stretched cam chain

alex.s · May 20th, 2012, 01:08 AM

theres too much slack in my cam chain even when the tensioner is fully extended and its smacking around in there. anyone ever swapped the cam chain before? it seems pretty straight foreward... clutch cover and valve cover off, cct off, cams off, chain out and replace... put back together... right?

Racer x · May 20th, 2012, 04:41 AM

nope
you have to split the case and lift the crank up to get the chain out. it goes around the crank and has no link.
It is odd to stretch a cam chain. are you sure the tension er has not failed?

sombo · May 20th, 2012, 06:14 AM

Oh it stretches, all chains stretch from use. I had to replace my cam chain in my 1994 last summer. The chain was $60, and the work was over to $600 because, like you said, the case had to be split open to get the chain off.

alex.s · May 20th, 2012, 12:53 PM

hmm... the tensioner seems to work fine... but it goes all the way out and the chain still has slack... to the point that it hits the case. im worried it will jump and i'll wind up smashing valves into pistons... what do you think the chances of that are, eric?

i'm wondering if it will hold up for 3 practice sessions and a race... if it will i'll run them next week and tear it down after. if its risky then maybe i'll skip the race weekend

flynjay · May 20th, 2012, 03:22 PM

Quote:

Originally Posted by alex.s

hmm... the tensioner seems to work fine... but it goes all the way out and the chain still has slack... to the point that it hits the case. im worried it will jump and i'll wind up smashing valves into pistons... what do you think the chances of that are, eric?

i'm wondering if it will hold up for 3 practice sessions and a race... if it will i'll run them next week and tear it down after. if its risky then maybe i'll skip the race weekend

The odds are pretty good. Mine did that last month. Valves are all buggered up.

Runs fine now..... once I replaced the motor.

alex.s · May 20th, 2012, 03:32 PM

its a good thing engines are cheap and i have other bikes. anyone ever locked a motor on the track before? i've seen some videos. they make pretty cool crashes

Racer x · May 20th, 2012, 04:19 PM

My friend had a two strike lock up at over 100 mph. Quick clutch work saved it..

Yes if it's slapping that bad don't risk it. APE sells a manual tensioner for the 08 and newer.

cuong-nutz · May 20th, 2012, 06:04 PM

Oh. Caca. How many miles do you have on your bike.

Kevin2109 · May 21st, 2012, 12:03 PM

Quote:

Originally Posted by Racer x

My friend had a two strike lock up at over 100 mph. Quick clutch work saved it..

Yes if it's slapping that bad don't risk it. APE sells a manual tensioner for the 08 and newer.

buy the APE, I need to tighten my APE down again, just started ticking last night

CZroe · June 11th, 2012, 09:42 PM

My chain breaker has a cam chain pin and I saw a youtube video where someone replaced theirs on a dirt bike "the easy way" by splitting it, attaching to the new chain with a wire and turning the engine over until it came out the other side, preserving the timing. I'm still not sure how he connected the chain together without a master link of some kind.

red5 · June 12th, 2012, 07:33 AM

Quote:

Originally Posted by alex.s

i'm wondering if it will hold up for 3 practice sessions and a race... if it will i'll run them next week and tear it down after. if its risky then maybe i'll skip the race weekend

Does it not run like crap? If it is stretched enough to slap around, seems the timing would be way late.

alex.s · June 12th, 2012, 09:24 AM

bike runs fantastic

cuong-nutz · June 12th, 2012, 10:20 AM

Too lazy to re read but did the slack cause your motor to fail?

alex.s · June 12th, 2012, 10:35 AM

no. the chain isnt stretched. the noise seems to be from the chain guide itself tapping the cct. not sure why it makes noise but the chain is within spec.

greg737 · June 12th, 2012, 11:24 AM

On the old gen side there have been guys who've measured their worn cam chain at various points and they discovered that cam chains almost never stretch (wear) uniformly.

Instead the worn chain will actually be within wear tolerance measurement spec over some lengths of it and way beyond wear tolorance when measured at other points along the chain. This uneven wear sets up a "tight-loose-tight-loose" situation as the cam chain runs around across the cam gears and the engine gear. That's why it starts to make that knocking sound, and that's why it sometimes beats the cam chain tensioner to pieces.

The cam chain tensioner is designed to absorb the relatively slow changes in cam chain tension (a "lash" effect) that are caused by normal engine accelerations and decelerations. The cam chain tensioner is not capable of dealing with the extremely rapid "tight-loose-tight-loose" high-frequency lash that an unevenly worn cam chain deals out.

alex.s · June 12th, 2012, 03:29 PM

thats a good point greg. i measured it at a few points but really to be sure it should be removed. looking at the pins, they did look uniform and i couldn't see any stretching. but without measuring the entire thing it very well could be partly stretched.

alex.s · June 12th, 2012, 03:33 PM

its not an old engine and hasn't suffered any oil starvation so the only reason the cam chain would have stretched i think is if something got in there, or somehow the cam shaft locked for a second or something. i could see pregen cam chains stretching unevenly after sitting in the same spot for years with 50k miles on them already then start up and ran before changing all the fluids. but on a fairly new engine seems iffy

Racer x · June 12th, 2012, 05:30 PM

Quote:

Originally Posted by greg737

On the old gen side there have been guys who've measured their worn cam chain at various points and they discovered that cam chains almost never stretch (wear) uniformly.

Instead the worn chain will actually be within wear tolerance measurement spec over some lengths of it and way beyond wear tolorance when measured at other points along the chain. This uneven wear sets up a "tight-loose-tight-loose" situation as the cam chain runs around across the cam gears and the engine gear. That's why it starts to make that knocking sound, and that's why it sometimes beats the cam chain tensioner to pieces.

The cam chain tensioner is designed to absorb the relatively slow changes in cam chain tension (a "lash" effect) that are caused by normal engine accelerations and decelerations. The cam chain tensioner is not capable of dealing with the extremely rapid "tight-loose-tight-loose" high-frequency lash that an unevenly worn cam chain deals out.

I will check the one I have over many spots and see what I get.

Scattcatt · June 28th, 2012, 01:57 AM

Bringing this thread back to life. What exactly does this sound like? I ask because I've noticed a slapping sound in my engine for a while now too that just doesn't sound right. It kind of slaps for a few revolutions then stops for a few revolutions and the pattern repeats.

I have not inspected anything yet as I've been reading through these threads to try and get an idea of what's going on. I have an 08 with just over 16k miles. Seems pretty low to me judging from these other high mileages I've read about regarding this issue.

CZroe · June 28th, 2012, 02:49 PM

Quote:

Originally Posted by Scattcatt

Bringing this thread back to life. What exactly does this sound like? I ask because I've noticed a slapping sound in my engine for a while now too that just doesn't sound right. It kind of slaps for a few revolutions then stops for a few revolutions and the pattern repeats.

I have not inspected anything yet as I've been reading through these threads to try and get an idea of what's going on. I have an 08 with just over 16k miles. Seems pretty low to me judging from these other high mileages I've read about regarding this issue.

Have you replaced the drive chain yet? Probably about time.

Scattcatt · June 28th, 2012, 04:40 PM

The drive chain as in the chain that goes to the rear wheel? Yes, this is the bike's 3rd one at minimum (bought it used with an aftermarket chain already on it, then I later replaced that one)

CZroe · June 28th, 2012, 05:10 PM

Will this work well on our bike?

Link to original page on YouTube.

Quote:

Originally Posted by Scattcatt

The drive chain as in the chain that goes to the rear wheel? Yes, this is the bike's 3rd one at minimum (bought it used with an aftermarket chain already on it, then I later replaced that one)

Yep. Just wanted to rule that out.

alex.s · June 28th, 2012, 06:52 PM

i'm just gonna go ahead and say no, it's a bad idea to cut and reweld your cam chain. will it work? if you do it perfectly. can you **** everything up in the blink of an eye? yep.

now, if you had a proper cam chain press like i do... thats another story

May 20th, 2012, 01:08 AM	#1
alex.s wat Name: wat Location: tustin/long beach Join Date: Sep 2009 Motorcycle(s): wat Posts: Too much. Blog Entries: 5 MOTM - Oct '12, Feb '14	stretched cam chain theres too much slack in my cam chain even when the tensioner is fully extended and its smacking around in there. anyone ever swapped the cam chain before? it seems pretty straight foreward... clutch cover and valve cover off, cct off, cams off, chain out and replace... put back together... right? __________________________________________________

May 20th, 2012, 06:14 AM	#3
sombo Newb..... on a steeek! :D Name: Mike Location: Windermere, FL Join Date: Feb 2009 Motorcycle(s): 2012 Harley Davidson XL883L Sportster Superlow Posts: A lot.	Oh it stretches, all chains stretch from use. I had to replace my cam chain in my 1994 last summer. The chain was $60, and the work was over to $600 because, like you said, the case had to be split open to get the chain off. __________________________________________________

May 20th, 2012, 12:53 PM	#4
alex.s wat Name: wat Location: tustin/long beach Join Date: Sep 2009 Motorcycle(s): wat Posts: Too much. Blog Entries: 5 MOTM - Oct '12, Feb '14	hmm... the tensioner seems to work fine... but it goes all the way out and the chain still has slack... to the point that it hits the case. im worried it will jump and i'll wind up smashing valves into pistons... what do you think the chances of that are, eric? i'm wondering if it will hold up for 3 practice sessions and a race... if it will i'll run them next week and tear it down after. if its risky then maybe i'll skip the race weekend __________________________________________________

May 20th, 2012, 03:32 PM	#6
alex.s wat Name: wat Location: tustin/long beach Join Date: Sep 2009 Motorcycle(s): wat Posts: Too much. Blog Entries: 5 MOTM - Oct '12, Feb '14	its a good thing engines are cheap and i have other bikes. anyone ever locked a motor on the track before? i've seen some videos. they make pretty cool crashes __________________________________________________

May 20th, 2012, 06:04 PM	#8
cuong-nutz RIP Alex Name: Cuong Location: Houston, TX Join Date: Apr 2011 Motorcycle(s): '10 250r, '09 265r Posts: A lot. Blog Entries: 2	Oh. Caca. How many miles do you have on your bike. __________________________________________________ HalfFast Racing Team Serving Greater Houston Area Riders:WFO Riders MotoHouston HPC CMRA Ride Smart Fastline Lone Star Track Days

May 20th, 2012, 04:41 AM	#2
Racer x ninjette.org certified postwhore Name: Eric Location: Iowa City Join Date: May 2009 Motorcycle(s): 2008 Kawmeracchi 350 2010 Project X Posts: A lot. Blog Entries: 54 MOTM - Sep '18, Feb '16	nope you have to split the case and lift the crank up to get the chain out. it goes around the crank and has no link. It is odd to stretch a cam chain. are you sure the tension er has not failed?

May 20th, 2012, 04:19 PM	#7
Racer x ninjette.org certified postwhore Name: Eric Location: Iowa City Join Date: May 2009 Motorcycle(s): 2008 Kawmeracchi 350 2010 Project X Posts: A lot. Blog Entries: 54 MOTM - Sep '18, Feb '16	My friend had a two strike lock up at over 100 mph. Quick clutch work saved it.. Yes if it's slapping that bad don't risk it. APE sells a manual tensioner for the 08 and newer.

June 11th, 2012, 09:42 PM	#10
CZroe CPT Falcon Name: J.Emmett Turner Location: Newnan, GA Join Date: Apr 2009 Motorcycle(s): '08 CP Blue EX250J, '97 unpainted EX250F, 2nd '97 unpainted EX250F (no engine), '07 black EX250F Posts: A lot.	My chain breaker has a cam chain pin and I saw a youtube video where someone replaced theirs on a dirt bike "the easy way" by splitting it, attaching to the new chain with a wire and turning the engine over until it came out the other side, preserving the timing. I'm still not sure how he connected the chain together without a master link of some kind.

June 12th, 2012, 09:24 AM	#12
alex.s wat Name: wat Location: tustin/long beach Join Date: Sep 2009 Motorcycle(s): wat Posts: Too much. Blog Entries: 5 MOTM - Oct '12, Feb '14	bike runs fantastic __________________________________________________

June 12th, 2012, 10:20 AM	#13
cuong-nutz RIP Alex Name: Cuong Location: Houston, TX Join Date: Apr 2011 Motorcycle(s): '10 250r, '09 265r Posts: A lot. Blog Entries: 2	Too lazy to re read but did the slack cause your motor to fail? __________________________________________________ HalfFast Racing Team Serving Greater Houston Area Riders:WFO Riders MotoHouston HPC CMRA Ride Smart Fastline Lone Star Track Days

June 12th, 2012, 10:35 AM	#14
alex.s wat Name: wat Location: tustin/long beach Join Date: Sep 2009 Motorcycle(s): wat Posts: Too much. Blog Entries: 5 MOTM - Oct '12, Feb '14	no. the chain isnt stretched. the noise seems to be from the chain guide itself tapping the cct. not sure why it makes noise but the chain is within spec. __________________________________________________

June 12th, 2012, 11:24 AM	#15
greg737 - Name: - Location: - Join Date: May 2009 Motorcycle(s): - Posts: A lot.	On the old gen side there have been guys who've measured their worn cam chain at various points and they discovered that cam chains almost never stretch (wear) uniformly. Instead the worn chain will actually be within wear tolerance measurement spec over some lengths of it and way beyond wear tolorance when measured at other points along the chain. This uneven wear sets up a "tight-loose-tight-loose" situation as the cam chain runs around across the cam gears and the engine gear. That's why it starts to make that knocking sound, and that's why it sometimes beats the cam chain tensioner to pieces. The cam chain tensioner is designed to absorb the relatively slow changes in cam chain tension (a "lash" effect) that are caused by normal engine accelerations and decelerations. The cam chain tensioner is not capable of dealing with the extremely rapid "tight-loose-tight-loose" high-frequency lash that an unevenly worn cam chain deals out.

June 12th, 2012, 03:29 PM	#16
alex.s wat Name: wat Location: tustin/long beach Join Date: Sep 2009 Motorcycle(s): wat Posts: Too much. Blog Entries: 5 MOTM - Oct '12, Feb '14	thats a good point greg. i measured it at a few points but really to be sure it should be removed. looking at the pins, they did look uniform and i couldn't see any stretching. but without measuring the entire thing it very well could be partly stretched. __________________________________________________

June 12th, 2012, 03:33 PM	#17
alex.s wat Name: wat Location: tustin/long beach Join Date: Sep 2009 Motorcycle(s): wat Posts: Too much. Blog Entries: 5 MOTM - Oct '12, Feb '14	its not an old engine and hasn't suffered any oil starvation so the only reason the cam chain would have stretched i think is if something got in there, or somehow the cam shaft locked for a second or something. i could see pregen cam chains stretching unevenly after sitting in the same spot for years with 50k miles on them already then start up and ran before changing all the fluids. but on a fairly new engine seems iffy __________________________________________________

June 28th, 2012, 01:57 AM	#19
Scattcatt ninjette.org sage Name: Zach Location: Michigan Join Date: Aug 2011 Motorcycle(s): 2008 Kawasaki Ninja 250R, 2003 Honda CBR600RR Posts: 721 Blog Entries: 1	Bringing this thread back to life. What exactly does this sound like? I ask because I've noticed a slapping sound in my engine for a while now too that just doesn't sound right. It kind of slaps for a few revolutions then stops for a few revolutions and the pattern repeats. I have not inspected anything yet as I've been reading through these threads to try and get an idea of what's going on. I have an 08 with just over 16k miles. Seems pretty low to me judging from these other high mileages I've read about regarding this issue. __________________________________________________ ATGATT

June 28th, 2012, 04:40 PM	#21
Scattcatt ninjette.org sage Name: Zach Location: Michigan Join Date: Aug 2011 Motorcycle(s): 2008 Kawasaki Ninja 250R, 2003 Honda CBR600RR Posts: 721 Blog Entries: 1	The drive chain as in the chain that goes to the rear wheel? Yes, this is the bike's 3rd one at minimum (bought it used with an aftermarket chain already on it, then I later replaced that one) __________________________________________________ ATGATT

June 28th, 2012, 06:52 PM	#23
alex.s wat Name: wat Location: tustin/long beach Join Date: Sep 2009 Motorcycle(s): wat Posts: Too much. Blog Entries: 5 MOTM - Oct '12, Feb '14	i'm just gonna go ahead and say no, it's a bad idea to cut and reweld your cam chain. will it work? if you do it perfectly. can you **** everything up in the blink of an eye? yep. now, if you had a proper cam chain press like i do... thats another story __________________________________________________

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