HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
wardirt1

Cam Plug popped out-anybody seen this?

10 posts in this topic

I was riding my 2004 wr450 a couple weeks ago and my buddy noticed a quick puff of white smoke out of my bike. Later I noticed a small dripping of coolant from the radiator. Since I couldn't repair it right away and it was slight dripping and somewhat intermittent I did another 50 mile ride on it before I pulled the radiator off. When I did I noticed a plug missing on the cylinder next to the exhaust connection. From looking on-line I think it is a cap to access the cam chain. Has anyone else had this happen? Do you think I may have done any damage riding with it out?

Share this post


Link to post
Share on other sites

Does that cap hole have two small threaded holes next to it - one on each side? If so it could be your cam chain tensioner fell off. If so don't even start it.

Share this post


Link to post
Share on other sites

Sounds like the decompression plug fell out, common on 04 and older YZ/WR's

Do a search on that in the YZ forum.....easy fix:thumbsup:

Share this post


Link to post
Share on other sites

Sounds like you lost your deco plug. Where was the radiator leaking from?

Share this post


Link to post
Share on other sites
Does that cap hole have two small threaded holes next to it - one on each side? If so it could be your cam chain tensioner fell off. If so don't even start it.

Cam chain tensioner is located on the back of the motor. If that is missing I wouldn't start the bike either.

But from what you described sounds like the deco plug blew out which is located on the front of the motor above the exhaust header. Not a big deal. I bought one here on TT which I have never used. I just left the stock one in when I changed out my cam for one with auto deco built into it. I did pull off the deco lever and cable.

Share this post


Link to post
Share on other sites

I had the same thing happen to my 04'. I bought a new plug and added a little RTV Silicone to it when I put it back in. Never had another problem.

Share this post


Link to post
Share on other sites
Cam chain tensioner is located on the back of the motor. If that is missing I wouldn't start the bike either.

But from what you described sounds like the deco plug blew out which is located on the front of the motor above the exhaust header. Not a big deal. I bought one here on TT which I have never used. I just left the stock one in when I changed out my cam for one with auto deco built into it. I did pull off the deco lever and cable.

Yall are right. :eek: Those decomp plugs are known to pop out. Installed one I bought from TT as well though mine hadn't popped out. Had to take off the valve cover to knock it out. It did take me another swig from my beer to accomplish this.

Share this post


Link to post
Share on other sites

thanks folks, it was the decompression plug. I figure I put 40 miles on it the day if popped out (after it popped out) and another 35 of dusty single track on the next ride before I discovered it. Looks very clean inside the passage way but it obviously spit out oil. Ran great to the end although it seemed to stall out a bit more frequently. There was a great thread on TT about it, hoping I did not do any damage. I am assuming the + pressures have kept me out of trouble. I am thinking that when it blew out, it damaged the radiator, can't think of any other cause for small leak and the timing is right but have not had it pressure tested yet to isolate the leak.

Share this post


Link to post
Share on other sites

check and see if your breather hose is pinched, I removed my bracket to keep this from happenning and used a zip ty instead . I have personally seen this happen twice due to this. then buy the plug from thumper talk store. It's held in by the screw previously used to hold the decomp lever.

Share this post


Link to post
Share on other sites
check and see if your breather hose is pinched, I removed my bracket to keep this from happenning and used a zip ty instead . I have personally seen this happen twice due to this. then buy the plug from thumper talk store. It's held in by the screw previously used to hold the decomp lever.

I pinched my breather between my skid plate and frame once. After about 20 miles I noticed a bunch of oil spray on my left boot. My riding boots. I stopped and took a look and sure enough I had blown the top end rubber gasket off the left side of my motor.

I was totally freaked out but with some small flat blade screw drivers and a little oil I did finish the ride. Still use the same gasket to this day. It really was no big deal. But to this day I always check that thing.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0