Jump to content
Sign in to follow this  

06 CR250, Gear oil questions

Recommended Posts

OK, So I have this 06 CR 250, Ive been changing my gear oil after every ride and Ive come to notice that its not clear. It goes in golden and even after 1 heat cycle it comes out dark. Im using castrol 10-40 motorcycle oil. Im not sure if its the oil itself or if there is something else is wrong. Also the bike is like half fouling plugs. It will run perfect then if I'm not on the throttle wide open even for a very short period like less then 2 mins it runs perfect for the first 1/3 of the throttle but very rough for the rest of it. It can be cleared out but takes awhile and its not constant so I kinda don't know when its going to happen. Im running Klots super technoplate at 40:1 with shell 93 and have run it in the past on this bike with zero probs.

Share this post


Link to post
Share on other sites

Any oil you run will come out dark/black/grey after one ride. And as far as loading up sounds like a little bit rick on the pilot, maybe drop the needle a clip and see where that puts ya. What do your plugs look like?

Share this post


Link to post
Share on other sites

For starters, your gear oil will have no effect on what goes on in your engine since the transmission is in a separate compartment. Unless you have a bad right hand crank seal. Second, the oil in the gear box gets dirty quick because of the clutch. It definitely sounds like your jetting is a bit rich on the needle and possibly the main. Keep an eye on the plug with each change you make.

Share this post


Link to post
Share on other sites

The rapid color change in crankcase oil is normal on the '05-'07, and it's predominantly due to the ALUMINUM clutch plates. CHange the alum clutch plates to steel plates, and you'll see a 50% reduction in contaminated oil. However, going from alum to steel, you should see a slower revving engine, but in all honesty, only a pro racer is going to feel such a minute variance.

Share this post


Link to post
Share on other sites

i dont get people who change there oil every ride. the oil isnt even near broken down. wast of money and time. now every 5 hrs i can see. so give or take 3-4 rides(for me)

i do it every time, 5 hrs on the dot and never had 1 problem, even after 5 hrs to oil is still in perect condition. contaminated from clutch particals? yes, always. but still has all its lubrication qualities.

Share this post


Link to post
Share on other sites

The condition your describing could be a little jetting and fuel mixture. from factory they were jetted for 32:1 , 40:1 is leaner in oil, but richer in air/fuel!

Make sure your powervalve cables are ajusted properly and it does have the correct plug the 05-07 cr250's run a br9eg-n-8. I have run the br8eg with no problems , a slighty hotter plug! in the end you may have to jet slightly!!

Just remember it is a race bike and wasn't designed to lightly trail ride she likes to be wfo !!

Im one to change the trans oil every ride but that would a days riding! or a days racing, but to me it's not that the oil is broke down, it's the particles in the oil. fine metal,aluminium and clutch fiber will kill the life of trans bearings imo. I run a mag drainplug and it's a little fuzzy every change since the bike was new!

Share this post


Link to post
Share on other sites

Thanks for al the good info.. what's everyone have there needle set at? Also I'm running br8eg plugs would I do better going to a 9?

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×