valve adjustment questions


9 replies to this topic
  • djo269

Posted July 29, 2005 - 09:15 PM

#1

I am in the process of adjusting the middle intake valve. A local dealer service manager said that my bike(2003 yamaha yz450f) has special titanium shims and that I should only replace those with alike shims. He told me that there would be some power loss if I were to use "universal" shims, shims that can be transferreable to any make or model. Is he right in saying this? I just dont want to wait for a shipment but I will if I really have to. As small as those things are I cant see how it would change the power. I also was curious as to know how bad it would be to have the timing chain come off the lower sprocket, is it hard to get put back on and will it throw everything off later? Is it ok to use motor oil in place of assembly lube? My bike may have to sit in the garage for a few days with the top end open and exposed to dust in the air and was wondering if it would be a bad thing to let it stay exposed for that long of a time? Is it ok to torque the cam cap bolts using your best judgement if you dont have a torque wrench? thanx

  • crfdude86

Posted July 29, 2005 - 09:44 PM

#2

how often should the valves even be adjusted??

  • grayracer513

Posted July 29, 2005 - 10:43 PM

#3

A local dealer service manager said that my bike(2003 yamaha yz450f) has special titanium shims and that I should only replace those with alike shims. He told me that there would be some power loss if I were to use "universal" shims, shims that can be transferreable to any make or model. Is he right in saying this?

Got a magnet? Time to stop talking to the guys at that parts counter. They're steel. Use any of them that fit.

I also was curious as to know how bad it would be to have the timing chain come off the lower sprocket, is it hard to get put back on and will it throw everything off later?

The engine is designed to prevent the timing chain from "looping" while it's being serviced. As long as you hold a little tension of the chain if the engine is being turned, it should stay put. If it drops a link, you won't be able to reinstall it, and you wil have to pull the flywheel and stator to get it back where it belongs. But that's not hard, and it isn't very likely, anyway.

Is it ok to use motor oil in place of assembly lube?

Yes, it's fine.

My bike may have to sit in the garage for a few days with the top end open and exposed to dust in the air and was wondering if it would be a bad thing to let it stay exposed for that long of a time?

Cover the engine up.

Is it ok to torque the cam cap bolts using your best judgement if you dont have a torque wrench? thanx

Absolutely, unequivocally, NO! It isn't. You'd be better off torquing the head by feel than the cam caps. Take $20 to Sears or a real auto parts store or some damn place and buy a 1/4" beam type torque wrench. Or, make plans to send your head to Engine Dynamics to restore the camshaft bores after you seize it. Torque the bolts up to spec in 3 steps.

  • FZ1426

Posted July 30, 2005 - 03:19 PM

#4

Just put the hotcams decompressor in my 426. I'm sitting here waiting for a Craftsman in/lb torque wrench to show up UPS. Somehow I've gotten through 20 years of aviation and not had to buy a torque wrench yet. It's the last thing to get here in my typical summer moto upgrade program. Did the Dr. D CR front brake line as well. With my well calibrated touch and a 12 point, 5" 8mm box end wrench, I know I could easily be comfortable with the torque value, but it's too damn hot to ride anyways so I might as well wait for the torque wrench and have that piece of mind goin' back together.
The hotcams is definitely a way different profile, more lift and less duration, I hope I'm not disappointed with the results, I was happy with the motor the way it was. Just looking for something to fiddle with. And trim some weight. :D

  • Yz4-me

Posted July 30, 2005 - 03:54 PM

#5

USE THE TORQUE WRENCH!!!!!!!!!!!!!!!!!!!! TO SPEC

i over-torqued my cam-tops by not using one, and it ended up costing me new head and cam not cheap, one cam actually ate into the head unitl my motor stopped running, the damage didnt look bad to the naked eye but it did the job.

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  • biznet1

Posted July 30, 2005 - 04:57 PM

#6

I am in the process of adjusting the middle intake valve. A local dealer service manager said that my bike(2003 yamaha yz450f) has special titanium shims and that I should only replace those with alike shims. He told me that there would be some power loss if I were to use "universal" shims, shims that can be transferreable to any make or model. Is he right in saying this? I just dont want to wait for a shipment but I will if I really have to. As small as those things are I cant see how it would change the power. I also was curious as to know how bad it would be to have the timing chain come off the lower sprocket, is it hard to get put back on and will it throw everything off later? Is it ok to use motor oil in place of assembly lube? My bike may have to sit in the garage for a few days with the top end open and exposed to dust in the air and was wondering if it would be a bad thing to let it stay exposed for that long of a time? Is it ok to torque the cam cap bolts using your best judgement if you dont have a torque wrench? thanx

Please don't take this the wrong way, but maybe you should find someone that you know to be a good mechanic to assist you through this. The questions you are asking imply that you don't have much mechanical experience. I'm definately no expert, but I've done enough to get myself into trouble enough times to know what NOT to try. Good luck.

  • DigilubeJay

Posted August 01, 2005 - 05:37 AM

#7

Somehow I've gotten through 20 years of aviation and not had to buy a torque wrench yet.

Please tell me that you are the wheel chock man, and not a mechanic. That is very scarey.

As grayracer and yz4-me stated, definately use a torque wrench on the cam bearings. They are the only set of plain bearing there is on the bike, and they need the most delicate precision handling of all the bike items. They will not withstand any sort of "by feel" torquing. They require precision.

I tend to disagree on motor oil being ok for assembly lube.
If you have nothing else, then by all means use it. But assembly lubricants are providing a concentration of things that protect at the barrier level. Barrier protection is when the simple film of an oil has been violated and additives must be in place to continue the protection. ie...during the mis-match of parts surfaces at break-in.
Many motor oils have small amounts of these barrier additives, but none have the concentration needed for proper protection during the break-in procedure.
Moly is one of the best barrier additives that can be used for break-in of parts, however moly in such concentrated amounts could possibly cause clutch issues on bikes.
Look for break in fluids with no moly or teflon.

  • grayracer513

Posted August 01, 2005 - 07:04 AM

#8

Moly is one of the best barrier additives that can be used for break-in of parts, however moly in such concentrated amounts could possibly cause clutch issues on bikes.
Look for break in fluids with no moly or teflon.

If you use an appropriate amount for the job (meaning a small dab only where it's needed), the moly in a pre-lube shouldn't be an issue. But it is a valid concern, so those of you who use assembly lubes, don't get crazy. Be careful, too, in using anything more solid than engine oil in the cam saddles, because the cold clearance is very small, and a badly placed blob of something pasty could possibly distort the cam caps.

  • FZ1426

Posted August 01, 2005 - 07:10 AM

#9

[quote name='DigilubeJay']Please tell me that you are the wheel chock man, and not a mechanic. That is very scarey.
:D Don't forget lav servicer. Funny.

  • DigilubeJay

Posted August 01, 2005 - 02:38 PM

#10

If you use an appropriate amount for the job (meaning a small dab only where it's needed), the moly in a pre-lube shouldn't be an issue. But it is a valid concern, so those of you who use assembly lubes, don't get crazy. Be careful, too, in using anything more solid than engine oil in the cam saddles, because the cold clearance is very small, and a badly placed blob of something pasty could possibly distort the cam caps.

I agree. An effective amount of moly shouldn't be of issue.
I bet an anyalisis of the first oil change on a new bike will show loads of moly from the factory build. But there again, the potential for clutch slip exists.
Best to find a non-solid break-in fluid for our applications.
They exist...hell I sell one of them.





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