Just got 450r and haveing MAJOR PROBLEMS!!! please help

[atvmaster0927]

ok, so i just got my 04 450r today.

I got home and took it riding down the street for maybe 15 minutes if that.

And it overheated.

So then i stopped and all i hear is my Coolent boiling! and some was dripping out of the overflow. Then i waited till it stoped and started it again and within 3 minutes it all starts over again. It also starts to backfire quite a bit.


On the 450r i have an built motor(i'm assuming 12:1 cp), tc shorty pipe, hot cam, porting, open lid, and some other stuff. *ALSO does not have a fan connected and has the key removed.*

Well, i'm thinking it might be the Water Pump or the radiater. i took off the cap to the coolant and added water to the top and let it run for a few minutes. It does not pump or move or anything. I think i'm going to buy a new water pump with the gaskets and stuff.

Might be jetting as well. (but i dont think so)...i'll check that later..

I'll also check to see if the two wires in the ignition are together...(red and black two)...


Does anyone know how i can fix it? Any help is greatly appriacated.
Thanks.

[450Rchaser]

Does your fan work and is your radiator clogged up with mud?

[atvmaster0927]

It doesn't have a fan. I dont think it's clogged, there's nothing sticking on it.

[REPOMAN]

OK I AM NOT THE SMARTEST GUY IN THE WORLD BUT I WOULD ASSUME THAT A BUILT MOTOR WITH NO FAN IS A REALLY REALLY BAD IDEA. A FAN IS THERE TO "COOL" AND WITHOUT ONE IT MIGHT NOT "COOL" AS WELL AS IF IT HAD ONE.

[pro-rider46]

sounds like a bad thermostat, i would replace that before anything else, the thermostat will bypass coolant so it doesnt go through the radiator, it sounds like it just keeps by passing. or the thermostat is stuck upon.

[BlackTrx440ex]

i also have a 450r with a built motor and it overheated but my problem was i had 50/50 coolant in it. use the good coolant, i also dont have a fan that works...

[atvmaster0927]

What do you mean 50/50 coolent? I'm going to use engine ice.

And what is the thermostat? where is it? And like what do you mean?

Well i filled it up to the top with water and started it and let it sit for a few minutes and it just sat there, didnt move or anything. Should i replace the water pump?


Any other help is apprieacted.!

[REPOMAN]

put a fan on it

[j_cyrus3]

Originally posted by REPOMAN
put a fan on it

Ya. They came with a fan for a reason.

[Scro]

The fan is not the problem. I ran a whole XC season without a fan and only overheated once (because of mud). I say its a combination of bad thermostat, and your jetting being off (since you said it was backfiring).

I'm fairly possitive the honda thermostats stock are fail safe ones. So even if it did go bad, it shouldn't have overheated. By 50/50 mix he means he had 50% water and 50% antifreeze. You said when you boiled over you just added water, you diluted what you have even more so. I'd put an inline temperature guage and see how bad it's getting.

[atvmaster0927]

Originally posted by Prodigal
I'm fairly possitive the honda thermostats stock are fail safe ones. So even if it did go bad, it shouldn't have overheated. By 50/50 mix he means he had 50% water and 50% antifreeze. You said when you boiled over you just added water, you diluted what you have even more so. I'd put an inline temperature guage and see how bad it's getting.


i added it to see if the coolant was mixing, like going through the engine. But it NOT move so it must be a Water pump? right?

I'm going to check the jetting tomorrow. What should my jetting be around? mods are listed in first post. I live about 280 - 500 ft above sea-level.

What is the theremostat exactly? should i remove it? or just get a new one? where is it and what does it look like?

I will get a fan from honda.

Also i was using the clutch alot because i went on a coupe trails for about 3 -5 minutes total and was stalling quite a few times. it was also tight trails....could that be it?

So then what should i be looking for and doing to fix my problem?

The thermostat is effectivley just a valve that restricts the flow of coolant. The inside is filled with wax and a spring. When the engine gets up to temp, the wax melts, expands, and the spring opens the valve so coolant can get to the engine. They go bad a lot on cars. I'm not sure about atv's but I know on cars you can get different temperature ones, my car thermo is 20 degrees colder than stock. Colder they run the more hp usually. But like I said, MOST thermostats fail in the open posistion so they don't cause you to overheat. So unless honda went cheap on us it shouldn't be that. I know some of the people on here have posted their running temps though and they were literally right on the edge of what the max you can run. So the jetting alone might actually be enough to throw you off.

[atvmaster0927]

Thanks for the write up!

But i was reading that it could also mean i have a blown head gasket? and if i continue to ride, coolant will enter the coombustion chamber. How can i check my head gasket?

Also where is the theremostat exactly? Can you post of picture of what i need to do? Thanks so much.

Also what jets should i be running with all of my mods?

The thermostat is under the housing where the upper hose connects to the engine.

If it was my quad I would take the thermostat out. I haven't run one in my quad for years. I would also get a fan assembly off of ebay or some place like that and install it to run all the time. Mine is wired to come on as soon as I start my quad.

Jetting I would start with a 185 main, a # 50 pilot and move the needle up on notch.

If you had a blown head gasket, which I doubt unless it was really overheated badly, the coolant and oil would have mixed by now and the oil would look like a chocolate milk shake.

I would bet money that the water pump is good. the coolant probably isn't moving because the thermostat is stuck shut. Like stated above the thermostat also control the speed of the flow of coolant so it has time to cool off while passing through the radiator. Unlike a car the 450R has a hole the size of a pencil the the coolant goes though approaching the thermostat. the restiction of that small hole slows it down enough to cool down, so no thermostat needed unless you ride in very cold weather. I don't have that problem in South Florida.

[kraemer]

if your running through trails anything lower then 3rd gear you need a fan... you will not see coolant moving while the engine is running, it should stay the same level... also your jetting plays a big factor in this, but if your going slowing enough to stall you are not going fast enough to cool the engine. you can run w/o a fan but you need to always have air moving across the radiator

lower t-stats does not always give you more hp... if you go too low for a given engine you will cold shock the block when you put the engine under heavy load...

put a fan on it and re jet... if you want to check if you water pump works, drain you radiator and flush system. fill your system with straight water. remove your upper radiator hose from the radiator and start the bike. if coolant is flowing from the upper hose, from the water pump as you add water to the radiator your pump is working. then drain your system, since its straight water you can do it on the ground... now refill your system with a 50/50 mix, or engine ice.

to check your t stat you need a infared temp gun to do it easy...

In my opinion you need a fan and to rejet


EDIT: if you blew a head gasket, you would have other complications by now. check you oil level, if it is the same you did not blow a head gasket, if you blow a gasket on a water cooled bike, you will see a overpressurized cooling system and coolant through the exhaust.

your jetting has many variables... read up on it, USE THE SEARCH . your altitude and weather has alot to do with it...

[atvmaster0927]

Thanks everyone for all this good info. I just have another question. So is it ok the completely remove the thermostat and never use it? Does it just slide out or something?

Also should i just run 100% of engine ice?


I just really dont wanna blow the motor.


Also i think the guy before me had put a new cdi in, could that be the problem? i also have a blingstarr iron cross, could the be blocking to much airflow?

[atvmaster0927]

bump


Thanks everyone for all this good info. I just have another question. So is it ok the completely remove the thermostat and never use it? Does it just slide out or something?

Also should i just run 100% of engine ice?


I just really dont wanna blow the motor.


Also i think the guy before me had put a new cdi in, could that be the problem? i also have a blingstarr iron cross, could the be blocking to much airflow?

[pro-rider46]

if its cold, you will need a thermostat, they are about 25 at the dealer. since your in new york and they are only 25 bucks i would run one

[atvmaster0927]

Originally posted by pro-rider46
if its cold, you will need a thermostat, they are about 25 at the dealer. since your in new york and they are only 25 bucks i would run one

well its about 75 - 100 degress in the summer here, so i'd be fine for now.

Also i think the guy before me had put a new cdi in, could that be the problem?

i also have a blingstarr iron cross, could the be blocking to much airflow?

[400exrapes]

Atvmaster and I will be looking at the jetting today, and we'll also take a look at the thermostat. He'll definatley buy a fan and some engine ice. He forgot to mention that he is burning a little oil upon startup. We're going to check the plug, and jetting , and probably change the oil today and if the problem consists we'll look at the thermostat.

[400exrapes]

Nevermind, atvmaster pulled the thermostat, and it was closed. The quad runs fine now, but I'm assuming still backfires and smokes....

You do not mix water with Engine Ice, you run 100% Engine Ice.

[atvmaster0927]

well, when i took my thermosat off, it was stuck and would not open..so I took off the thermostat completely and went riding for a couple of hours and it ran almost perfect, it was still backfireing, so I checked the jetting and it was wayyy to lean, it only had a 175 in it, so 400exrapes is going to give me a 185. Should be perfect after that.

Thanks everyone, I appriate it.

[d3ktrix]

Originally posted by atvmaster0927
well, when i took my thermosat off, it was stuck and would not open..so I took off the thermostat completely and went riding for a couple of hours and it ran almost perfect, it was still backfireing, so I checked the jetting and it was wayyy to lean, it only had a 175 in it, so 400exrapes is going to give me a 185. Should be perfect after that.

Thanks everyone, I appriate it.

The thermostat is supposed to be closed when its cold.
Boil some water on the stove and drop the thermostat in it, should open right up if its good.
If it doesn't, what was ur problem I guess :P

A lot of people run w/o thermostats, but IMO its better to run one. Cooler isn't always better, engine will run the best with the least wear at the correct temp.
Like said above tho, more of a problem in colder temps.

[atvmaster0927]

Originally posted by d3ktrix
The thermostat is supposed to be closed when its cold.
Boil some water on the stove and drop the thermostat in it, should open right up if its good.
If it doesn't, what was ur problem I guess :P

A lot of people run w/o thermostats, but IMO its better to run one. Cooler isn't always better, engine will run the best with the least wear at the correct temp.
Like said above tho, more of a problem in colder temps.


Yeah it was my problem. It was stuck and did not open. Thats why my coolant kept boiling. In winter i'll buy a new one. Ran fine though today:devil: