KDX50 JR50 Transmission oil change

[StromClod]

Hi folks - Got my kid a used 05 KDX50 about two weeks ago but it didn't come with an owners manual. Seller said he'd mail me one but hasn't come through just yet.

Has anyone who has changed the tranny oil tell me how to tell the correct fill level and what type/weight oil to use?

I see an indent on the right side of the engine case that's kind of elongated. Is that some sort of indicator? Like "try to keep the oil between here and here" kind of deal?

Been lurking here since we got the bike and have already learned a ton, but haven't seen anything on this yet. Many thanks in advance! :)

 

[Jasle]

don't know the amount off the top of my head but I'd use Maxima MTL 75wt oil for that trans. That stuff works well with auto transmissions. I'm thinking the amount is stamped on the right cover?

 

[StromClod]

Thanks for the reply. I "think" I figured out the level but not 100% sure. There is a smaller hex/phillips bolt type deal on the side of the case with what looks to be a crush washer on it. I'm guessing that it's a fill till oil runs out type of setup.

Appreciate the feedback on the oil but I'm not sure the tranny is auto. I know the clutch is an auto, centrifugal setup. It's been about 25 years since I've owned a two stroke bike, so someone please correct me if my "sometimers" is kicking in, but I thought I remember that the crankcase/tranny oil lubed the crank as well and the 2stroke fuel mix lubed the top end. If I'm right, I'd be leary of that heavy a weight oil in the crankcase. I wouldn't bet a burger and frys on it though! :laugh:

Anyone got an owners manual know what the recommended oil type and wt is? Thx again! :)

 

[jamesh75]

I am not sure about the KDX50, but my son's 05 PW50 manual says it takes 300ml of Yamalube 10w30 or any automobile 10w30 oil in the tranny. I would say the weight would probably be the same for the KDX, but the amount may be different. It should be stamped on the motor near the fill plug.

 

[StromClod]

Thanks for the reply. That seems to jive with my memory from my two stroke dirtbike days. I thought I remember using like a 10w30 but wasn't sure, been a bit too long ago. Think I need to order an owner's manual. The previous owner seems to have forgotten about me. Thanks again! :)

 

[StromClod]

Ok - Got a hold of a service manual for an 03 KDX/JR 50. Mine's an 05 but I doubt there is any meaningful difference in this case.

It takes half a litre of 10w40, says 450ml for a change. Just says to use a "quality engine oil." The drain plug is obvious on the bottom of the motor, as is the fill cap on the right side of the motor. To get the proper level you will find a hex bolt with a crush washer on the right side engine case, not quite 1/2 way up. Mine can also take a phillips screwdriver. I was right in my initial guess - get the bike upright and fill till it starts to come out of that sidecase hole. Manual says to change every 6 months.

Since no one else seemed to know for sure, I thought I'd just post the info in case it comes up again in the future. Thanks for the previous input! :)

 

[Jasle]

also the oil you put in the trans DOES NOT lube the crank. Your premix does that. the crank/crank bearings/rod bearings and piston are lubed and sealed apart from the trans. there are other quality premix/injector oils that are less expensive than yamalube.

BTW 75wt gear oil is pretty much the same viscosity as 10W30. 85W90 is close to 10W40. Motor oil and Gear oil use different scales but are close to the same wieghts...

 

[StromClod]

Thanks Jasle. Like I said, it's been a long while. The light came on when I changed the oil and I was looking closely at the engine. Just the distance of the tranny from the bottom of the cylinder, and the level of oil in the crankcase had me thinking that there is no way this oil is bathing the crank bearings, etc.

I'm going stick with what's in the book oil-wise since I already have it handy. Appreciate the info though, may come in handy in the future. :)