Kawi2strokes.com Forum

When I went to the Gap (Dragon) I noticed some water on the cyl's after a ride. The coolant level was high in the water tank so I just sucked some fluid out and thought it was fine.

I was checking out my bike since I took the comp. check. I noticed the coolant level was just below the low line. I ran the bike for a short distance and after letting the bike cool the coolant in the water tank was now empty.

Today I filled the water tank to the bottom of the word coolant on the tank. I went for a run and rode somewhat hard. The highest the Temp. came up was below 3/4 and this was when I had to stop for a vehicle. When starting to ride again the temp. went down to just above 1/2 way. I drove home, jumped off the bike and the level was now at the full line. I let it run in the drive way for a few minutes and then noticed the level comming up quickly.

It then puked out the top of the cap. I shut down the motor. After cooling the level is now at the low level line.

What is the problem? What should I check first??

Stock radiator, new water pump, 50/50 coolant mix.

Thanks for any and all help in advance.

Note; The Bike ran fine, felt great.
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Iron on the Bayou.
84 RZ-350
1st over, stock porting, cylinder internals cleaned up only. Stock carbs, origingal V-Force Reeds and spacer with Y boot and K&N filter. Spec 11 pipes. Head milles .020

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Iron On The Bayou.

Iron, that part makes it sound like when you drove home with a hot engine and let it idle, it boiled some coolant, which would make the tank appear to fill quickly as the steam in the engine pushed coolant out. Then when the engine cooled back off, the level went to back to the "true" level.

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If it surges, that's normal, upshift.

look at an english language forum about RZ or RD LC 250 350.
The water pump trouble is well know on those bikes

I have a post out on the RZ Forum. No reply at this time.

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Iron On The Bayou.

Did the fan come on when you let it idle in the driveway? (or doesn't an RZ have one?)

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If it surges, that's normal, upshift.

No fan on the RZ at least from factory Jim. I have an electric fan from an R6 ordered to make this upgrade on mine and will trigger it with a manual override rocker switch. RZs can tend to run alittle hot even when stock. Mark- I hope it's not a blown head gasket. Guy on RZ board mentioned trying a different rad cap. Have you rechecked the head bolt torque values?

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1972 Kawasaki H2 Mach IV (Candytone Blue), 1976 Suzuki GT750 (Maui Blue)
1984 Yamaha RZ350 (KRR- Yellow/Black).

“Jeff and Chris are THE MEN!”
RIP John E. Evans

No Jim, no fan.

Mr. Ward, 10-4 on the Radiator Cap. Retorque was done.
You have a PM.

Thanks everyone.

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Iron On The Bayou.

Mark,

Since the engine is not running too hot that means the water pump and radiator are working. The radiator cap is also functioning since the coolant level is varying in the over flow tank. The radiator cap allows pressure out to the overflow tank when the system pressure exceeds 12.8 PSI and when the system pressure drops below atmospheric pressure there is a check valve that opens allowing the coolant to be pushed back to the radiator by the atmospheric pressure. Now that cap may opening too late under pressure or the check valve is not allowing the system to "equalize". See if you can check the radiator cap. But buddy it may be engine compression getting into the coolant system. See any of that good old hydrocarbon stuff you like so much is floating around in the coolant?

The girly biker...

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1973 RD350, 1979 RD400F, 1984 RZ350, 2014 Suzuki Vstrom 1000
CHRIS AND JEFF ARE THE MEN

Another thing Mark, be sure that tiny hole in the overflow tank cap you ask me about is not stopped up. If that hole is not opened to the atmosphere the system will not equalize.

Now this is a girly biker. I wonder what she is thinking about?...Oh, I bet she is thinking about how much she'd like to ride my RZ instead of that old farinorous triple

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1973 RD350, 1979 RD400F, 1984 RZ350, 2014 Suzuki Vstrom 1000
CHRIS AND JEFF ARE THE MEN

Just try to find a hot gal pic with a RZ... just try.... it ain't gonna happen....... She is there because triple are HOT bikes....

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Twist the throttle, tilt the horizon, and have a great time. What triples are all about...........