FZR400 guys: F3 rad v. FZR60 rad

Seriously, the thermostat thing totally cured my problems. Just make sure you warm the bike up a little while before you hit the track.

 

Sorry I wasn't able to reply sooner.

Scott has hit the nail on the head gasket.

You most likely have a head gasket problem.

If the motor was built by Brian Conley of Valley Racing in Beacher Ill. then you have had the best in the business build it.

I do not recommend running without a thermostat. If you have to run without one then you are most likely masking another problem altogether.

Getting a good seal on the head gasket is a challenge to begin with and when racing an FZR it can have a problem at anytime.

If the motor was fresh and you didn't re-torque the head after the first few heat cycles or break-in period then it's more likely to become a problem soon then later.

Don't worry though! This is nothing to kill yourself over. It's not that big of a deal to replace the head gasket.

Use Scotts procedure in checking to see if the bike pushes water (which is sounds like it's doing).

A lot of times the head gasket leak is so small that it only occurs at high rpms so it's sometimes difficult to diagnose. You can run the bike in the pits, get it up to temp and not see the problem. You can pressurize the cooling system and not find the problem. You can turn the bike upside down and inside out and not find the problem. Put it on the dyno or on the track and you'll find the problem.

I've been at races before and had a head gasket start to go. Sometimes the leak was so minimal you could run an 8 lap race and not push water to point of overflow but sooner than later you'll be spewing like you've been out all night drinking Goldslogger.

 

Great...

Oh, I know that a head gasket isnt' that big a deal, but if you knew my history of trying to get on the track on a bike that is working over the last year, you'd feel my pain

The motor was built by Valley, and it doens't have much time on it...I think Lee raced it 3 times, and I've raced it 3 times...and it was acting exactly like it's acting now when I got it. My first time riding it was in Novemeber at Nashville last year. The ambient temp outside was about 52f, and the operating temp of the bike was 209 or so, and it was spitting coolant on the last lap of the race I ran.

Anyway, I'm gonna check it all out over the course of this weekend, and I'll know what's going on. Thanks for the great info!

 

Great info!

 

You could try to re-torque the head and see if any of the nuts move. I'm not sure it will re-seal the head gasket (I've never been lucky like that) but at least you'll know if it was a problem and who knows, maybe you will get lucky.

To re-torque the head with the motor in the bike you'll need a allen socket that will reach the nuts but not be so long that it won't allow room for the torque wrench.

I bought a long allen socket and then cut it down so that the length of the allen tool is 3" to the bottom of the socket.

You have to take it off the wrench for the two nuts on the rear far outside. drop it down into the nut and then put the wrench back on and torque.

There are holes in the cams that need to be aligned with the access holes (remove the rubber plugs) in the cam caps to get the tool down to the nuts. You align them by turning the motor over by hand. Use a 14mm wrench on the end of the crank at the ignition/pick-up side under the timing cover.

Follow the torque pattern in the service manual.

Maybe Lee never re-tourqued the head after break-in.

 

I must have built at least 10 FZR motors (4 and 6) for myself and others and never once had an issue with an OEM head gasket sealing.

 

Are you trying to help here or just tooting your own horn?

 

Jason, I little off topic here. But when are you going to race the "Bullet Fizzer" again. I loved seeing that little hot rod tearing up Road Atlanta.

 

Thanks for that insightful commentary. You are clearly the world's best FZR assembler, ever, and I shall take this new found inspriation with me wherever I go.

 

Ya know, I'm not sure, probably will run it a few times this season for fun. I love the bike and it's still fun as hell to ride.

Don't think it will see Road Atlanta this year though.

 

I'm just stating that in my experience, I don't think that there is a problem with OEM gaskets.

However....YMMV

 

My point was not to pat myself on the back, but to point out that in a sample size of 10, there were no head gasket related issues. Even with engines up to 13.5:1 compression.

Since the engine has to come apart to evaluate the head gasket, sometimes it might be prudent to look at all the external potential problem before pulling the head.

Things like
stuck t-stat
air in system
water pump
air/fuel ratio
timing

But I guess you'd rather just jump in at the deep end and be a sarcastic prick from the word go.



edit: shouldn't post when pissed

 

Good suggestions on eliminating things that may cause a similar symptom - running hot.

Problem is he's not just running hot, he's pushing water (from what we're being told).

Good suggestions though!

 

WERA Nationals at Barber. Come on down and kick some SV butt in F2.:up:

 

Pushing water = time to yank the head

Flycut it and the cylinder block as lightly as possible to clean up the gasket surface and any unevenness.

Go again....should be GTG after that

 

Thanks for the info...I was unable to guess at all of the above information based on your "I've never had any problems" post.

 

I'd love to but with gas prices what they are today I could probably race two weekends around here for what it would cost to tow there and back

 

I'll throw in the first hundred for gas if you change your mind.

Probably get you some free passes to the museum also.

 

Alright now, cut that out!

 

Seriously, it would be worth it to watch the SV guys cringe as that little rocket flies past. And, if you never done Barber, you owe to yourself.

Same offer for the GNF also. :up: