.  Most of us don't use synthetic for that reason.  Air-cooled bikes with some miles on them burn oil and synthetic is expensive.  Heavy duty 15W-40 truck oil is a very good alternative and it has reduced oil consumption in my case.  My bike is a 1994 with 21,000 miles on it.

Yes, 98 octane is too much for this bike.  Fill it with 87-89 next time.  If regular fuel where you live is so crappy the bike knocks, go up one grade until the knocks stop.  The idea is to run as much octane as you need and no more.

Don't worry about your bike overheating.  If the oil is full it won't overheat unless the oil pump fails, which is rare.  If the oil pump fails the engine will make a loud clattering sound as if it's empty and the red light will come on.  If that ever happens SHUT IT OFF IMMEDIATELY!

Have fun, welcome to the board, and be safe!  

[kml.krk]

[...] Yes, 98 octane is too much for this bike.  Fill it with 87-89 next time. [...]

@Bill - this guy lives in Europe - Estonia, they calculate octanes a little bit differently. European 98 is probably like 91octane US.

to the OP - the sound you hear is probably valves that need adjustment.
here is a link to a phenomenal video by Kerry Burton - he shows the entire process of shimming the valve - watch it and then you will be able to change shims on you own.
http://video.google.com/videoplay?docid=-2015554469142545363

as to the fuel - Bill is partially right - you don't need 98. 94 will do just fine.

good luck

[mister]

Not to counter the valve advice but to suggest... you should NOT be cruising along only doing 2-3k rpm. You will be putting Load on the engine. Drop down a gear and cruise at higher rpm. 4k minimum for mine for cruising along in a gear. Of course, the actual speed will vary accordingly as a result.

As for Octane...

Different countries measure it in different ways - or rather - what is called Octane is actually referring to something different. In Europe and Australia Octane rating refers to the Research Octane Number. In the US and Canada it can be the Anti Knock Index which is an average of the Research Octane Number and the Motor Octane Number. Which basically boils down to... the Octane Rating shown in the US is shown as 4 to 5 points lower than say Europe and Australia.

The higher the Octane number the less tendency for the fuel to Detonate in the cylinder prior to spark ignition. If it detonates this becomes Engine Knocking. Usually only a concern of High Compression Engines. Which in a bike is usually an engine with a compression above 9:1. Meaning, you should find No Advantage using higher octane fuel in an engine of compression 9:1 or less as knocking should Not be a problem.

However, you can test this yourself. Run a few tanks on Standard and then a few tanks on Premium and take note of the result - how does the bike Feel/Sound to you.

The Suzuki Manual says...

"Use unleaded gasolene with an octane rating of 91 or higher (Research Method). Unleaded gasoline can extend spark plug life and exhaust component life.

If Pinging or knocking is experienced, substitute higher octane grade gasoline or another brand, because there are differences between brands.

(For Canada) Your motorcycle requires unleaded gasoline with a minimum pump octane rating of 87 ((R+M) / 2 method). In some areas, the only fuels that are available are oxygenated Fuels.

Gasahol (gasoline/ethanol blends) may be used if the ethanol content is NOT greater than 10%. If gasoline and methanol, then not more than 5% methanol. If an oxygenated fuel with MTBE than not greater than 15% MTBE"

From my own personal experience, I will NOT use BP fuel. The engine runs & sounds Rougher on BP and fuel economy goes out the door - and that's on premium!

Michael

[Bonobo]

Thanks guys! I think it's pretty rare to get such high quality feedback on a message board these days! I feel warmly received

I won't be able to properly work on the bike for a week or so though. Am I risking permanent damage, if I keep riding it in the meanwhile?