400 rev limit

[koko64]

What's the safe rev limit for a 400SS/M400?

[ducpainter]

If it's anything like the other 2V bikes, it'll run out of power before you can hurt it.

Bruce always said that with a stock 2V motor anything past 8500 was just making noise.

[koko64]

Yep, sounds right. There was a red line on the tacho at 11,000. The owner said she regularly revved it to that. Maybe its good we didn't buy it.

[Charlie98]

Yep, sounds right. There was a red line on the tacho at 11,000. The owner said she regularly revved it to that. Maybe its good we didn't buy it.

[Speeddog]

Factory rev limit for a 620 is 10,400.

Given the 400's shorter stroke, it gets to that same average piston speed at 12,500, and same piston acceleration at 11,650.

Considering smaller pistons and smaller valves, a bit safer at those revs.

These go to eleven.

[koko64]

Cool thanks. The bike looked ok but for some cosmetics. Mighty Mouse is going to haggle.

[DarkMonster620]

if not, punch it out of the owner

[koko64]

 

[Speeddog]

My memory is slipping.

http://bradthebikeboy.blogspot.com/2016/04/it-does-indeed-go-to-11.html
Likely the only 2-valver that is *worth* taking past 8,500.
Not that there's that much in it, but if it only makes 37HP sometimes you've got to have it all.

If the one you're looking at is a carbie, then not likely worth taking it past 8,500.

[koko64]

Cool. Thanks. Little zingers!

[koko64]

Mighty Mouse walked away from a pretty little 400SS. She says the Monster looks tougher. The kids have settled on buying an M400. The low seat height, ergos and bar leverage have sold them on that direction. I was considering 250-400 motards but my babies are only 5'2" and they want a Monster! Must have raised 'em right.
Eyeing off a yellow one at present. So back to plan A on my long term 900 project.