FZRSupport: the FZROnline Archive

I have spoken to busters bike shop about ordering a chain/sprocket kit, they say they only do 520 conversion kit for my bike and the ones for the other fzr400s won't fit. Other sellers say their kit fits the 2tk but when i ask it turns out it doesn't have 41 teeth.

I have looked at previous posts but to be honest I don't understand them can someone tell me what the 520 conversion is? or i'm i correct in thinking it is just a thicker chain? and is it a straight swap? or would any yamaha 525 chain with sprockets 15 front and 41 rear fit? and would the sprockets from the other fzr400s really not fit?

Please help and if you could make your answers as simple as possible because this is my first project and I'm just learning as I go on.

Why would you want to move to a thicker, heavier chain? Most people do the opposite and go to a lighter chain to reduce rotating mass.

The thing is I have no understanding of this so if someone could explain it to me that would be great.

Both the fzr400s and fzr600s have the same countershaft so either front sprocket can be used as long as it is the same pitch as the chain you are using. All the fzr400 rear sprockets will work, again must be same pitch as the chain you are using(600s won't fit). the 520 and 525 chain have the same pitch but the 525 is a wider chain (so the 520 should be a lighter chain). it's best to use 520 sprockets with 520 chain, using 520 sprockets with a 525 chain will allow the chain to wear the sprockets faster.

Brilliant, thanks for your reply that all makes sense....but now I've noticed the engine number is different to the chassis - so trying to find out what it is from.

Just for greater clarification, the first digit, in this case a 5, represents the length from center hole to center hole of the chain link. The 5 series is 5/8 of an inch, the 4 series is 1/2 inch. The other two digits, 20 in this case, is the thickness of the roller which is 1/4 inch.

Obviously, the 4 and 5 series sprockets and chains cannot be interchanged.

tno45 wrote:Brilliant, thanks for your reply that all makes sense....but now I've noticed the engine number is different to the chassis - so trying to find out what it is from.

tno - what number is stamped on the engine?

I have a 3TJ and a purported 2TK motor. Both stamped with just "1WG" ... Not real helpful in the ID department.

RoadDogma wrote:I have a 3TJ and a purported 2TK motor. Both stamped with just "1WG" ... Not real helpful in the ID department.

Where are you seeing that prefix? My 1WG 400 motor is stamped 3BF and the 600 is 3HH (top-side / right-side next to the clutch cover).

It's not a prefix. That is the entire string stamped into the crankcase (top/right side, above the clutch cover). (Same place as the serial number on my U.S. 1WG motor). Remember both of the 3TJ and 2TK motors came here by way of Europe. I guess they do things a little different over there.

RoadDogma wrote:It's not a prefix. That is the entire string stamped into the crankcase (top/right side, above the clutch cover). (Same place as the serial number on my U.S. 1WG motor). Remember both of the 3TJ and 2TK motors came here by way of Europe. I guess they do things a little different over there.

Got it. No serial number, per se.

How about some more fun with numbers? Wanna pull the valve covers off of your YZF motor and tell me what number you find on the cam bearing caps?