Hi All, the problem i had the other day with the temp light turning on could be traced back to lack of coolant in the radiator and my mechanic told me this is caused by air in the radiator. After draining the coolant and putting in new one making sure no air in the radiator, i rode the bike again for about 100 miles and after checking the radiator i seem to be still losing coolant and the engine oil level has also dropped which also happened previously.

Although the temp light did not turn on this time but i am not sure why i am losing engine oil and coolant. There is no leak at all. Hope someone can help me out here, getting this bike and modifying the big bore is turning out to be a nightmare.

 

It's not unusual for the engine to use a little oil on a fresh rebuild of the top end until the rings are fully seated. That's why you shouldn't use full synthetic until you have racked up some miles-full syn slows the 'bedding' process. Just keep an eye on it and top it off.
The coolant problem may be caused by not fully 'burping' the system after the engine gets up to temp and allows the t-stat to open. If you top off the rads when the engine is reassembled and don't check the level in the rad after a heat cycle it will appear that you are losing coolant when all that is wrong was not getting all of the air out in the first place. Having said that, if the tech did the proper heat cycle check and there are no visible external signs of leakage then the only other way the engine can lose coolant is a leaking head gasket. Simple test for that is to leave the cap off of a full rad and start the engine-if bubbles start to appear in the rad neck then the gasket isn't sealing and it's allowing combustion pressure into the water jacket.
Good luck...

 

Thanks a lot for your explanation, i feel much better now. I will do the test tomorrow to check if there is a leak but if lets say there is a leak and i would have to remove the head again, do i need new gaskets when i reinstall the head? im using a Bill Blue 331 Kit, are the after market gaskets i can buy for this purpose? i emailed Bill for it but he usually takes a while to reply but if i can find an alternative that would be great.

 

Sorry to hear of your troubles. I had nightmares about such things happening to me on my build. Luckily, so far I have experienced no problems with my project Anyway, yea, pretty much what Gabuto said... I was going to actually say before that you might just have low coolant. If you have to top off the coolant overflow tank more than about a couple times, then it's either your head gasket or a slow leak that you don't notice (like through the gasket at the water pump, for example). I'd suggest looking very closely for any signs of leakage from any of the gaskets, seals, radiator, or hoses. It may not be apparent when the engine is off/cold, but become apparent when it is hot. Also check for any white "smoke" coming from the exhaust pipe (can mean coolant leaking into combustion chamber and getting burned). Oh and I think you will need Bill's gaskets, unless you could get them directly from the manufacturer, which probably wouldn't be any easier or quicker. If you have to pull the head for that reason, you'd definitely want to replace the gasket. They don't cost much so there'd be no reason not to do so. If you have your mechanic get into the head, you might suggest they verify head bolt torque before actually removing the head. It's a possibility they forgot to torque one or two of the bolts down when they installed it...

 

Thanks for your feedback. i did the radiator test and there were bubbles appearing at the neck of the radiator opening, could there still be air in the radiator and it has not "burp" finish or it is a confirmed head gasket leak?

having said that, there is still no smoke at the exhaust, if there is a leak shouldnt there be smoke at the exhaust? Bill asked me the same question. but i am losing about 100ml of engine oil which i believe is not normal even with a Big Bore break in, am i right?

 

The liquids have to be going somewhere.
Is the engine leaking oil, does it leave a stain? 100ml of oil being burnt would probably put out a very visible smoke tail that hangs in the air.
Same with radiator water, if it is getting into the cylinder, it would put out a visible white smoke that desipates rapidly.
If the water is getting in the oil, it will be milky.
If you have none of these symtoms, I would wager that you did not get the systems filled properly. Just keep topping them off, eventually all the air will be out of the radiator system & the oil loss will stop.

 

There is no stain at all, no signs of leaking, no smoke and no milky looking oil at the oil window level screen. just losing radiator fluids and engine oil. the problem with water entering the engine actually happened the first time the gasket was installed on the head when installing the big bore kit, this was done by the tech. lucky i ordered an extra gasket, he re-installed the new gasket and there were no more water entering the engine.

so i guess this must be "air" in the radiator problem? but can air in the radiator also cause the bike to lose engine oil as well? i will continue to top up radiator fluid and see how it goes.

 

One more thing i noticed since i had the problem with the radiator fluid level dropping when i open the radiator cap, the problem is the radiator fluid reservoir at the bike shows full all the time even though the level of fluid in the radiator have dropped, can anyone let me know what could cause this?

 

The reservoir is only an overflow, not part of the system. To check the level, one needs to remove the cap.
If you remove all the air out of the connector hose from the radiator to the overflow, this may connect these systems, more like what is found on an auto. But I don't believe that this is necessary or needed since the klx really doesn't run super hot or have a huge volume of fluid that would require fluid move back and forth.

 

Another possibility is if the cooling system is over-pressurizing because of a gasket failure, then the 'lost' coolant will be in the reservoir. Check the level in the catch tank and the rad after you are sure that all of the air is purged from the rad and run the bike. If the catch tank level has increased then it's likely that your coolant is being forced past the cap and ends up in the catch tank.