Another NC35 jetting question

[Mark-091]

Hi guys, just wondering if anyone ever confirmed that the flat spot in the midrange of the NC35 from factory is caused by it being too rich whereas the flat spot on the NC30 is caused by it being too lean.

My bike (NC35) has a full tyga system with 112s all round with standard induction and carb settings (original shims, float heights, mixture settings). It pulls very strong up top but still has a slight flat spot in midrange, exhaust tip is sooty, if you take the bike down to the coast where it leans the mixture off the bike runs perfect (with no flat spots), this is what is making me think that it is still running rich in the midrange. I'm thinking of removing the standard shims (so there would be no washers under needles) to lean the midrange off slightly but interested to know if it is rich or lean in the midrange from factory?

Has anyone run a standard bike on the dyno?

Thanks

[Drunkn Munky]

Yes ive had rvf's like this try a 0.5mm washer to see if your going in the right direction but also source some known standard slide springs as these may have been changed for hrc springs which are lighter resulting in a richer midrange. They're identical to look at so no way of telling, new air filter?

[Mark-091]

Hi Tony, Yep newish (couple of hundred miles) air filter, atm it has the original shims under the needles which I think are 0.5, I'm pretty certain that the springs are standard as when I bought the bike the soft screws etc looked like they have never been touched, also tried HRC springs that I got from Rick Oliver which made it worse. I was just curious if they ran rich in the midrange from factory? Just seems strange that other members are adding extra shims whereas I'm thinking of removing them completely.

[Drunkn Munky]

My mistake I thought they run 1mm shim as stock. Its not uncommon to run no shims my last rvf did yet my current one still has the shims and runs fine.

[Mark-091]

Cheers for your help Tony, I will run it without the shim and see how I get on. Still interested to know if they come with a rich or lean midrange from factory, suppose all bikes aren't the same but was just curious, it seems the majority of NC30 come from factory with a lean midrange.