2007 450 exc. over heating

I recently purchased a 450 exc. and continue to have overheating issues. I installed engine ice and deleted the thermostat with no results. Does anyone else have this problem

Have you tried a JD Jetting kit? Stock needle is really lean.

No I haven't. You think I need a larger jet?

I recently purchased a 450 exc. and continue to have overheating issues. I installed engine ice and deleted the thermostat with no results. Does anyone else have this problem

Is this your first KTM RFS 4 stk ? If it is, here's couple basic things to watch for.    Keep the coolant just barely above the fins in the rad, make sure you've bled all the air out of the system, bleed ing the head first, then the right side rad. Keep the bike level while checking and bleeding . 

 

My '06 450 EXC came without a fan kit, does your '07 have the fan? If not, I'd install one. The factory kit is plug and play, very easy to install. I also installed a CRT on my bike.  It probably didn't need it,, but I had it from another bike I'd owned.

 

I'd check and perform the basic stuff first, then do the JD jet kit. (Mine has the JD jet kit)

 

Good luck with it.

 

RB

I recently purchased a 450 exc. and continue to have overheating issues. I installed engine ice and deleted the thermostat with no results. Does anyone else have this problem

How long does it take to overheat? Whats the temp u riding in currently.?

We see this topic come up all the time. Before you start changing things, you have to diagnose the problem. Do you have a cooling system issue? Is it a jetting issue? Is it something else. Until you know that, you are just stabbing in the dark.

 

By far the most common reasons for overheating on older RFS bikes are in this order:

 

- Bad radiator cap, they go bad all the time

- Jetted too lean, or clogged jets

- rider caused, too tall of gearing, over use of the clutch etc.

 

A properly tuned KTM typically does not need to have any part of the cooling system modified.

 

 

A properly tuned KTM typically does not need to have any part of the cooling system modified.

 

Very true, but a fan is still essential when riding in slow moving grueling conditions.

 

 

A properly tuned KTM typically does not need to have any part of the cooling system modified.

 

Very true, but a fan is still essential when riding in slow moving grueling conditions.

If you have too little airflow its gonna blow steam , which is not always indicative of overheating , a crt is good along with a fan ,and jetting.

I do have a fan installed I am on kauai,Hawaii all of the riding I have found so far is slow and tight. The ambient temp is typically high 80 low 90's

What is a CRT?

We see this topic come up all the time. Before you start changing things, you have to diagnose the problem. Do you have a cooling system issue? Is it a jetting issue? Is it something else. Until you know that, you are just stabbing in the dark.

 

By far the most common reasons for overheating on older RFS bikes are in this order:

 

- Bad radiator cap, they go bad all the time

- Jetted too lean, or clogged jets

- rider caused, too tall of gearing, over use of the clutch etc.

 

A properly tuned KTM typically does not need to have any part of the cooling system modified.

I'm suspicious about my radiator cap. It seems system is under higher pressure, every now and then leakage from the water pump appears even thou the seals are brand new. Should I buy new cap?

I do have a fan installed I am on kauai,Hawaii all of the riding I have found so far is slow and tight. The ambient temp is typically high 80 low 90's

What is a CRT?

Coolant return tank:  http://rlrproducts.com/index.html

 

I run in similar temps on the same bike with a CRT and KTM fan and I've yet to overheat even on really slow and technical singletrack.

I would bet your gearing is to tall, 14/52 or 13/50 will keep you from slipping the clutch and creating heat.

Next you may be overfilling your radiators, only fill to the top of fins or it will blow out no matter what.

Last you need to get the JD jet kit and run it just a hair rich. This bike is real lean with the stock jets.

Don't let it sit and idle, if you stop shut it off, you just create more heat by idling it.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now