VTRsurfer

Detonation, or pinging, can be caused by a bad load of gas. If that's the case, it would have sounded like marbles were bouncing around on top of the pistons when the engine is under load. To check for detonation roll on the throttle from a low rpm (say 2500 or slightly lower) in 3rd gear or higher. If you're going uphill it'll work better for this test.

But didn't you say you heard the noise at idle? Detonation doesn't happen at idle.

Okay, I answered that question by reading your first post. Do the roll on under load test.

I got a bad load of gas from a station that was .20 cheaper than anywhere else (gas was just over a buck a gallon then). This was in the late '80s. My truck pinged like crazy. After getting the tank about half empty, I filled up at another station. Pinging went away. Tried the cheap station 2 weeks later...pinging. I've never bought cheap gas since.

newbierider77

Man I hope this is the case..Cant do the test quite yet..Out of state plates, bad tabs, no endorsment..Well I will see what I can do? haha Thanks for the reply

OldGuy

One comment re valves. You don't mention the mileage of your bike. At our dealership we find many owners of sportbikes (GSXRs,ZXRs,CBRs,VTRs,whatever) sell their bikes around the 16000 mile (24000 km) mark to avoid having to pay to have their valve clearances inspected/adjusted (should be done every 16000 mi/24000 km on the VTR). If you bought your bike used and the mileage is greater than 16000 miles and you don't know whether the valves have been checked or not I would recommend having them done.

darkember

There are other areas that have not been mentioned that could attribute to cause this noise. These are the oil & water pump drive chains which do not have any tensioners attached to them.

My bike has a low level knocking when hot at idle which disappears when I rev passed 3K. I have standard cans on so I can defo hear it go away. I will be checking all that I have read so far in the hope to isolate it. My valves do need checking as well.

nath981

welcome darkember! valves, ccts and tps at minimum, and sync carbs.

plum555

I have the same knocking issue when hot at idle, started 2 weeks ago. Pinpointed the sound to the right crankcase cover. Removed it to find that the water pump drive chain is excesssivly slack and could easily be the source of the my knocking sound. Nobody talks about these chains in this forum(??). Does anybody have specs to these chains that we can compare to? I just don't want to buy a new one and it to be just the same as the old!!

GTS

Chains don't usually make a knocking sound. They give more of a rattle or slapping sounds. Most likely if it's coming from the right side and it's a knocking it's the primary drives gears. Sorry if this is redundant info I didn't go back and read through the entire post.