Trying to gather ifo on the number & letters stamped on my Yamaha atv engine (4R-056}

ATV IS NOT A CAR NOR IS ATV A MAKER
IS THIS A YAMAHA WHY SKIP SAYING MAKERS NAME/?
RAD FULL OF MUD (AS IN FINS)
THERMOSTAT IS BAD.
SORRY CAN NOT GUESS ATV AT ALL, AND 300 SAYS ONLY ENGINE SIZE, TO ME. 300CC

You will need to find the VIN number stamped on the bear cat's frame. You should be able to use this to source the vehicles original details when it was first registered.
The VIN number is a set of 17 letters and numbers. The 10th digit is a code letter/number for a particular year after 1981.
**NOTE** From 2010 the letters are re-used so registration documents would be needed if the vehicle appears older than these dates.

According to your VIN Its 1997

The complete info from dmv is
Destination Market: U.S.
Make: YAMAHA
Manufacturer Name: YAMAHA MOTOR CORPORATION
Model: YFM400FW Kodiak 4x4
Model Year: 1997
Plant City: Hamamatsu
Vehicle Type: MOTORCYCLE
Plant Country: Japan
Body Class: Motorcycle - All Terrain Cycle (ATV)
Drive Type: 4WD/4-Wheel Drive/4x4
Displacement (CC): 400
Displacement (CI): 24.409497637
Displacement (L): 0.400000

They are usually stamped into the frame on the bottom left side, under the engine.

stamped on the side of lower frame rail below left footrest.

look for a vin number usually by neck our engine cradle--some have numbers on manufacturers tag

thats not enough characters to be a proper VIN you should have 17 numbers/letters and the 10th digit will tell you the year. The VIN should be stamped in the neck of the frame. If your find the whole number I can break it down for you.

Brian

most atv models have the spark arrestor built in them if in doubt check your muffler it should say the muffler case should be stamped with lettering saying it is US Forestry Approved.

you should have a serial code on it and within the letters and numbers it will have a kind that it is. research the numbers on line

its probably the same. check yamaha for a model number. usually something like YFM 350 and search for that service manual.