Tight Cams


16 replies to this topic
  • unclemd

Posted November 26, 2009 - 12:30 PM

#1

Installed Exhaust cam after valve adjustment and the cam is hard to turn now. Tightened to 10NM first and the cam can't be turned by hand anymore. Tried 9NM and it was VERY hard to turn by hand, then tried 8NM and it was still hard to turn by hand but was easier than any other torque. I used a couple different torque wrenches with he same result. I used engine oil to lube all contacting surfaces. What time of lube should i use. Any ideas would be appreciated. Intake cam turns freely (never had to adjust or remove).

Thanks

  • SXP

Posted November 26, 2009 - 12:49 PM

#2

Installed Exhaust cam after valve adjustment and the cam is hard to turn now. Tightened to 10NM first and the cam can't be turned by hand anymore. Tried 9NM and it was VERY hard to turn by hand, then tried 8NM and it was still hard to turn by hand but was easier than any other torque. I used a couple different torque wrenches with he same result. I used engine oil to lube all contacting surfaces. What time of lube should i use. Any ideas would be appreciated. Intake cam turns freely (never had to adjust or remove).

Thanks


I use 75 inch-pounds (~8.5 NM) which is about 11 inch-pounds less than the spec, and have not had any issues.

I'm curious how much the valves moved and how many hours/miles on the bike.

  • l_campionero

Posted November 26, 2009 - 01:05 PM

#3

You didn't accidentally reverse or switch any caps, did you?

  • unclemd

Posted November 26, 2009 - 02:23 PM

#4

Didn't take off the intake cam cover so i couldn't mess them up and they only fit one way. My mechanic told me i could use 8NM on it no problem but even then it didn't spin as free as the intake cam that wasn't touched. Do they loosen up when the engine has been ran through the heat cycle?

  • l_campionero

Posted November 26, 2009 - 02:25 PM

#5

If it's tight now, it'll probably stay tight. Was it tight before? Have you checked the clearance with a Plastigage?

  • unclemd

Posted November 26, 2009 - 02:28 PM

#6

No I have not, I don't have access to that type of tool. It was good before i took it off can't understand why its like that now. I only removed the cam replaced the shim and reinstalled the cam. Now i didn't use much oil around the journals would that make a difference?

  • l_campionero

Posted November 26, 2009 - 02:32 PM

#7

I would make ABSOLUTELY sure that everything is okay before starting it up. Plastigage is cheap and readily available:

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  • unclemd

Posted November 26, 2009 - 02:40 PM

#8

If i can find a Plastigage what type of reading am i looking for?

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  • CanadianWR450

Posted November 26, 2009 - 04:19 PM

#9

I think the "half clip" (my own technical term), behind the cam sprocket isn't in/seated right.
I had it happen to be...take it back off and double check that part.

  • unclemd

Posted November 26, 2009 - 04:30 PM

#10

When i seat the half clip in ti doesn't go all the way down to the cylinder head there is a gap on both sides. Not sure if it seats in all the way when i torque the bolts down. The cam turns fine when the two bolts closer to the sprocket are torqued down. The problem is when i torque down the two outer bolts(furthest away from the cam sprockets).

  • CanadianWR450

Posted November 26, 2009 - 04:37 PM

#11

Are you torquing them down following the proper procedure in the manual?
They need to be done in stages, and a proper sequence......

  • unclemd

Posted November 26, 2009 - 05:57 PM

#12

I'm torquing them in a criss cross pattern but not in a stepped manner. Would that make that much of a difference??

  • tribalbc

Posted November 26, 2009 - 07:04 PM

#13

I'm torquing them in a criss cross pattern but not in a stepped manner. Would that make that much of a difference??


Good chance

Any multi bolt item such as the cam caps should be first seated by hand in a criss cross pattern, then continue to slightly torque them up in that patern. If you torque one side with the other loose it will never seat properly.
You also want to make sure you first seat the cam cap cover by hand. Do not use the bolts to torque it into place.

  • unclemd

Posted November 26, 2009 - 07:10 PM

#14

Thanks for all the help everyone going to have to try a few things tomorrow. Looked at the head tonight seems that i may have nicked the edge on the head where the cam seats in when getting the shim out :excuseme: that my be my problem. Only nicked the corner may need a new head or is it worth to try to sand the nick out?

  • JDLowrance

Posted November 26, 2009 - 07:35 PM

#15

Definitely file down the nick in the cam journal. Get a set of jewlers files and only take off as much as needed to remove the high spot.

John

  • Thermos O flask

Posted November 27, 2009 - 02:49 AM

#16

I had the same problem after getting the head serviced...the donkey that did the valves rounded the edges of the bearing journals either side of the middle inlet valve,take out the buckets and see if it still locks up.This eliminates wrong shim's etc.I could actually see and feel the ridge,had to get out the wet & dry.
Runs fine now. :excuseme:

  • unclemd

Posted November 27, 2009 - 09:06 AM

#17

Just updating everyone i have the problem fixed. Found that i nicked the cam journal and had a high spot. Filed down the corner just enough to remove the high spot. Installed the cams and torqued to 9NM and they turned freely. Thanks everyone for the help with this problem.




 
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