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2006 RMZ450 Overheating??

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I'm new to Fourstrokes and need to know if anyone else has troubles with their RMZ450 Overheating? I never let it idle so that isn't the problem but the track we have is deep sand and I always had trouble with heat on my 2-strokes. But with this, it kind of scares me since I first didn't really worry having a bit of antifreeze come out of the overflow when I stopped. But I think it does it while running as well because it ran low on antifreeze a few weeks back. Now from this, I seem to now have oil leaking from the cam cover. I checked the cams on the weekend and the clearance is a about .05mm too little to what the manual indicates. Can this cause this? Also, the oil leaking from the cams is getting worse. Does anyone have ideas what I should be checking. Also when checking the cams, there seems to be a significant amount of oil on the cams..

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last Sunday at the races down here there was an 2006 rmz450 overheating also. even when they shut it off antifreeze was pouring out and covered the whole bed of the truck with it. i think there is a problem with the bike

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We have had the same problem with loosing coolant on our 06 all year. I tried a lot of things including checking the head gasket several times. Finally found that the top surface of the cylinder was the problem. It was warped slightly, almost undetectable and had a small low spot by one of the water jackets. Under extreme conditions it would always loose a small amount of coolant and got to the point of boiling over badly when rode hard. I resurfaced the sealing surface by sanding on a piece of sheet glass and have had no more trouble. We live in Oklahoma and it has been 100 degrees plus and have not added any coolant since repaired.

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Thanks alot for your help. Is there anything I need to worry about with taking the top end apart other than making sure the cams are right? Anything like little pieces that will fall off (and maybe make it's way into the motor) when I pull the cylinder? I found when I pulled off the cams last weekend, I dropped one of the shims. I looked for quite some time to find it but for a while there, I thought it dropped in the motor. I ended up finding it but four a while, there was thought I was going to have to pull the whole thing apart to find this.

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It is hard to tell you all the things to do on a 4-stroke top end without knowing your mecahanical experience. Anything that falls in the engine will most likely fall into the cam chain hole and you can just pull the left side cover to find it. There are plenty of things to watch for such as not over-tightening the upper cam holders just to mention a few. If you are not sure what to do find a good mechanic to help so you do not cause yourself more trouble. It took me quite some time to find the problem and I have been working on bikes since the early 70's

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Engine ice and some of the other coolants are slightly better than what some people may put back in their radiators but if you actually have a mechanical problem nothing will stop the coolant from blowing past the cap and/or the radiator getting low. A 1.6 rad cap will help if all else is ok and you are just pushing the bike really hard. If you mix a quality antifreeze with distilled water at 60% coolant to water it will handle just about anything.

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Buy some Engine Ice and your bike won't over heat and will run better with more power.

If he has a mechanical problem with his bike, putting a different kind of coolant isn't going to do anything, it will still leak, and he will still have that problem. I don't know about you but I would want the bike in perfect running order, he shouldn't be losing any coolant, other than the overflow, and idling overheating, etc...

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I'm new to Fourstrokes and need to know if anyone else has troubles with their RMZ450 Overheating? I never let it idle so that isn't the problem but the track we have is deep sand and I always had trouble with heat on my 2-strokes. But with this, it kind of scares me since I first didn't really worry having a bit of antifreeze come out of the overflow when I stopped. But I think it does it while running as well because it ran low on antifreeze a few weeks back. Now from this, I seem to now have oil leaking from the cam cover. I checked the cams on the weekend and the clearance is a about .05mm too little to what the manual indicates. Can this cause this? Also, the oil leaking from the cams is getting worse. Does anyone have ideas what I should be checking. Also when checking the cams, there seems to be a significant amount of oil on the cams..

did you ever figure out the cause?

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It is hard to tell you all the things to do on a 4-stroke top end without knowing your mecahanical experience. Anything that falls in the engine will most likely fall into the cam chain hole and you can just pull the left side cover to find it. There are plenty of things to watch for such as not over-tightening the upper cam holders just to mention a few. If you are not sure what to do find a good mechanic to help so you do not cause yourself more trouble. It took me quite some time to find the problem and I have been working on bikes since the early 70's

what grit did you use?

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My 07 did the same thing. Upon disassembly, I found a trace of antifreeze leaking from the coolant port to the cylinder so I trued up the bottom of the cylinder head by .005" and went with a stock gasket . That got it better but not fully repaired so I tried a new radiator cap. That was better but ultimately found the cylinder plating was flaking off on the exhaust side. A known issue with Suzuki cylinders in years 05-07. The issue was probably exaggerated when the motor would get hot and disfigure the head and start to leak coolant into the cylinder.

After the plating flaked off...I went with a complete rebulid. Crank, valves, valve springs, valve seals, cylinder! , piston and rings.

Costly repair but avoided the granade potential later on...

Just my 2 cents.

Edited by suzukidad
mispelling

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My 07 did the same thing. Upon disassembly, I found a trace of antifreeze leaking from the coolant port to the cylinder so I trued up the bottom of the cylinder head by .005" and went with a stock gasket . That got it better but not fully repaired so I tried a new radiator cap. That was better but ultimately found the cylinder plating was flaking off on the exhaust side. A known issue with Suzuki cylinders in years 05-07. The issue was probably exaggerated when the motor would get hot and disfigure the head and start to leak coolant into the cylinder.

After the plating flaked off...I went with a complete rebulid. Crank, valves, valve springs, valve seals, cylinder! , piston and rings.

Costly repair but avoided the granade potential later on...

Just my 2 cents.

Mine is not a issue of burning the coolant, it spits out the over flow. Thinking head gasket is allowing exhaust or compression in to the coolant system.

I pulled the head and lapped the head with a 600 grit, did seem to be uneven.

New head gasket, and ran the bike today. Is better for sure. I think a alot of heat comes from the pipe being so close to the rad as well. 300c+ only a inch from the right rad. Going to look at a possible heat shield between the pipe and rad.

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Mine is not a issue of burning the coolant, it spits out the over flow. Thinking head gasket is allowing exhaust or compression in to the coolant system.

I pulled the head and lapped the head with a 600 grit, did seem to be uneven.

New head gasket, and ran the bike today. Is better for sure. I think a alot of heat comes from the pipe being so close to the rad as well. 300c+ only a inch from the right rad. Going to look at a possible heat shield between the pipe and rad.

My symptoms were exactly the same. Coolant coming out the overflow...from overheating...or compression getting into radiator...

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I've wrapped my header with exhaust heat shield tape. I assumed it would pick up all dirt possible. But quite the opposite: it stays entirely clean. It also runs cooler as the heat does not reach the right radiator. Cooler bikes seem to have more HP :thumbsup:

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the coolant, it spits out the over flow.

Check your carb. I almost guarantee that the pilot jet is partly to completely blocked, and needs to be replaced (happens frequently with the crappy ethanol gas these days). If you richen up your jetting, your bike will run cooler. I run

42 PJ, needle #3 clip from top, 170 MJ, fuel screw 2 turns out.

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