lizard821000 wrote:stop posting and get to some bars, mama sans for sale.

I don't bother the bars and they don't bother me.

I had an nc 30 that made 45hp on a dyno and it was traced to a bent inlet valve on 1 cylinder.
I would guess you have a similar problem, 1 weak cylinder

marti wrote:I had an nc 30 that made 45hp on a dyno and it was traced to a bent inlet valve on 1 cylinder.
I would guess you have a similar problem, 1 weak cylinder

I see. Going back to dyno shop to get my a/f ratio graph and after that it's valve clearance, ignition diagnostic and carb setup. How did you find out about the bent valve?

krisztian_andre wrote:

marti wrote:I had an nc 30 that made 45hp on a dyno and it was traced to a bent inlet valve on 1 cylinder.
I would guess you have a similar problem, 1 weak cylinder

I see. Going back to dyno shop to get my a/f ratio graph and after that it's valve clearance, ignition diagnostic and carb setup. How did you find out about the bent valve?

Neosophist wrote:After you've set the valve clearances and compression tested it you'll know if it's worn inside / valve are leaking.

I got the a/f graph and it looks like a mountain range.

The power curves were identical between the two runs with the major peaks and valleys corresponding. what I'm saying is that the variations doesn't seem to be random. Can someone show me a close to ideal a/f curve for a bog standard jap spec NC30?

Your bike is running far too rich - get some smaller jets in it for starters.

Question is, why is it so rich when all it's components from the exhaust to airbox and jets are standard? Can it be carbon deposits on the valves or a clogged exhaust? Carbs are clean btw.

It can be rich due to atmospheric conditions. What altitude do you live at? What is the fuel quality?

There is no doubt it is far too rich. So, you make it leaner..which will make it more powerful, more efficient, cheaper on fuel and stop killing plugs...

I at sea level high humidity, 34 C temperature. It has 115 118 jets now, what size and brand of jets should I get?