Jump to content
Sign in to follow this  

Head gasket? Or water pump?

Recommended Posts

2002 CRF450R...not that it really matters, but just in case anybody was wondering. 

 

Start the bike up, blip the throttle to high rpm and coolant spits out the overflow tube with great pressure.  Blip it again, and it again shoots out coolant.  I tried the radiator cap from my other CRF450R, and it still spit coolant out.  Put the first cap on my other bike, no spitting of coolant.  

 

I have a small drip from the weephole under the impeller.  

 

The million dollar question:  Can a failed water pump cause the coolant to spit out with great pressure?  Or only a head gasket failure?  Do I have both problems?  
 

I haven't noticed any coolant leakage prior to this.  The bike starts fine, doesn't seem to have a loss of compression, but I haven't compression tested it to be sure.  

Share this post


Link to post
Share on other sites

Wouldn't your bike be blowing clouds of white smoke if it blew a head gasket?  But yeah, do a compression check first.

 

Maybe you need a new cap?  I'm thinking if the cooling system isn't pressurized and circulating coolant properly, it pushes open air and spits coolant out the overflow tube?  I'm no master mechanic though.

Share this post


Link to post
Share on other sites

Interesting. 

Excessive coolant pressure and discharge out of the pressure cap is usually from a leaking head gasket.

Water out of the weep hole is a leaking water pump seal.

 

So you got two for one.

Edited by Chuck.

Share this post


Link to post
Share on other sites

I was kinda afraid it would be both....great.  I had just got the carb back from Zip Ty Racing, had them do the whole mod and service thing.  Started the bike up (which it started great, by the way) and then the coolant starts puking all over the garage floor.  I was really looking forward to test riding it today, too!  Oh well....would a leakdown test be a sure fire way to see if the head gasket is bad?  I should probably buy a test kit anyways....

Share this post


Link to post
Share on other sites

I have a 03 crf 450. Same as 02. I don't ride it anymore Have a 12 yz450. But have to much n the crf to get rid of it. Had the same problem with the weep hole. Changed the seal. Didn't help. Changed both water and oil seal. Didn't help. Ended up changing shaft and bearing to. So when u get n to it. Change it all save the headache. And I'm surprised u haven't had problems with the valves yet. I ended up putting kibby white valves and springs. Never had a problem again with the valves

Edited by Jdrost72

Share this post


Link to post
Share on other sites

I've got an APE head on the the one bike, with stainless steel valves.  The other bike has some aftermarket valves, but not sure what they are.  Had an 04 250X that had the valve problem....never again.  Sometimes, aftermarket IS better than OEM!

  • Like 1

Share this post


Link to post
Share on other sites

UPDATE:  Replaced the head gasket and the problem went away. (Rebuilt the water pump at the same time as well.)  All's good now, bike runs like a champ again!

Share this post


Link to post
Share on other sites
APE does. APE will do just about anything you want (also known as Bigborethumpers)[/quote

I meant stock. Kibby white makes them

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  

×