YZ470...High Compression or Not???

Opinions are like......well.........anybody have some good solid opinions on what would be a better choice here.

I just got the cylinder done at Max Power and she is a 469cc now. I can go with a High Compression Wiseco 13:5:1 or a Standard 12:5:1 compression.

I use the bike to race a 30+ Vet series in Southern California and also trail ride. Probably put about 15 hours a week on it.

For fuel.......I do have a high octane (MotoSport 103) gas station pump right around the corner from me.


Either way, she's still a 470! :bonk:


I have a 13.5:1 Wiseco, only a 426 though. I can tell a big difference in bottom end snap and mid range pull with the higher compression. It will run off pump gas without pinging, but I run race fuel anyway. Downsides are that its a hair harder to kick start, it makes the jetting a little picky, and in long hare scrambles it wears me out faster. I'd do it again. :applause:

Thanks for the reply. Just curious on the race gas, whuddya run?

Get it dynoed and let us know how many ponies you got from boreing it out.

Have you tried that U-4 or the elf LMS fuel?

I use the elf LMS it works great, I think you should run the 12.5 piston and when you race use the oxygenated fuel and she should last longer.

Although my 05 likes a little richer jetting on the Oxy fuel.

We like the u-4 as well!Burns clean,no hint of pinging,and smells sooooo good!

On the pricy side but you get what you pay for i guess.Just be sure you drain the carb after each use!!! :applause:

Thanks for the reply. Just curious on the race gas, whuddya run?

Citgo 110 leaded. :applause:

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