Is my wr450 cam timing off?


8 replies to this topic
  • shckonase

Posted October 26, 2015 - 11:29 AM

#1

I just recently shimmed the valves on my 2008 wr450 and noticed there were some discrepancies between the marks on the crank and the dimples on the cams when finding TDC. After lining up the marks on the crank (via the 2 engine caps), it needs just a little more rotation (~1 tooth) to line up the dimples on the cams so that they're flush with the head walls. The cams are timed right relative to each other but seem to be retarded ~ 1 tooth. 

 

I zip tied the cam chain to the intake cam before shifting it out of the way so It must have been done by the previous owner. Could this have been done intentionally? Are there any advantages or disadvantages? Or could it be that the cam chain is worn and should be replaced? I've only had the bike for 4-5 months and have put ~ 15-20k miles on it in that time. oil changes ~every 1-1.5k. It sees as much street as it does dirt.

 

 



  • shckonase

Posted October 26, 2015 - 11:33 AM

#2

Should add that It runs and drives just fine and I haven't had any real issues with anything thus far. mostly just curious as to why the timing might be the way it is, if that's common, not an issue, or worth adjusting. 



  • Krannie McKranface

Posted October 26, 2015 - 12:05 PM

#3

A worn out cam chain will do this

Are you checking with the tensioner appllied ?



  • bourneaussie

Posted October 27, 2015 - 05:23 AM

#4

I read somewhere, can't remember where, that the timing marks on the cam pulleys were manually punched in and apparently there can be a fair amount of difference of where it was punched compared to where it should have being punched.... Up to a tooth I read
To be honest even while I'm typing this I think it sounds like a load of shit but thought I would mention it anyway mate

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  • shckonase

Posted October 27, 2015 - 06:49 AM

#5

A worn out cam chain will do this

Are you checking with the tensioner appllied ?

I'm checking it with the tensioner off. The chain appears to be in good condition and tightens up nice with the tensioner. However I'm not sure I'd recognize, physically if it was worn.



  • shckonase

Posted October 27, 2015 - 06:53 AM

#6

I read somewhere, can't remember where, that the timing marks on the cam pulleys were manually punched in and apparently there can be a fair amount of difference of where it was punched compared to where it should have being punched.... Up to a tooth I read
To be honest even while I'm typing this I think it sounds like a load of shit but thought I would mention it anyway mate

hmmmm. I'd like to believe that's not true. something to consider though i suppose



  • shckonase

Posted November 02, 2015 - 03:07 PM

#7

Any other suggestions? The cam chain appears to be in good physical condition, tightens up as it should with the tensioner, and I do not hear any irregular noise from the valve covers so I don't believe the cam chain is worn out. 

 

I will be putting together a leak down tester pretty soon. so I should be able to compare results with it lined up to both of my TDCs. Although I suppose the valves'l seal up when its lined up to TDC via the cam dimples rather than the crank timing marks.

 

Any other Ideas as to why the cams are off? anything performance related? Maybe the previous owner or dealer goofed up when reinstalling the cams?



  • stevethe

Posted November 02, 2015 - 04:19 PM

#8

Cams won't be off a tooth. Your doing something wrong.

  • Krannie McKranface

Posted November 02, 2015 - 05:00 PM

#9

Any other suggestions? The cam chain appears to be in good physical condition, tightens up as it should with the tensioner, and I do not hear any irregular noise from the valve covers so I don't believe the cam chain is worn out. 

 

I will be putting together a leak down tester pretty soon. so I should be able to compare results with it lined up to both of my TDCs. Although I suppose the valves'l seal up when its lined up to TDC via the cam dimples rather than the crank timing marks.

 

Any other Ideas as to why the cams are off? anything performance related? Maybe the previous owner or dealer goofed up when reinstalling the cams?

 

Pretty scientific evaluation there !

 

The only way to know is to measure the distance between ten+ pins on your chain and a new one.

 

If it has 200 hours it's shot.






 
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