Coolant leak, top of Engine

[rosco]

2006 Apex GT. It ran great all last season with no issues relating to coolant levels. I just finished doing some preseason mtce including exhaust doughnuts. I noticed while workin on the doughnuts that I had some coolant poolling in the area where the solid tubing goes into the top of the valve cover on theright hand side. I am wondering if anyone has had a similar situation. I am thinking it could possibly be related to the O ring item 3 in the schematic. If it is I hope that I can remove the tube from the valve cover and replace it without introducing any coolant to the oil system. This looks like it could be possible because the valve cover gasket has a sealing surface that surounds the tube aswell as a seperate section that surrounds the spark plug

Any input is appreciated. I am goig to try and attach some pictures of the are as well as the parts schematic.

 

[Iceman57]

When you worked on your sled did you take the antifreeze overflow bottle off or disconnect any tubes? If so the antifreeze in your pix could be from that.

 

[Yamahammer485]

When you worked on your sled did you take the antifreeze overflow bottle off or disconnect any tubes? If so the antifreeze in your pix could be from that.

Ditto

Id have to say its just from a leak from something to do with the resevoirs and tubes. Its super easy to drop some coolant down there.

Also, when was the last time the sled was ran? If the motor got hot, there would be no coolant on the head, just a residue and you would smell it (smells sweet) This will give you a time that the leak could ahve occured.

 

[turbine man]

coolent

I had the same problem i was able to tighten the allen screw to stop the leak on the oring Jeff

 

[rosco]

I did have the collant resevior and overflo container diss mounted but I dried the area out after installation and have ran it about 4 times after everything was reinstalled and the coolant has re appeared. I have let the Engine reach operating temp each time in hopes that it would drie out the area but it did not and the coolant has re appeared. I believe this is a genuine confirfirmed leak.

Turbine man, when you say you had this happen and tightened the allen head bolt. Did you see coolant similar to what I am seeing? I will check and see if minecan be tightened. On a side note from your user name are you an Aircraft Engineer?

 

[turbine man]

coolent

rosco I have a turbo vector, my riding buddies allways ask if i am bring out turbine thats what they call my sled. i am a master marine mech. by trade, the antifreeze would aiiways puddle around the bottom of the tube, tighting my allenbolt took care of my leak, good luck Jeff

 

[lakercr]

Every RX/Apex engine that I've torn down have had mineral deposits on the coolant manifold where the o-rings seat. Best advice would be to drain your coolant; remove manifold; clean o-ring seat area; apply some vaseline to seat area and re-assemble.

Your leak would be on the 'extreme' end of what I've seen, but it is not at all unusual.

 

[rosco]

Thanks to all that replied. I will let you know what I find.

Lake rcr, I assume that after draining the coolant I will be able to just remove the allen bolt and lift the tube out without worry of contaminating the oils syst.

 

[lakercr]

Thanks to all that replied. I will let you know what I find.

Lake rcr, I assume that after draining the coolant I will be able to just remove the allen bolt and lift the tube out without worry of contaminating the oils syst.

Correct.

Do you want me to post some pics of the manifold, head, etc. on the bench? I have a few motors apart right now...

 

[rosco]

Lakercr thanks for the offer byt it looks pretty straight forward. If I have any questions once I get into it I will get a hold of you. Thanks again

 

[RX1Jim]

From what I am seeing, the steel tubes used in the yamaha 4 stroke sleds corrode quite badly on the inside despite having antifreeze with a corrosion inhibitor in it. I suspect we will be seeing many of the 03 and 04 sleds having problems with these pipes leaking in the near future. I beleive the mineral deposits seen at the connection of the plated steel pipes to the aluminum is a actually deposits from the corosion. i believe the corrosion is caused by the connection of the two dissimilar metals. Yamaha would have been better off making these pipes out of aluminum or stainless steel.

 

[apexrtx006]

got a 06 apex rtx with yhe same problem tightened the allen bolt never helped but havent had to add any coolant its like 1/4 inch down when hot after 1 year like that

 

[rxrider]

The tube itself may have broken off close to where the ear with the allen bost attaches to the engine. This happened on my friends '06 Attak, he tried to tighten the allen to no avail, it still leaked even without running the engine. When we rugged the pipe back and forth we found it had a crack all the way around, even with the crack it bearely leaks, but it looks just as in the pics.

 

[rosco]

It's all back together and dry. Here are two pictures showing what it looked like once disassembled. The O ring looked in good shape but I replaced it anyway. The pipe is an alluminum pipe and just had the usual goop on it. There was a small ring of hardened debris on the pipe that reqiured some emery cloth to remove. The sealing face in the head was pretty clean over all but also had a small area of hardened debris.
Thanks to all for your input. It is back in service and the area is dry.