Engine Knock from idle
05-14-2005, 01:18 PM
#2
Senior Member
SuperSport
Join Date: Mar 2005
Location: Laurel, MD
Posts: 758
Re: Engine Knock from idle
If this is truly a knock and it happens from idle, its possibly a rod knock, a sign of a bearing failure.
Have you tried higher octane gas? Does it do it all the way up? How many miles? Any history you don't know about? Any other details?
Have you tried higher octane gas? Does it do it all the way up? How many miles? Any history you don't know about? Any other details?
05-14-2005, 03:27 PM
#3
Senior Member
Superstock
Join Date: Dec 2004
Location: Independence, Oregon
Posts: 367
05-15-2005, 09:16 PM
#7
Guest
Posts: n/a
Re: Engine Knock from idle
I can only hear it when I start from a stop ... Im not sure if its just that im not giving it enough gas from the line when letting the clutch out. But it sounds like a knock. Its not happening as frequently as of late but Ive been giving it more gas from the get go.
05-16-2005, 06:37 AM
#12
Senior Member
SuperSport
Join Date: Mar 2005
Location: Laurel, MD
Posts: 758
Re: Engine Knock from idle
I can only hear it when I start from a stop ... Im not sure if its just that im not giving it enough gas from the line when letting the clutch out. But it sounds like a knock. Its not happening as frequently as of late but Ive been giving it more gas from the get go.
BTW, make sure you are starting in first. Either error will create the symptom I think you have.
The final data bit is that this may be caused by clogged idle jets. Your unknown history may have included a lot of sitting around, leading to this condition. How high do you have to rev it for a smooth takeoff on a flat surface? If it requires excessive gassing, this is likely why.
05-16-2005, 11:55 AM
#14
Senior Member
SuperSport
Join Date: Mar 2005
Location: Laurel, MD
Posts: 758
You can try soaking them in brake cleaner, techron or some other solvent overnight and blowing them out. Don't use a drill, wire, or other poker. You'll ruin them.
It's easier to just replace them.
You'll have to dissassemble the carbs and you'll need a manual. Spray the rest out, or dip them, while you are in there.
It's easier to just replace them.
You'll have to dissassemble the carbs and you'll need a manual. Spray the rest out, or dip them, while you are in there.
05-24-2005, 06:40 PM
#15
Junior Member
Squid
Join Date: May 2005
Posts: 25
Re: Engine Knock from idle
Mine does it also, I have a 01 with under 3k. At medium low idel some knocking. a clunk clunk. someone said in this topic that maybe its your chain. If its the same as mine, its not. because it also does it when the clutch isnt ingaged and bike not moving. My fix was to debaffle the pipes.
O, and why does this bike have a front wheel ? im never on it...
O, and why does this bike have a front wheel ? im never on it...
05-24-2005, 07:57 PM
#16
Moderator
MotoGP
Join Date: Dec 2004
Location: South Texas
Posts: 2,553
Re: Engine Knock from idle
Yes, a chain with stiff or frozen links will make a nice knocking sound BUT only if your moving (obviously).
A great and easy way to clean jets in carbs is with Yamaha's carb cleaner. It a well kept secret, even some shop employees don't know about as was the case at my local shop. You don't run the motor with this stuff, rather drain the carbs, unplug the fuel lines from the tank and pour it down the lines into the carbs, unplug the sprark wires and crank to help pull it in. Rock the bike a bit and let this stuff sit overnight in the carbs and then DRAIN. I repeat, don't try to run the motor with this stuff. Add fresh gas and start, voila` most cases your carbs and jets are clean.
This stuff is well known on vintage and old bike forums. I've used it and it works miracles. Worst case scenarios like sitting for years require the carbs to be pulled and soaked in it. If that doesn't work, then only the traditional teardown/rebuild will work.
A great and easy way to clean jets in carbs is with Yamaha's carb cleaner. It a well kept secret, even some shop employees don't know about as was the case at my local shop. You don't run the motor with this stuff, rather drain the carbs, unplug the fuel lines from the tank and pour it down the lines into the carbs, unplug the sprark wires and crank to help pull it in. Rock the bike a bit and let this stuff sit overnight in the carbs and then DRAIN. I repeat, don't try to run the motor with this stuff. Add fresh gas and start, voila` most cases your carbs and jets are clean.
This stuff is well known on vintage and old bike forums. I've used it and it works miracles. Worst case scenarios like sitting for years require the carbs to be pulled and soaked in it. If that doesn't work, then only the traditional teardown/rebuild will work.
05-24-2005, 08:24 PM
#17
Senior Member
SuperSport
Join Date: Mar 2005
Location: Laurel, MD
Posts: 758
Re: Engine Knock from idle
Yes, a chain with stiff or frozen links will make a nice knocking sound BUT only if your moving (obviously).
A great and easy way to clean jets in carbs is with Yamaha's carb cleaner. It a well kept secret, even some shop employees don't know about as was the case at my local shop. You don't run the motor with this stuff, rather drain the carbs, unplug the fuel lines from the tank and pour it down the lines into the carbs, unplug the sprark wires and crank to help pull it in. Rock the bike a bit and let this stuff sit overnight in the carbs and then DRAIN. I repeat, don't try to run the motor with this stuff. Add fresh gas and start, voila` most cases your carbs and jets are clean.
A great and easy way to clean jets in carbs is with Yamaha's carb cleaner. It a well kept secret, even some shop employees don't know about as was the case at my local shop. You don't run the motor with this stuff, rather drain the carbs, unplug the fuel lines from the tank and pour it down the lines into the carbs, unplug the sprark wires and crank to help pull it in. Rock the bike a bit and let this stuff sit overnight in the carbs and then DRAIN. I repeat, don't try to run the motor with this stuff. Add fresh gas and start, voila` most cases your carbs and jets are clean.
05-25-2005, 01:51 PM
#19
Senior Member
Superstock
Join Date: Jul 2004
Location: San Jose, CA
Posts: 318
How do you DRAIN??? just keep cranking? until when??
Yes, a chain with stiff or frozen links will make a nice knocking sound BUT only if your moving (obviously).
A great and easy way to clean jets in carbs is with Yamaha's carb cleaner. It a well kept secret, even some shop employees don't know about as was the case at my local shop. You don't run the motor with this stuff, rather drain the carbs, unplug the fuel lines from the tank and pour it down the lines into the carbs, unplug the sprark wires and crank to help pull it in. Rock the bike a bit and let this stuff sit overnight in the carbs and then DRAIN. I repeat, don't try to run the motor with this stuff. Add fresh gas and start, voila` most cases your carbs and jets are clean.
This stuff is well known on vintage and old bike forums. I've used it and it works miracles. Worst case scenarios like sitting for years require the carbs to be pulled and soaked in it. If that doesn't work, then only the traditional teardown/rebuild will work.
A great and easy way to clean jets in carbs is with Yamaha's carb cleaner. It a well kept secret, even some shop employees don't know about as was the case at my local shop. You don't run the motor with this stuff, rather drain the carbs, unplug the fuel lines from the tank and pour it down the lines into the carbs, unplug the sprark wires and crank to help pull it in. Rock the bike a bit and let this stuff sit overnight in the carbs and then DRAIN. I repeat, don't try to run the motor with this stuff. Add fresh gas and start, voila` most cases your carbs and jets are clean.
This stuff is well known on vintage and old bike forums. I've used it and it works miracles. Worst case scenarios like sitting for years require the carbs to be pulled and soaked in it. If that doesn't work, then only the traditional teardown/rebuild will work.
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