Hello,
I am currently in Costa Rica on my way from Alaska to Argentina. I am riding a Yamaha XT225 and lately have noticed a funny noise every now and then. It is like a high pitched tinkling and usually occurs when I am going uphill or if I am in too high a gear for my speed. Someone has suggested this could be pinking but I don't know what that means.
Could someone possibly describe:
1. What pinking sounds like
2. What causes it
3. What damage it does
4. How to cure it

Thanks very much in advance to you technical people.
Cheers,
Lois
www.b13media.com/lois

Hi Lois
I don’t know what means “pinking” in Costa Rica but I suppose you have any wear in your machine, but without more information I can’t tell you from what. Maybe it’s the valves, the cam, cam chain or the cam chain tensioner. Sorry but I suggest is better if you make a visit to any seriously repair shop.
Try to check the valve clearance and the tensioner, put fresh oil and see.
Here we are waiting for you.
Buena suerte.
Javier

I thought it was "pinging" or Knock.
1)It sounds like you just said.

2)The bike is firing before it should.
The pressure ignites the fuel before the spark does.
A combination of low altitude and low octane gas (petrol).

3)Damage to bearings and excessive heat.
It can burn a hole in a piston.

4)Go down a gear, run at higher RPM. That will help but you should try to get a higher octane gas. At higher altitudes you can lower your octane a little at a time until it pings again then go up until it stops.
Sea level = higher octane, High altitudes = a little lower octane.

Off topic: A fake wedding ring. Thats good.
Update more often.

John

I agree with John F., pinking is usually a sign of a low octane fuel & altitude that can sometimes be lessened by retarding the ignition timing a few degrees i.e. the plug sparks when the piston is closer to TDC. This is not always easily possible on modern bikes with the ignition advance/retard controlled by an ignitor box rather than a mechanical points type set-up.

Severe pinking for long periods can & will burn a hole through the piston crown. If a higher grade fuel is unavailable, try finding some sort of octane booster to add to the fuel (off road shop?).

Steve

Hi all
Ok, sorry now I can understand what means “pinking”, here in Argentina we say “pistoneo” something like “pistoning”. Then I suppose that the other folks are rights. I don’t know if you could get better fuel or octane booster in the most place of your road. Don forgets that you are in the third world. Try to ask native people to same domestic medicine, for example in same high places they put some pieces of garlic in filter air box.
Javier

Been thinking about this & I don't think altitude would cause pinking on an otherwise healthy bike. At altitude, the air is thinner, effectively richening the air/fuel mixture. You are more likely to suffer a lack of power, feeling like the choke is still on.

It is when you're running lean i.e. too little fuel or too much air that detonation or pinking will occur. I used to race heavily tuned Lambretta's in the 80's and had a collection of holed pistons due to my jetting/timing errors.

At worst, riding at altitude will "coke" your engine up a little and your fuel economy may suffer also.

If not at altitude & still pinking, then the cause is probaby down to incorrect ignition timing, incorrect spark plug, fuel octane or impending engine trauma.

Steve

It's low altitude with a high compression engine 9.5:1 and low octane fuel that will cause pinking. If you can not get a higher octane fuel keep your RPM's up.
If you are going to accelerate or go up hill down shift.
If it starts pinking down shift.
John

Thanks everyone,

Well, I have been buying the 'best' gas since leaving the States (ie. the highest octane rating).

I have definitely had altitude trouble at anything around 10,000ft and higher. But the symptons were more a lack of power and spluttering.

Today I rode from Costa Rica into Panama. The highway through Panama is near sea level and the bike ran much better (I had filled up with 95 octane gas). But still there was the ocassional pinking/pinging noise when I went uphill.

How long will it take to make a hole in my piston? I see a sleepless night ahead...!

Thanks again.
Lois

I have no first hand experance thank goodness, but my understanding is it doesn't take long sometimes, other times it doesn't happen. If you have my luck you will be in the middle of nowhere when it happens. Try pulling your plug and see if it is fouled etc. Also make sure your plug wire is in good shape and even consider replacing the spark plug and wire. Start with the simple and cheap stuff first. Nothing like replacing several hundred dollars worth of parts to find the problem costs $5.00. Trust me I have done that. Is your timing set automatically or can you adjust it. Also look at the ingition if there is anything there to replace. Its hard to tell what is wrong without hearing and riding the bike, but try these simple tune up procedures. Also when are you due for a valve adjustment? Good luck. Oh yea, since you are getting good gas now drain your carbs to make sure you don't have any crap in them.

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John

[This message has been edited by ekaphoto (edited 27 September 2003).]