Cool, so I put new valves in and then...


15 replies to this topic
  • bushy

Posted June 18, 2004 - 03:06 PM

#1

The freaking cam chain is caught on something. It will not have enough slack to go on both the cams, and turning the motor over back and forth does not break it free. Is there an easy way of getting the cam chain unbinded / free without taking the head off once again? The head gasket cost more then the valves.

This thing is gone as soon as its fixed.

  • Dirt_Boy96

Posted June 18, 2004 - 03:15 PM

#2

I have never tore down a YZF motor. Only 4-stroke dirt bike motor I have tore down has been an XR250R..but are you 100% sure that the cam chain is engaged on the primary drive gear? If not you won't have enough slack(on an XR250R anyways).

  • sirthumpalot

Posted June 18, 2004 - 03:23 PM

#3

Following on what Dir_Boy says, I believe you can see the lower sprocket if you pull the flywheel. Can someone verify this? Anyway, a flywheel puller is less than $15, grab one and take a peek back there and you should be able to see if it's on the sprocket correctly.

  • Satch0922

Posted June 18, 2004 - 04:05 PM

#4

silly question but I have to ask....did you remove the chain tensioner?

  • MXof21

Posted June 18, 2004 - 04:16 PM

#5

Odds are all you need to do is remove the flywheel and get a kink out of the chain.

  • FFRacing79

Posted June 18, 2004 - 04:33 PM

#6

Satch makes a valid question!

  • MN_Kevin

Posted June 18, 2004 - 10:05 PM

#7

pull the forward cam chain buffer pad,
pull up on the cam chain,
rotate the crank clockwise w/ a wrench,
keep the chain taught
and
re-insert the forward pad.

There is not enough clearance between the chain and the pad to roll out the links that are dangling below the crank sprocket.

Been there, done that. I worked for 3 days trying to figure that out. I thought I could just pull the slop out by rotating the crank. Can't >> need to pull the forward pad out.

  • bushy

Posted June 19, 2004 - 06:42 AM

#8

Thanks alot Kev, looks like you saved me 3 days!

Lets just hope the head gasket holds up if I reuse it.

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  • bushy

Posted June 19, 2004 - 06:42 AM

#9

Thanks alot Kev, looks like you saved me 3 days!

Lets just hope the head gasket holds up if I reuse it. Come on snatch, do you think a dummy :devil: :thumbsup:

  • Satch0922

Posted June 19, 2004 - 09:29 AM

#10

It's SATCH.....since you can't read I figured maybe you didnt take the tensior off....I know......Fruedian slip...... :thumbsup:

  • bushy

Posted June 19, 2004 - 11:47 AM

#11

:thumbsup:

Now theres a new problem. I have timed them the best of my ability and when the intake cam hits the intake valve and it is compressed all the way, it will go no further. Ive tried various times, the exhaust has no problem going around but the intake just stops.

  • MN_Kevin

Posted June 19, 2004 - 12:05 PM

#12

if it just stops, the intake must be out of time, or the crank is not aligned properly...right?

One thing I asked over and over and got the answer: When you set the timing marks, the ONLY mark that counts is the punch mark next to the "I" at the 3 o'clock position on the intake AND the punch mark next to the "E" at the 9 o'clock position on the exhaust cam. Both marks WILL align with the surface of the head.

(I would look at the other marks on the cam, and think well those others don't look right.)

Also be sure you are using the correct mark on the crankshaft. I installed a 450 cam last night on my '99. My buddy was aligning the wrong mark on the crank.

  • bushy

Posted June 19, 2004 - 12:08 PM

#13

It's the | mark, next to the H right?

If you can stay put for tonight ill have some pics of my timing in about two hours.

  • MN_Kevin

Posted June 19, 2004 - 12:12 PM

#14

yes, it is the "I" mark as you stated

  • bushy

Posted June 19, 2004 - 02:17 PM

#15

http://hs.enhanced-g...images/dan1.jpg
http://hs.enhanced-g...images/dan2.jpg
http://hs.enhanced-g...images/dan3.jpg

My cams look fine to me :thumbsup:

  • MN_Kevin

Posted June 19, 2004 - 05:03 PM

#16

Your timing marks do look fine. If the crank is lined up...I don't know... :thumbsup:





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