140 GPX oil leak

[Howorks]

After a few rides I noticed that some oil on the skid plate under the engine. I torqued the head bolts and made sure the gasket is sealing tight. Seems to be coming from that square hole but not sure.

Any having the same problem?

[Howorks]

Nope...

[mattv]

stupid question - but is the oil drain plug properly torqued?

perhaps loosen the top bolts and check to make sure that everything looks fine on top and re-torque the bolts. Clean the motor up really well and run it for a while, you should be able to figure out where the oil is coming from if it's still leaking.

[Howorks]

stupid question - but is the oil drain plug properly torqued?

perhaps loosen the top bolts and check to make sure that everything looks fine on top and re-torque the bolts. Clean the motor up really well and run it for a while, you should be able to figure out where the oil is coming from if it's still leaking.

Its not coming from the oil drain. It only leaks under hard acceleration. It will not leak while idling.

[mattv]

my 124se did that exact same thing when I first got it.

I properly torqued the top head bolts and it stopped. I'd bet one of your gaskets is out of place or perhaps you missed an o-ring on the re-install job?

[Howorks]

Head bolts are tight. I went to 14ft/lbs. Not sure what is recommended on a GPX?

I'm sure I got all the o-rings. I think its that metal head gasket that sucks...

[Twitchy]

Those metal head gaskets are freakin garbage. I think I got a vacuum leak. I haven't ever been able to get my bike to run right. Sucks

[Howorks]

Those metal head gaskets are freakin garbage. I think I got a vacuum leak. I haven't ever been able to get my bike to run right. Sucks

any better options?

[jhedges]

Is it leaking between the head and cylinder? on the left side near the shifter?

[Howorks]

Is it leaking between the head and cylinder? on the left side near the shifter?

Yes exactly

[jhedges]

We had a o-ring with a metal washer in the inside of that o-ring that goes in the oil return hole that sits on the top of the cylinder. Take out that metal washer. The metal washer is .60, and the inset of where this metal washer and o-ring sit is .40. So the metal washer was sticking out .20 and not allowing the head to seat properly and seal. Once we did this our oil leak went away. Ours was leaking bad too. Also, we had no compression with this oil leak too. Once we removed the metal washer our compression was then normal. We fought and fought this problem. After taking the head off for the 3rd time we decided to remove the metal washer after measuring it and discovering the .20mm gap. Hope this helps.

[Outlaw Powersports]

^^^^jhedges you hit it right on the head (no pun intended). We just received this update from TB on the 140 kit.

"INSTALLATION NOTE: Don't use the original o-rings between the head and cylinder (not needed) but do use the large o-ring at the bottom of the cylinder between the cylinder and the engine case at the oil return.

If you leave the original o-rings in between the head and cylinder, there is a good chance you will get an oil leak."

[Howorks]

We had a o-ring with a metal washer in the inside of that o-ring that goes in the oil return hole that sits on the top of the cylinder. Take out that metal washer. The metal washer is .60, and the inset of where this metal washer and o-ring sit is .40. So the metal washer was sticking out .20 and not allowing the head to seat properly and seal. Once we did this our oil leak went away. Ours was leaking bad too. Also, we had no compression with this oil leak too. Once we removed the metal washer our compression was then normal. We fought and fought this problem. After taking the head off for the 3rd time we decided to remove the metal washer after measuring it and discovering the .20mm gap. Hope this helps.

I removed the metal part but left the rubber o-ring. And now that I see the update from TB.. it makes sense that I have an oil leak since the rubber one is not needed. I will remove this week and report back...

[jhedges]

you can leave the rubber washer. We did, and don't have any problems.

[Howorks]

^^^^jhedges you hit it right on the head (no pun intended). We just received this update from TB on the 140 kit.

"INSTALLATION NOTE: Don't use the original o-rings between the head and cylinder (not needed) but do use the large o-ring at the bottom of the cylinder between the cylinder and the engine case at the oil return.

If you leave the original o-rings in between the head and cylinder, there is a good chance you will get an oil leak."

Well since I have an oil leak and I left the o-ring between the head and cylinder in place... the information above makes sense. I need to remove that oring and see if the leak continues.

[Howorks]

Damn it... I removed the o-ring and it still leaks. &%$#@!??

[jhedges]

Damn it... I removed the o-ring and it still leaks. &%$#@!??

Try just removing the metal washer and leave the rubber o-ring and see if that helps.

[Twitchy]

i had to get a good o-ring from the auto parts store. Just get rid of the metal o-ring without an o-ring it will leak.

[Kurlon]

It all depends on the thickness of the gasket. Too thin and the rubber oring can cause a leak on it's own. I don't have a TB gasket to measure, so I can't advise weather or not to run an o-ring.