Is 1987 Kx 250 motor same as 86 kx motor?

[cavemanbob21]

Found a whole 1987 KX 250 parts bike for sale looks same as my Tecate motor thought I read somewhere that they were straight swap but cant find that info now can someone enlighten me before I pull pin on buying it? Thanks

[Dirtcrasher]

I did a search but used Google and punched in "3wheelerworld KX25o Tecate motor swap"

1) http://www.3wheelerworld.com/showthread.php/94809-Kxt250-Tecate-3-What-Parts-Fit-Swap-Interchange
2) http://www.3wheelerworld.com/showthread.php/66055-Tecate-engine-swap-amp-build-thread
3) http://www.3wheelerworld.com/showthread.php/182841-KX-250-Motor-VS-Tecate-250-motor
4) http://www.3wheelerworld.com/showthread.php/189087-Kx250-motor-into-a-tecate-3
5) https://atvconnection.com/forums/kawasaki/22271-tecate-3-a.html
6) http://www.3wheelerworld.com/archive/index.php/t-69008.html
7) http://www.3wheelerworld.com/archive/index.php/t-166563.html
8) http://www.3wheelerworld.com/showthread.php/160626-First-Gen-Tecate-engine-swap-with-newer-KX-engine
9) http://www.3wheelerworld.com/archive/index.php/t-117395.html
10) http://www.3wheelerworld.com/archive/index.php/t-28221.html
11) http://www.3wheelerworld.com/archive/index.php/t-40474.html
12) http://www.3wheelerworld.com/archive/index.php/t-61355.html

I didn't read any of them, something has to be helpful and there are more links out there...

[christph]

I think the physical dimension are the same but the engines are different. The KX got a different power valve in 87--like the T4. It probably got port timing more suited to bikes and gear ratios too.