450 overheating

[eric450r]

i just bought a 09 ds450 and ran 2 races and it overheated both times. i like the quad and am doing well on it except it is over heating. does anybody make a bigger radiator or anyone else have this problem?

[florentino]

Originally posted by eric450r
i just bought a 09 ds450 and ran 2 races and it overheated both times. i like the quad and am doing well on it except it is over heating. does anybody make a bigger radiator or anyone else have this problem?

drain all the green antifreze then put engine ice.. also put inline cooler and cut some holes in the plastics.. make sure your fan is working, i hot wired mine to stay on at all times. after that i was fine

[Mr. Big Time]

You can take your radiator out and send it to motoworks and for $100 they'll take drill a hole in the top and weld on a cap then you can eliminate the overflow tank, however, then you have to buy new hoses which they also have. You can also drill holes in the plastic and put heat tape on the gas tank, over flow tank, and oil tank. Then find a set of louvers. Theres a carbon company that makes some...I for got the name :D

[jlrenken]

mr bigtime can u send a pic of the rad cap.

[Mr. Big Time]

sorry, but I have not had that done to my bike yet, but if you call motoworks I'm sure they'll email you a pic. It helps alot from what they tell me, and they spend hours and hours testing. So they are definetly people I would trust on anything about the bike.

[Co_Racer]

If you have overheating problems you have something wrong don't go moding the cooling system it may not fix it. My son and many other race Ds 450 at New England ATV races we are now in round 5 this weekend and no one haveing overheating problems at some races he run 2 class 4 stroke B and College Boy and run moto all most back to back and has had no overheating problems have even had it hookup to b.u.d.d. buy the BRP race surpport at your races and PC check shows it has never got hot. So check out your cooling system the stock cooling system is just find when working correctly

[ScottB125]

There seems to be several that overheat. I don't push mine as hard as a pro, but do ride in 100* heat here in Texas without any issues.

Its not leaking coolant anywhere?

I know when I added a pipe, mine started running alot hotter. I only heard my fan come on once. Now it comes on everytime I ride.

[maconu]

If you have a number plate on a BRP race front bumper it is blocking airflow to the radiator that is right behind it. I had this problem when I first got the bike last year.

make sure your overflow tank has the right level of fluid in it. There are 2 lines across the overflow tank towards the bottom. If you are below the lower line this may be your problem.

I over heated recently and was a little low on coolant. I opened the overflow tank and ran my bike for 8ish minutes. Near the end of that run a large airbubble came out. I filled the overflow tank to the top line and since then I have been good.

If everything else on your bike is working something above should do the trick. If you want to permanently get rid of limp mode do this:

Purchase another thermostat and zip tie it to the frame. Unplug the thermostat sensor and plug it into the new thermostat. At that point it obviously won't go into limp mode because it never gets anywhere near the limp mode temp since the thermostat isn't in the bike........ The downfall is obviosly... it never thinks the engine gets hot so you could do some irreparable engine damage.

I do have one question on that last thing though.... Does the ECU read the engine temp and change how it handles fuel?

I noticed that after I did the thermostat my bike is popping more, either that or I'm noticing it more.

[ScottB125]

On tricking the ECU, you could splice in a resistor and not have to buy the extra parts.

I'm wondering if alot of people don't have air trapped in their system. These bikes may be bad about that....some cars are. Its hell getting all the air out sometimes.

[maconu]

I've also noticed, thanks to Tom, that the over flow return line on the right side of the bike is routed across the top of the fuel tank and could be sitting higher than the overflow tank so air would have a tendancy to hang out there instead of into the overflow tank. I just made sure I was holding the line down when getting the air out of the system.

[HOBS DS450]

Originally posted by maconu


I do have one question on that last thing though.... Does the ECU read the engine temp and change how it handles fuel?

I noticed that after I did the thermostat my bike is popping more, either that or I'm noticing it more.

Not familar with Can Am's programming but I would say yes. Most likely fuel and timing.


You should start running some better fuel too.

[TNT]

Originally posted by maconu
If you want to permanently get rid of limp mode do this:

Purchase another thermostat and zip tie it to the frame. Unplug the thermostat sensor and plug it into the new thermostat. At that point it obviously won't go into limp mode because it never gets anywhere near the limp mode temp since the thermostat isn't in the bike........ The downfall is obviosly... it never thinks the engine gets hot so you could do some irreparable engine damage.

I do have one question on that last thing though.... Does the ECU read the engine temp and change how it handles fuel?

I noticed that after I did the thermostat my bike is popping more, either that or I'm noticing it more.

If you look at the wire diagram there is an input for the Coolant Temp Sensor (CTS) and air temp comes from AAPT(Temp)S to the ECU. I’d assume that the ECU adjusts fuel delivery based on both, the AAPTS more to determine the density of air. It’s programmed to take in values from all the sensors go to table and output a fuel delivery. The fuel delivery will be such that the ratio of air-to-fuel is based on all the input parameters is close to 14.5 parts air to 1 part fuel, so in that respect the ECU is keeping the engine from getting lean or hot, but it’s ability to keep the engine from overheating is limited hence the limp mode.

Many factors outside the system design can cause a overheat mode such as a clogged radiator, leaking or low system pressure, faulty sensors or pump, etc…..The thermostat if I remember correctly (don’t have my manual w/me) gets it’s signal from the ECU to open at 70 deg, so I think what you are unplugging maconu is a switch or thermocouple not a sensor. The only sensor in the cooling system is the CTS and it’s in the engine case if I remember right? So you wouldn’t be “tricking” the ECU by plugging into another thermostat. I would think by doing so the thermostat that’s inline would never open and cause overheating. Maybe that’s why it’s popping more? It’s running lean and hot? The ECU can only compensate or correct the MAP based on all the sensor inputs within input/output capabilities or tolerance before going into limp, removing a sensor can really throw it off. Like I said, I can't remember where the CTS is but if it is in fact in the thermostat(doubt it) and you took it out as an input to the ECU that could explain your pops.

You’ll find lots of opinions on recovery or expansion tanks. I personally like them since if everything is working correctly they provide a chamber for air to expand to and reduce the need to constantly fill the radiator.