Mixing oil and coolant on yamaha sniper

It may be but also could be (cylinder---head----case) crack---- other issues a broken or loose headbolt---things that could cause it----accident---overheated---severe abuse---neglect---factory defect---sabotage---here's a bunch of issues/answers I found---you'll have to do a little searching through the answers as there are many.
https://www.google.com/search?q=2002+yamaha+r1+specs&rlz=1C1NHXL_enUS713US714&oq=2002+Yamaha+R1&aqs=chrome.2.69i57j0l5.6175j0j9&sourceid=chrome&ie=UTF-8#q=2002+yamaha+r1+mixing+oil+and+coolant

if you are using coolant oil (do not mix with standard water base coolant!!!), you need to use same brand and specification (type), best way is to check in your manual what type of coolant will be accepted, and then top it as required.

if you wish to change to another brand or to water based (or from water based to oil) then follow this procedure:
1. run engine for 10 min
2. very carefully open the fill tank and cap, drain whatever is in the system (watch for hot steam/water backflush!)
3. fill about 15% to 20% with new fluid and run for few seconds (flush),
4. drain again and fill with new oil, coolant or whatever you will be changing to.

buy extra liter so you will have for top up.

hope this will help you solve your problem - do not forget to vote!

Try www.bikebandit.com/
Or go to yamaha for the OEM parts.

This sounds very much like a blown head gasket. It should be repaired immediately to avoid engine damage.

Charlie

Many coolant makers have a "pre-mix" already blended. It's the easiest. Straight coolant should be 1/2 coolant to 1/2 distilled water.