Now you see it - Now you don't

I think this was addressed quit a while ago, but I couldn't find it in the archives. The last two rides I've started loosing radiator fluid. I'll fill the reservoir to the full line and by the end of a 30-50 mile run it will be at or below the add line. My riding area and habits have not changed. I drained the oil but could not tell if there was any coolant in it. I've not noticed any change in the bikes performace nor fluid leaking from the bike (other than the normal oil coming from the breather tube).

I don't know if this will help, but here are some specs on my bike and riding habits: RIDING HABITS - 1 to 2 times a week in the Arizona desert. About 4,000 miles on bike now. Was at Baja with Richard in March (see the "Stories" section) BIKE - '99wr400, air box lid off, FMF mega MaxII (uncorked), modified throttle stop, IMS tank&seat combo, applied top triple, Scotts Damper, maintained well (valves,linkage, oil changes, etc.)

Thanks for your help with this one.

It was Bryan's bike. He had a head gasket leak.

Yep Craig. Kevin has it. It was a head gasket leak. The bike ran fine and there was no coolant in the oil. But I had to top it off signifacantly before every ride.

I didn't replace the head gasket myself. And while my dealer was in there, I had them replace the rings for only a little more.


Thanks for the info. Bryan, were there any external visible signs of a leaking head gasket? Also, does anyone know what harm this could do to the bike (both short-term and long-term) if left unfixed? I have a ride lined up for tonight and tomorrow (and I know I can't get it fixed that fast) but won't go if it will hurt the bike.


I didn't see any signs of the leak. I have no idea where it was going. It didn't seem to be in the oil. And it sounds like I was loosing more fluid than you are.

I rode for three rides like that and replaced the fluid after each ride. However, I can't imagine that this is recommended. But the bike ran great!

My rides were in the winter though and the temp was only in the 50's.

The dealership charged me 300+ dollars to replace the head gasket and replace the rings.


[This message has been edited by Bryan (edited 05-22-2000).]

Removing the head is not a big deal. A couple of months ago Dirt Rider had a supplement mag attached to the months issue. It told step by step how to rebuild the YZ/WR top end.

I've had my cylinder off...again not a big deal. If you can handle the carb on these bikes you can do the top end. I would do the mechanical and leave the Mic and clearance stuff to a machinist. If you've done the timing change you were almost there.

I guess I could photo copy this for anyone and send it via mail or fax (pictures may not come out via fax).



86TT225, 98CR80, 99WR, WR timing, throttle stop trimmed, air box lid removed, White Bros head pipe, silencer and air filter. Odometer and headlight removed. Moose hand and mud guards. YZ stock tank and IMS seat/brick.

I know Bill. I should have done it myself. But I didn't want to deal with it and I tried to save time. Plus I didn't know for sure that this was the problem.

As it turned out, the dealership put my bike back to WR timing (I had YZ timing) and didn't tell me. Even after I TOLD them it was YZ timed.

I went for a ride and thought, where did the power go? I tore it apart and found their error. I put it back to YZ timing. I could have done it all myself and would have probably saved time and certainly a lot of money.


Bill, Bryan is it possible to post this Dirt Rider supplement in the tech section?

It sure would be nice to have that as a resource when it comes time...


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