Bike doesnt like the gearbox oil

[pyromaniac]

I changed the gearbox oil(first time since bought) to a 10w40 car oil. A friend was recomended to run cheap car oil and change often in his 02cr125. However i have a 00rm125 and it doesnt seem to like it. Anyone know whats recomended by the manual? What would you recomend?

The bad behaviour is that it gets into "neutral" with a ratteling sound for a few secs somethimes when i change gear. Doesnt sound nice at all.

 

[cr25096er]

your clutch is toasted. take the clutch cover off n inspect the basket, if its grooved then u need a new basket + the metal fiber and springs. if the basket looks good then just replace the springs and plates.

 

[pyromaniac]

I think and hope thats not the case. The bike have around 10hours on it. The neutral thing came right after i changed oil, no problem at all before. Also i have had the same thing on my last bike. Not at all this much but it happend somethimes after a time of hard riding on the MX track.

I will take a look how it looks but i expect to see a brand new looking clutch.

Still have the question. What oil is recommended?

 

[KX125pinball]

do not use car oil. It contains anti-wear additives for the piston in a four-stroke. This shortens the life of the clutch in your 2-stroke. Use a good quality 2 stroke gearox oil

 

[darringer]

I had a 99 RM125 and it absolutely loved the Honda Racing gear oil. (The one that comes in the red bottle). Bike shifted easily and positively. I used to change it every other ride. Had great results.

 

[Vic]

Originally posted by KX125pinball
do not use car oil. It contains anti-wear additives for the piston in a four-stroke.

I think you're refering to "friction modifiers", which are not present in 10w40 oils.

 

[Danman]

The "friction modifiers" are commonly found in synthetic oils and should not be found in any 10w40 oil that is a standard dino oil. Synthetic oils do come in 10w40 so read the labels.

 

[pyromaniac]

I checked the clutch and i could not find anything wrong. I then filled it up with a 10w30 caroil and took if for a ride. Only one time the neutral thing happend and it was when i was going real slow.

 

[marcusgunby]

I would guess a slightly thicker oil would work better in the RM-try some 15w/40 next time-you need to try all different types to see what you bike likes.

 

[DEANSFASTWAY]

Is it really cold out ? Its got to be pretty cold in Sweden , YA ? You folks have the most beautiful blond women in the world .On Crs when it gets real cold out and with thicker oil the kickstarters would srip or not catch if you kicked real rapidlywith thick oil in cold weather. The spring in the ratchet mechanism didnt posses enough energy to force the gears together and mesh . Maybe thats kind of whats happening in your RM . Most manuals have a list of viscosities to use in the inherent temperture range . Four stroke manuals espescially . If you keep riding it and hear stripping you coul be causing the gear dogs to strip or round off or could be influencing a shift fork to bend .Maybe in SWeden you need like a 5/30 oil . Isnt it dark out ? How can you see to ride ? CHEERS DEAN

 

[marcusgunby]

damm didnt notice the sweden location-ignore my last comment.Too thick a oil for euro winters.

 

[pyromaniac]

So i should not try 15w then? Its not very cold now, its around zero(celsious). Should i try 5w? How does the different thickness affects the gearbox/clutch? The onlything i know about gearoil is that the first figure is now thin the oil is when cold and the last how thick when hot. Could you tell me more.

Yeah the gearbox can be pretty sticky when its cold like -25, hard to kick and you have to have it running in neutral for a while before you can put a gear in or it will be just like you didnt pull the clutch. However this is the first winter i have had my bike in a warm storage so i havent felt that at all.

Guiss i will buy a normal bike gearbox oil but i would like to be able to run car oil cause its so much cheaper. Maybe i dont have to change oil so often in this bike as my last.

 

[marcusgunby]

My honda or KTM manual(cant remember which) has a guide on the oil grade depending on outside temps-see if your manual has one.I would think 0oC needs a pretty thin oil.ATF F maybe a good choice-its about a 7.5wt.

 

[A-RustyDemon]

pyro' the manual recommends 10W40.. But then again they are thinking that most people pack their bike away long before the temp drops past fourty. And even though your keep your bike in a heated area. The case temp will drop some while riding.. all that cold air rushing by. Anyway I'm with marcusgunby.. go with the ATF type F fluid. It's about the same consistency as BelRay's Gear saver.. come to think of it same color.

 

[pyromaniac]

I think i also have a 5w50, its 5wsomething atleast. Should i try it? Does all kind of oil work(read not destroy) but with various results?

What is it that happend if the oil is too thick or too thin?

 

[marcusgunby]

All oils will work-none should damage -its just a question of the most suitable oil.Make sure the oil you have doesnt have friction modifiers in it(alot of the thinner ones do)

 

[A-RustyDemon]

Well if the oil thins out to much it will not offer any protection. It the oil is to thick it will have excessive drag.

Here's a oil/temp chart

( 5W30 / Below -20* C --- 0* C ) ( 10W30 / -10*C --- 40*C ) ( 20W40 / 5*C --- 45*C )

With that info you should be able to pick the right oil weight.

 

[pyromaniac]

Originally posted by A-RustyDemon
Here's a oil/temp chart

( 5W30 / Below -20* C --- 0* C ) ( 10W30 / -10*C --- 40*C ) ( 20W40 / 5*C --- 45*C )

With that info you should be able to pick the right oil weight.

Sorry but i dont understand that temprature really. Are the two figures supposed to be celsious and farenheight? If so then i guiss i understand otherwise not.

Also how would you calculate how the outside temperature affects the gearbox temperature. I think its pretty big difference if you say, trail ride in the woods on a dry surface from what i do now. High speed ice/snow riding with snow constantly spraying on the bike.

I guiss the only way is to try what works the best.

 

[A-RustyDemon]

The temp is Celsius ( Below -20 C thru 0 C ) for 5W30 oil
(-10 C thru 40 C ) for 10W30 oil
( 5 C thru 45 C ) for 20W40 oil

These are recommended operating temp's for each grade of oil. You said your temp's are around -25 C.. So if you used a 5W30 oil or ATF type F transmission fluid you should be in good shape.