03 ec300 overheating

waycrazy

New member
Ok long story , my ec300 is overheating Bad! It has been a steady progression to this point. My jetting is 42/178 with a New carb w/ RB mods.I usually ride from 2000ft-6000ft at 60deg-90deg weather. My bike idles well and starts cold with no more then a couple kicks and warm with one. It always has burped up a little water and stopped once it get about a 1/8" above the fins. But on my last two rides things have changed.2 weeks ago after a steady but steep climb my bike overheated and half emptied my radiator. I waited tell it cooled and refilled the rad. I didnt have any problems after that. Now the ride I went on Sunday was a worse . Granted most of the riding was higher elevation and at 94 deg temps. And mostly hard work climbs (epic stuff). But my bike was constantly pukeing water . I gave it constant cool down times and at one point there was a long section of dirt road to the next trail . It even over heated on this. So I refilled and headed for the truck . Over heating and refilling all the way. I got home and pulled the impeller cover and the impeller was in good working order .
I am at a bit of a loss with this . If it was my jetting I would think the over heating would be evident day one. Not a slow progression to this point. I also want to add that it seams to be pumping the water out more then boiling it out. If that make sense . Pumps water out and gets hotter the lower the water level gets. I also noticed with the engine cold the water bubbles ,Faster or slower to engine speed.
I also have two other questions.
1. What happens when the water impeller seal lets go.
2. Can the head gasket leak enough to introduce pressure to the water system but not effect power and make white smoke?(wouldn't there be a fuel or some kind of odd smell to the water?)
Any help or suggestions would be appreciated . Even simple obvious stuff.
 
if the water pump seal goes the water will go in to the gear box and you can tell by the level going down and by the creamy colour of the oil through the view glass and you would of seen oil residue around the impeller.
if your head gasket o rings have gone i would believe it would loose power for a start and you would loose water again in to the chamber giving white smoke a bit like steam not the light blue 2 stroke oil. it would run like crap.

i would give the system a flush out, you could have a air lock some were.
check the rad cap is working try an swap it with a mates bike that's working
hope this helps you out not sure with the jetting side of things causing this tho
 
You dont always loose power with the orings going.. I lost mine and they went in a way where it was letting pressure in my coolant system to the point of bubbling in the rad and boiling over.. but had lots of power and no sign of extra smoke etc.. pulled the head and one oring was pushed out from the cylinder a bit..
A flush will not hurt also check your rad cap.. A combustion leak check kit from a parts store like napa will also help with minor pressure leaks,, it mounts to the rad and gets filled with a blue liquid and run the bike and if the color changes you have HC's present(unburnt fuel) and thus head gasket/orings. I use this kit all the time on small diesel and gas machines.. its harder to use on the bike due to the placement of the radiator but it pinpoints exhaust in coolant..
 
...I also want to add that it seams to be pumping the water out more then boiling it out. If that make sense . Pumps water out and gets hotter the lower the water level gets. I also noticed with the engine cold the water bubbles ,Faster or slower to engine speed.

I'd go straight to the head and replace the o-rings.
 
The water will move with revs as the impeller turns faster. If there are actual bubbles coming to the surface its more indicative of damaged o-rings. For the price I'd be looking at pulling the head and having a peek. Maybe drop the oil first and see how that looks too.
 
The water will move with revs as the impeller turns faster. If there are actual bubbles coming to the surface its more indicative of damaged o-rings. For the price I'd be looking at pulling the head and having a peek. Maybe drop the oil first and see how that looks too.
I had been thinking on pulling the head and sending it to Ron Black at the end of riding season anyways.... I guess it will happen a little earlier then I had thought.
 
Over a long period of time coolant can loose it's corrosion protection and the tubes in the rad will get coated with crap. The flow reduces so gradually that you really don't notice any change until it's bad. The coating on the tubes also reduces heat transfer from the rad. Usually the rads cool the motor enough when you're rolling along at a good speed, but as soon as you slow down the temperature rises dramatically. If all the mechanicals check out OK, then look to the rads as the problem.
 
I changed the cap from a 1.2 to 1.4 New coolant and changed oil . Also turned in the low idle air mix screw a little . Granted the air temps are a bit cooler today. Only about 88F but I did put it threw the ringer. Ran it up a dry creek bed with lots of big rolling rocks with good climbs. Also did a couple hill climbs and lugged the bike. I think I fixed the problem. In fact it didnt even put a drop on the ground in the 2hrs I rode. Since day one it would puke out a little water untell there was what the bike thought was a good level. But anyways I would like to thank each and everyone of you for your suggestions.
Thank you
 
I changed the cap from a 1.2 to 1.4 New coolant and changed oil . Also turned in the low idle air mix screw a little . Granted the air temps are a bit cooler today. Only about 88F but I did put it threw the ringer. Ran it up a dry creek bed with lots of big rolling rocks with good climbs. Also did a couple hill climbs and lugged the bike. I think I fixed the problem. In fact it didnt even put a drop on the ground in the 2hrs I rode. Since day one it would puke out a little water untell there was what the bike thought was a good level. But anyways I would like to thank each and everyone of you for your suggestions.
Thank you
Damn...I was was hopin' for some easy gettin' radiators:D: My old KTM had basically the exact same problem. Changed cap, burped the snot out of it...Good to go. Congrats, on an inexpensive repair.
 
Damn...I was was hopin' for some easy gettin' radiators:D: My old KTM had basically the exact same problem. Changed cap, burped the snot out of it...Good to go. Congrats, on an inexpensive repair.
No such luck for you bowhunter. Did you find the plastics you were looking for?
 
No such luck for you bowhunter. Did you find the plastics you were looking for?
I haven't even bothered to look. My priorities have run askew...HUNTING SEASON!!!! Busy at work...spare time spent beating the brush. I'm still seeking a big bear on the ground, for my longbow. Elk & Deer very soon. AHhhhhhh...I love this time of year. I'm shooting to be done with it by the end of Sept. I'll be off work nearly 3 weeks, starting Sept. 1st.
 
I ran two of those and an LTR impeller on my '07 with a 1.4 bar cap and it would not loose a drop in any conditions. They are on the '12 now, Checkpoint impeller going in, and going down to a 1.4 bar cap from a 1.8. I have to replace it anyway and shouldn't need a 1.8 if all else is well.
 
I hope I don't have to add one of those coolers. But if I do is that something that has to be mounted to something? What keeps them from banging against the radiator? I wish that Les still sold aftermarket GasGas parts. I have a few of his products on my bike and really liked the quality. So I suppose the checkpoint impeller will have to be what I use.A new impeller will have to be installed. The stk one in my bike is still in good shape but I dont want to be 50 miles in the back country and have it decide to fail. Since the stk impeller has such a bad reputation for failing I am sure that is a possibility.I learned a long time ago jeeping that a warranty will not get you out of the woods.So buy parts that will not fail.
 
The coolers are simple and light alluminum. Just cut a section of hose out and splice them in with a couple clamps. The tension of the hose holds them fine. I did not buy them for a GG originally, just had them left from another bike and said why not and installed them on my '07. They can't hurt.

The impeller can be OK for years, but some have failed in the past. Not widespread but it has happened. There used to be some pics of the failed ones around, maybe that was on the old Smackover site. If it was fine the factory would not have went to alloy at one time, obviously it was a concern.
 
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