My first impressions on the 400… and a few ??

The bike went through MOT here in Switzerland and they couldn’t fault it!
Not bad for a bike that broke a chain 2 weeks earlier! I am now using it everyday.

Gotta say: I REALLY like it! Probably one of the best vintage bike around. It is really up there with my T20, the Kawasaki A1 & the Rz500. Bikes that I will have a hard time to sell

I really like the torque down below and the screaming top end. I might still have some carb and iggy realted probs, but the infamous 3’500k flat spot is really gettin’ on my nerves.

Was it really a “feature” of the bike when new? If so, I am amazed yamaha managed to sell so many RDs. As i said, less-that perfect timing & carbs might make it worse, but everything is set std.

Is the RZ/RDLC rubbers block with cross-tubes the solution?, if yes what jetting do I need?

I can’t afford a speed fine in town, it’s lethal here!

EDIT Answer from johnB from the ACRD Forum:
Standard the mid range stutter /flat spot shouldnt be too bad if the timing & carbs are set up right.The E/LC or powervalve rubbers with the ears cut off & the crossover tube will make it better.No jetting changes needed.6mm reed block spacers also help beef up the mid range a bit.
ps. if you think the standard stutter is bad I don’t think you’d like a bike with expansion pipes/k&n’s!