Jump to content
Sign in to follow this  

06 yz250f cam trouble....

Recommended Posts

I just recently bought a used 06 yz250f from someone that said that "just adjusted the valves". When I first got it I had to change the jetting a bit because he had it too rich. After I put in the proper jets the bike was running perfect. It started on the first kick most of the time hot or cold. It was making good power and sounded fine. Yesterday I was going to go for another ride and I took off down a hill and bump started it since I was coasting and it started right up. I gave it a twist and it took off then all of a sudden the motor just died and it locked up the rear wheel ( which almost made me crash). I tried to restart it for a while. It started a few times but only when I held the throttle open a bit like it was a 2-stroke but it would not idle. I opened it up today and noticed that the intake cam wouldn't move. I pulled the cam and noticed that the right cam saddle (opposite from the bearing) was messed up and worn like if it got hot there and melted a bit. It isn't too bad but its enough to cause the cam to not move freely. I am not sure what may have caused this. I was thinking that it could have been either the guy that put it back together didn't do it right or over-torqued the cams or it wasn't getting any oil to that one spot. I would really appreciate any input or advice. Will I be able to fix the head and cam cap or is it trash? I'm hoping to get this fixed soon so I can ride again. Thanks.

2010-03-29190831.jpg

2010-03-29190917.jpg

2010-03-29190857.jpg

Edited by skyrider1977
Adding pics.

Share this post


Link to post
Share on other sites

it can be fixed.

engine dynamics. on the non-active volcanic side of the us (ie east of you).

maybe someone on the islands does it as well?

and yes either over torqued or no oil.

i'd bet on over torqued.

Share this post


Link to post
Share on other sites

Now that I think about it, when I did an oil change after I got the bike there was a bit of alum flakes in the filter. At the time I didn't really think to much about it. But I guess if the guy over torqued it that it was wearing the whole time until it decided to stop.

Share this post


Link to post
Share on other sites

Unfortunately it is very easy to over torque the cam bolts. It only requries 7 ft-lbs of torgue . I think I can use my fingers to achieve 7 lb.s

Share this post


Link to post
Share on other sites

I dropped the head off at a machine shop today and they said it would be about $150 to fix it since they need to pull the valves out to do it properly. I noticed in the book that the torque for those bolts says 7.2 fl-lbs or 86.4 in-lbs. Would it still work fine if I used a little less torque? Also, is there a special sequence I should tighten them in? Like start in center or star pattern or anything like that? I don't think the book says anything about it....

Share this post


Link to post
Share on other sites

that doesnt look bad at all.

150 seems a bit much for as little damage.

yes, there is a pattern and yes it is in the book.

and i do it in 3 steps. 40,60,85 in-lbs

the flakes are from the clutch basket. NOT the head.

double check the oil lines.

when did you last check the oil screen on the oil pump inside the motor?

Share this post


Link to post
Share on other sites

I checked the oil screen thats inside the oil tank on the front of the motor. That was clean. I guess since I'm waiting on parts I could look a bit deeper. I left the book at the machine shop so they would have the specs when they torque it to make sure its good. I'm assuming that I should be able to check the oil pump screen without pulling the motor apart. Is this correct?

Share this post


Link to post
Share on other sites

you can check the oil pump screen if you are an octopus or a squid or have eye stalks like a snail.

or are really good with a bendy mirror and a flashlight.

obviousally it gets a complete cleaning when you replace the crank when the cam gear becomes worn.

over torquing is SO easy on these.

a really good in-lbs torque wrench is critical.

Share this post


Link to post
Share on other sites

Hi, so its over a year since your repair. Does it hold. I just had the same problem this week, and want to know if you found what was the problem?

Share this post


Link to post
Share on other sites
Hi, so its over a year since your repair. Does it hold. I just had the same problem this week, and want to know if you found what was the problem?

Yeah my bike is still running like a champ. I haven't had any problems with it at all. I love it. 🙂

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

Reply with:

Sign in to follow this  

×
×
  • Create New...