Jump to content
Sign in to follow this  

13 CRF450R coolant issue?

Recommended Posts

Just trying to confirm what I think is the issue.....all coolant is expelled from radiators through relief tube within a short time of riding.... the cooling system is creating excess pressure causing coolant to blow out tube. Changed radiator cap- no fix, water pump is working, radiators are not damaged.....no coolant in oil.

 

Head gasket.... Right?

 

Thanks,

Share this post


Link to post
Share on other sites

It does sound like a head gasket problem, before tearing into the engine you should pressure test the cooling system :

j-24460-a.jpg

Share this post


Link to post
Share on other sites

Less likely but a cracked cylinder or head.

 

Inspect the spark plug, there is likely coolant deposits on it.

Edited by mlatour

Share this post


Link to post
Share on other sites

Did you properly bleed the system and use properly mixed coolant ? Put the radiator cap on properly..... ?Just saying because you never know. Coolant cap takes one twist then normally takes one small little extra twist then it's properly seated

Btw there's no overflow tank on dirt bikes so if you fill it perfectly it will leak out as the coolant itself expands. Ride , till bit of coolant comes out , let cool then ride again and see if it still comes out .

If it's head gasket or crack you would very likely leak in to the engine as well and generate white smoke

Share this post


Link to post
Share on other sites

To OP,

forgot to ask, do you mostly slow / trailride/ off-road this bike or rather ride at a faster pace / motocross ?

 

If applicable, on slow  tight trails since a reduced airflow is moving thru the radiators it's quite normal that it overheats / overflows coolant.

Edited by mlatour

Share this post


Link to post
Share on other sites

Bike runs great & radiator cap was changed, didn't correct problem.

I ride B class, vet rider, motocross...so air flow not an issue. I can make 2 laps at the track and my buddy saw it spew coolant/steam out the overflow tube while on the gas hitting a jump.

It may be a cracked cyl too?? I'ma tear it down tomorrow after i test cooling system. Hope it's just the head gasket, cheap fix!

Share this post


Link to post
Share on other sites

Keep us posted, take some pics of what you find.

 

Cracked cylinder or head is a very rare occurrence, don't worry about it

more likely happens when a bike was left out in freezing weather without the proper antifreeze concentration.

Share this post


Link to post
Share on other sites

Did you properly bleed the system and use properly mixed coolant ? Put the radiator cap on properly..... ?Just saying because you never know. Coolant cap takes one twist then normally takes one small little extra twist then it's properly seated

Btw there's no overflow tank on dirt bikes so if you fill it perfectly it will leak out as the coolant itself expands. Ride , till bit of coolant comes out , let cool then ride again and see if it still comes out .

If it's head gasket or crack you would very likely leak in to the engine as well and generate white smoke

x2 on making sure you properly bled the sytem by rocking the bike side by side. Do it til the fluid drops. 1-2 times or more and top off.

Share this post


Link to post
Share on other sites

Thanks everyone for the input! 

 

Yeah I bleed the system, the plastic plug on top of the left radiator makes it pretty easy.

 

The cooling system is getting pressurized, bike's not "overheating" causing the issue...it's gotta be the head gasket (i hope). I did the top end months ago, I shoulda used the OE head gasket but went with aftermarket kit "cheaper".....

Share this post


Link to post
Share on other sites

Normal, if it's not visibly leaking externaly, it must be leaking internaly (in the combustion chamber),

once the engine is running the combustion pressure is perhaps then over-pressurizing the cooling system pushing the coolant out the overflow tube.

 

Take a good look at the head gasket it will likely show if/where it is leaking from.

 

Has the engine ever overheated?

If yes it would be wise to have the cylinder and head mating surfaces checked for trueness.

 

Post a few clear pics of the head gasket.

Edited by mlatour

Share this post


Link to post
Share on other sites

Haven't over heated to my knowledge....didn't notice a performance problem.

 I'm pretty sure that the cheap head gasket is the culprit to this issue. I'll post pic of gasket this evening when I get it fully disassembled.

 

Thanks, 

Share this post


Link to post
Share on other sites

The engine's oil is likely contaminated by coolant as well from sitting on the piston and making it's way down the bore.

consider doing a drain / refill to flush out any contaminants that might be in there (no need to spend on expensive oil, Rotella is fine)

Drain the oil, refill and run up to operating temp, drain it again (inspect that there is no signs of coolant), refill.

 

I'm not familiar with Honda (or for that matter 4T's in general) but from the gasket picture I notice there are only 4 cylinder head bolts on that 450?

My little YZ125 has 5, a YZ250 has 6. Only 4 doesn't seem much to spread the clamping force evenly.

Edited by mlatour

Share this post


Link to post
Share on other sites

I'm not familiar with Honda (or for that matter 4T's in general) but from the gasket picture I notice there are only 4 cylinder head bolts on that 450?

My little YZ125 as 5, a YZ250 has 6. Only 4 doesn't seem much to spread the clamping force evenly.

4 strokes utilize long bolts that reach from head through the cylinder and into to cases. They are plenty strong to keep things together. Your 2-strokes have the cylinder bolted down separately where 4 strokes don't.

Share this post


Link to post
Share on other sites

Thanks, Yeah, live and learn. Won't be in doubt in the future. Major difference in OE head gasket vs aftermarket. OE has three layers of gasket, aftermarket only two layers!

 

I plan to flush motor well before assembly, however I had no sign of coolant in oil when I drained. There's a small visible area on piston and head where the coolant was entering combustion chamber....I cleaned that up!

 

Thanks for the input!

 

2013 CRF450R B&W3.jpg

2013 CRF450R B&W.jpg

Edited by Bazzurk
  • Like 1

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...