Originally Posted by Pleco

Hello Guys. Thanks for all the input. The fact that Mutha also had the same problem only after a service, put me onto the items I replaced. As I was loosing both cylinders, I took a look at the plugs (8EA as supplied by the bike shop according to their book). I could see from the colouring, that they were running very hot. When all else fails RTFM. (read the f... manual!) The manual specs a 9ea. So I go looking at the web and found the following:
Heat range

The operating temperature of a spark plug is the actual physical temperature at the tip of the spark plug within the running engine. This is determined by a number of factors, but primarily the actual temperature within the combustion chamber. There is no direct relationship between the actual operating temperature of the spark plug and spark voltage. However the level of torque currently being produced by the engine will strongly influence spark plug operating temperature because the maximum temperature and pressure occurs when the engine is operating near peak torque output (torque and RPM directly determine the power output). The temperature of the insulator responds to the thermal conditions it is exposed to in the combustion chamber but not vice versa. If the tip of the spark plug is too hot it can cause pre-ignition leading to detonation/knocking and damage may occur. If it is too cold, electrically conductive deposits may form on the insulator causing a loss of spark energy or the actual shorting-out of the spark current.

As I was experiencing similar problems, I went out this morning, and bought 9ea plugs.

Problem solved right away. Bike peaks out at 165 KMH again, and I have the surge of power back around the 7000 RPM range.

Kumuya if you are running the 8ea plugs, you must have set the timeing and or fuel mixture to compensate, or it is very cold there by you guys. We are running at about 30 deg celsius day temps here. Apparently all of the above affects the heat range of a plug.

The max torque is at abot 7200 RPM, so I change gears there about if I look for a bit of oomph! No use in running to the red line as the curve comes down quite a bit after 9000 RPM.

I hope this solution will help somebody in the future, as the bike shop books specified the wrong plug for my bike in our hotter climate.

Regards

Originally Posted by Youngatheart

I have a KLE500 with a question pertaining to spark plugs.

When I did a service at 30000km, I decided to replace the plugs, as I had taken ownership of the bike at 27000km at the beginning of March 2010 and didn't know when last the plugs had been changed. Kinda fanatical about things like this.

The owner's manual says DR9EA is the plug to be used, but after driving to, or phoning 10 bike shops, I was eventually told by one techie that I could use the DR8EA, of which they had in stock, and that it would be fine.

Firstly. I'm wanting to know if the DR8EA can make such a difference as mentioned in this thread. Should I try source DR9EAs or just clean and put the old plugs back, or can I leave the DR8EAs in?

Secondly, prior to me servicing the bike, when cruising at 80/100/120, if I opened the throttle quickly to overtake, the bike would hesitate, almost as if it was momentarily flooding or being starved. When I took off the airbox to clean the air filter when doing the service it was full of petrol.

Then, a few weeks ago, after a ride, I noticed a puddle under the bike, and on inspection discovered it was petrol running out of the drainage pipe from the air box. I checked the float levels and they measured 12mm instead of 17mm. I adjusted the levels, and the petrol running out of the air box has stopped, but the hesitation when cruising and suddenly opening the throttle is still there.

I was told that it is most probably the needles and seats that are worn, so I've ordered replacements. But I've also been told that this should not be the case at 30000km.

Could the problem be caused by the incorrect plugs now, but prior to me changing the plugs, by the incorrect float levels.