Rattling Sound on Acceleration

Leo · 07-09-2007, 03:13 AM

I find that when I accelerate my Lifan LF200GY-5, I get a rattling sound (can't think of a better way to describe it). I'm not sure whether this is coming from the engine or whether it is something else vibrating. I don't get excessive vibration from the bike as others seem to be experiencing. I have checked the engine mounting bolts and any other bolts that are in that area. This only happens when I accelerate under load. The engine sounds fine when I blip the throttle in neutral.
The bike runs great and more than anything the noise is annoying. I do have some rattling in my muffler, but I don't think that is the source of this.
Is this normal?

Danno · 07-09-2007, 05:29 AM

Hi
I know what u are talking about, does it sound like its coming from the top of the engine?. When i got my bike it had a rattle, after about 300km it became horrible, my problem was that the very bottom back engine mount bolt didn't have enough thread on it, even though the bolt was done up tight it still had about 1/2 a mm of movement, over time it had moved and started to wear and became looser. I just put one washer and one locking washer on there, tightened her back up and the bike ran smooth as, no more nasty rattle. Hope this helps.

mblas3 · 07-09-2007, 08:43 AM

Hello,

Check your skid plate. Mine was making contact in three places until I hammered them to give more clearance.

Mark

knothead · 07-09-2007, 01:40 PM

Check your toolkit. If you slide the screwdriver bits into the sparkplug socket you can wind up with a rattle even though the kit is strapped in solid.

freekshow · 07-09-2007, 02:46 PM

muffler?

Jim · 07-09-2007, 09:54 PM

Quote:

Originally Posted by freekshow

muffler?

Ditto this one, I would check on that.

TeamCheap · 07-09-2007, 10:17 PM

Hmm, would the muffler sound one way when standing still as he blips the throttle but sound different when under a load? (I suppose it could)

He said it makes the noise when under a load on acceleration.

I'd remove the engine case chain guard cover and have look to see if anything is out of whack.I'd actually look the whole chain /sprockets/rear hub/wheel over real well.
Look to see if the chain has rubbed anything (swingarm, engine case, chain guard,frame)

It's pretty easy to spot a loose chain check the adjustment if you havnt already.
We've had our chains loosen up and rub a little on the engine case and if it had gotten real bad it would have locked up and done some bad damage.
Loose/broken engine mount bolts will loosen the chain up very quickly and is in fact what I seen on my wifes bike.(glad we caught it)

lol it's probally just the muffler

Jim · 07-09-2007, 10:58 PM

Quote:

Originally Posted by TeamCheap

lol it's probally just the muffler

yeah mine was always rattling away at different times, not really when it idle'd though.

I think almost all the welds inside my muffler were broken.

AZ200cc · 07-09-2007, 11:24 PM

My headlight Bezel drove me nuts for a while...I doubt that is the problem, but it buzzed at certain RPM'S...

Leo · 07-10-2007, 02:47 AM

Hi All

Thanks for all the great tips! I added a flat and lock washer to the lower rear engine mount bolt as suggested by Danno and checked the skidplate as suggested by mblas3. I hadn't noticed before but there was a tab sticking down from the engine case (just in front of the oil drain plug) that was touching the skid plate on one corner. Rather than try to bend the plate, I drilled a hole through it where the contact was and added a few washers as spacers to the back skidplate mounting bolts. I even moved my screwdriver blades out of the sparkplug socket as suggested by knothead.

The rattling sound has gone away almost completely. I can actually hear the exhaust now.

Nothing like the sound of a big single to put a smile on your face!

Thanks again to everyone for your tips. I will have a closer look at my chain, but I think it is adjusted OK.

For Jim, are you finding the BC bugs to be brutal the last few days? I wouldn't want to yawn while riding down the road!

Cheers
Leo

Jim · 07-10-2007, 02:57 AM

Hey Leo, hadn't noticed your from langley before, yeah, the last few days I got tons of mosqito bites... they tell me saskatchewan is bad but i was there a couple weeks ago and no problems like here...

molypod · 07-10-2007, 11:42 AM

Quote:

Originally Posted by Jim

Hey Leo, hadn't noticed your from langley before, yeah, the last few days I got tons of mosqito bites... they tell me saskatchewan is bad but i was there a couple weeks ago and no problems like here...

F...... bugs.
I was in Mission the other night to see Transformers and I got bitten several times just walking to my car.
Kamloops on the weekend and not a bug in sight.
the Wack has bugs but not where I live ( Sardis)

dra423 · 03-08-2009, 01:00 PM

I searched for rattle and found this post. After reading it I went out to look at the top engine mount and BINGO nut and washer are gone. Thanks for all the posts I am a long time reader and would never have a china bike if it wasn't for this web site.

Jim · 03-08-2009, 05:41 PM

Glad you found what you were looking for.

TheRealWorld · 03-09-2009, 11:33 PM

The noise you describe sounds like you may have a bit of detonation or pinging. It sound like you have solved the problem, but if you get a little of it in the future, try a little higher octane gas and see it that makes a difference.

07-09-2007, 03:13 AM	#1
Leo Join Date: Mar 2007 Location: Langley BC, Canada Posts: 34	Rattling Sound on Acceleration I find that when I accelerate my Lifan LF200GY-5, I get a rattling sound (can't think of a better way to describe it). I'm not sure whether this is coming from the engine or whether it is something else vibrating. I don't get excessive vibration from the bike as others seem to be experiencing. I have checked the engine mounting bolts and any other bolts that are in that area. This only happens when I accelerate under load. The engine sounds fine when I blip the throttle in neutral. The bike runs great and more than anything the noise is annoying. I do have some rattling in my muffler, but I don't think that is the source of this. Is this normal?
	0

07-09-2007, 11:24 PM	#9
AZ200cc Join Date: Apr 2007 Location: Show Low Arizona Posts: 2,889	My headlight Bezel drove me nuts for a while...I doubt that is the problem, but it buzzed at certain RPM'S... __________________ <br />2001 Suzuki DR200SE<br />1997 Suzuki RM250 YIKES<br />1995 Yamaha Breeze 125 daughters<br />1991 Honda XR80r Restored<br />maybe a 2003 Yamaha TTR90
	0

07-10-2007, 02:47 AM	#10
Leo Join Date: Mar 2007 Location: Langley BC, Canada Posts: 34	Update Hi All Thanks for all the great tips! I added a flat and lock washer to the lower rear engine mount bolt as suggested by Danno and checked the skidplate as suggested by mblas3. I hadn't noticed before but there was a tab sticking down from the engine case (just in front of the oil drain plug) that was touching the skid plate on one corner. Rather than try to bend the plate, I drilled a hole through it where the contact was and added a few washers as spacers to the back skidplate mounting bolts. I even moved my screwdriver blades out of the sparkplug socket as suggested by knothead. The rattling sound has gone away almost completely. I can actually hear the exhaust now. Nothing like the sound of a big single to put a smile on your face! Thanks again to everyone for your tips. I will have a closer look at my chain, but I think it is adjusted OK. For Jim, are you finding the BC bugs to be brutal the last few days? I wouldn't want to yawn while riding down the road! Cheers Leo
	0

03-08-2009, 01:00 PM	#13
dra423 Join Date: Jul 2008 Location: Tampa, FL Posts: 10	Thank you! I searched for rattle and found this post. After reading it I went out to look at the top engine mount and BINGO nut and washer are gone. Thanks for all the posts I am a long time reader and would never have a china bike if it wasn't for this web site.
	0

03-08-2009, 05:41 PM	#14
Jim Join Date: Mar 2007 Location: Abbotsford, BC, Canada Posts: 4,880	Glad you found what you were looking for. __________________ "Be excellent to each other" "We are all human. Let's start to prove it!"
	0

07-09-2007, 05:29 AM	#2
Danno Join Date: Jun 2007 Location: Aus Posts: 29	Hi I know what u are talking about, does it sound like its coming from the top of the engine?. When i got my bike it had a rattle, after about 300km it became horrible, my problem was that the very bottom back engine mount bolt didn't have enough thread on it, even though the bolt was done up tight it still had about 1/2 a mm of movement, over time it had moved and started to wear and became looser. I just put one washer and one locking washer on there, tightened her back up and the bike ran smooth as, no more nasty rattle. Hope this helps.
	0

07-09-2007, 08:43 AM	#3
mblas3 Join Date: Mar 2007 Posts: 120	Hello, Check your skid plate. Mine was making contact in three places until I hammered them to give more clearance. Mark
	0

07-09-2007, 01:40 PM	#4
knothead Join Date: May 2007 Location: In the land of the busted up ricebowl Posts: 815	Check your toolkit. If you slide the screwdriver bits into the sparkplug socket you can wind up with a rattle even though the kit is strapped in solid.
	0

07-09-2007, 02:46 PM	#5
freekshow Join Date: Jul 2007 Location: ohio Posts: 31	muffler?
	0

07-09-2007, 10:17 PM	#7
TeamCheap Join Date: Jun 2006 Location: directly under the earths sun............NOW Posts: 2,302	Hmm, would the muffler sound one way when standing still as he blips the throttle but sound different when under a load? (I suppose it could) He said it makes the noise when under a load on acceleration. I'd remove the engine case chain guard cover and have look to see if anything is out of whack.I'd actually look the whole chain /sprockets/rear hub/wheel over real well. Look to see if the chain has rubbed anything (swingarm, engine case, chain guard,frame) It's pretty easy to spot a loose chain check the adjustment if you havnt already. We've had our chains loosen up and rub a little on the engine case and if it had gotten real bad it would have locked up and done some bad damage. Loose/broken engine mount bolts will loosen the chain up very quickly and is in fact what I seen on my wifes bike.(glad we caught it) lol it's probally just the muffler
	0

07-10-2007, 02:57 AM	#11
Jim Join Date: Mar 2007 Location: Abbotsford, BC, Canada Posts: 4,880	Hey Leo, hadn't noticed your from langley before, yeah, the last few days I got tons of mosqito bites... they tell me saskatchewan is bad but i was there a couple weeks ago and no problems like here...
	0

03-09-2009, 11:33 PM	#15
TheRealWorld Join Date: Jun 2008 Posts: 817	The noise you describe sounds like you may have a bit of detonation or pinging. It sound like you have solved the problem, but if you get a little of it in the future, try a little higher octane gas and see it that makes a difference.
	0