Trading my CBR 125 for a 1999 GSX-R 600.

The previous owner drained the synthetic oil out and put in normal oil without flushing it. It has only been driven about one kilometer since.

What would the best course of action be?

Thanks.

Ride it

Ok.

Now let's say I want to remove the new conventional and replace it with synthetic?

ride it

ride it

Step 1. Drain
Step 2. Fill
Step 3. Ride

Easy as 1-2-3!

The old "you can't go back and forth" thing is a wive's tale. You can switch back and forth with no issues.

ride it

CBR 125? Really?

Given the topic, methinks I smell BS.

http://www.hoc.org.uk/gallery/bikes/CBR125_2005%282%29.jpg

not everyone lives in america.

i would really like a cbr250rr :bounce but they are super rare here since they have to be imported.

http://blog.goo-net.com/ninja636r/img/360/CBR250RR.jpg

Only difference is the molecules are smaller on synthetic oil, so if you have a high mileage engine, the likelihood of the synthetic "finding" leak spots is greater than conventional oil. At least that's what I heard years ago. Maybe different now.

I used synth in my former turbo car because if it is shut down before the turbo has a chance to cool, the oil can "coke" up on the turbo bearings causing a varnish to form, and early failure. Synth oil wont "coke" up, it turns to ash when cooked like that. So, longer life turbo. But even with synth oil I still used a Turbo Timer to shut the car down automatically.

The old "you can't go back and forth" thing is a wive's tale. You can switch back and forth with no issues.

Not always the case....I agree completely with you when it comes to NEW engines...but if you take a high milage car that has always run normal oil and then switch to full synthetic your bound to run into problems...

Im having this issue with my truck right now...My dad and i have been running normal oil in it since 20,000 miles(1997).. I thought it would be a grand idea to put full synthetic in it at 277,000 miles (current) and im having some pretty big engine issues right now. :crying

Not always the case....I agree completely with you when it comes to NEW engines...but if you take a high milage car that has always run normal oil and then switch to full synthetic your bound to run into problems...

Im having this issue with my truck right now...My dad and i have been running normal oil in it since 20,000 miles(1997).. I thought it would be a grand idea to put full synthetic in it at 277,000 miles (current) and im having some pretty big engine issues right now. :crying
And what kind of "engine issues" has this synthetic oil caused? :wait

And what kind of "engine issues" has this synthetic oil caused? :wait

anal leakage reminiscent of the bp oil spill - true story!

Thanks guys.

And what kind of "engine issues" has this synthetic oil caused? :wait

not quite sure yet i havent torn it down. It could just be time for a rebuild with as many miles that it has on it. Stong engine though 5.9L 360.

not quite sure yet i havent torn it down. It could just be time for a rebuild with as many miles that it has on it. Stong engine though 5.9L 360.

I can tell you one thing. No mechanical problem you have was caused by changing oils.

I agree, ride it and have fun.

...Im having this issue with my truck right now...My dad and i have been running normal oil in it since 20,000 miles(1997).. I thought it would be a grand idea to put full synthetic in it at 277,000 miles (current) and im having some pretty big engine issues right now. :crying

And this couldn't have just been coincidental? :scratch

Im currently using my bike full time and the weather in texas is...well its always hot. I plan on starting on it this next month. I need to take is somewhere to do a compression test but its not the easiest to tow...http://i868.photobucket.com/albums/ab244/wuzup76020/truck.jpg

I would just ride it with that oil for a couple thousand miles then replace it. If it really worries just replace it now, you won't have any problems mixing.

The engine has no idea if the oil is syn or dino, also there are lot's of semi syns out are a bled of dino and syn.

The most important thing is you change the oil and filter regularly.