What am I risking?

I just bought a 05 wr450 from a buddy. It has a Pro Moto Billet exhaust insert, the YZ throttle bolt, and the baffle has been removed. I'm assuming that from the factory it was jetted very lean to get it green stickered. Now that it is breathing better, as well as getting more air, I'm sure it is extremely lean. He rode it this way, is there any issues that may have occured already. Should I not ride it till it is rejetted? It has all the stock jetting settings currently with the AIS still installed and functioning properly.

Start by pulling and reading the spark plug.:mad:

there is no real risk other than performance. Check the plug to see if it is the residue on the end is whitish. If it is then you are lean, also if you are poping on decel and have an off idle bog then you need to re-jet.

The JD jet kit is the best place to start. after that there is a jetting data base sticky at the top of the forum that I'm sure you could find other around your area and see what they are running.

there is no real risk other than performance. Check the plug to see if it is the residue on the end is whitish. If it is then you are lean, also if you are poping on decel and have an off idle bog then you need to re-jet.

The JD jet kit is the best place to start. after that there is a jetting data base sticky at the top of the forum that I'm sure you could find other around your area and see what they are running.

Hmmm? Ive always been told that riding a bike wich sparkplug is white WILL be harmfull.. Since the reason for the sparkplug turnig white is extreeme temperatures there is a probabiliy for burning a hole in the piston.. correct?

Hmmm? Ive always been told that riding a bike wich sparkplug is white WILL be harmfull.. Since the reason for the sparkplug turnig white is extreeme temperatures there is a probabiliy for burning a hole in the piston.. correct?

your correct. however if he is running the stock jetting with airbox opened up, I wouldn't think that it would be getting to the point where you would cause damage. but I could be wrong.

just take out the ais and re-jet it..................then you don't have to worrie...

Reading a sparkplug with unleaded fuel is not like it was in the leaded days.

Reading a sparkplug with unleaded fuel is not like it was in the leaded days.

Your right. A white plug doesn't always mean its too lean. I would get concerned if it was breathing hard or plain doesn't run right....and unless you do the mods listed in the top of this forum, it will always backfire on decel.

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