It's also made (making
) 10 less than that just from being setup a tad on the too safe side and being ragged round dozens of track days and races for the past 2 years, so don't underestimate the gain from a fresh top end (or more to the point what you'll never make if the top end is 15,000k's old) or jetting for the day.
That graph is pretty much as I got it back from Apex;
Fresh top end, replated, new stock pistons, rings etc. SP barrels and heads, stock (0.5) base gaskets
Open airbox, i.e. no lid, filter wired in place (IMHO it felt better with a modded lid, never proven on the dyno)
HRC 030 card
Tyga pipes
HRC jet kit (2nd clip - i.e. one leaner than middle - B needle, 188/190 mains, no power jets)
Everything else stock, that was close to the edge though and did just seize one cold day.
So 60bhp is easy if you get the HRC card, all but impossible without it;
My current road '28 runs;
Stock (but maybe old) '21 entire engine (inc flywheel), stock derestricted pipes, modded airbox, stock Honda smartcard, bearing in mind I know exactly what 53bhp in a ripped down race/trackbike bike feels like I'd guess the road bike which is probably 20kg heavier is making maybe 50-52.
I'd be impressed if you saw much over 55 with the stock card (on a dyno that shows a stock derestricted '18 at 62) but if it's completely standard it's only making 40, and it's a rubbish 40 too, unlike a nice screaming banshee gp125 40, it'll make 36 of them at about 8000rpm then it just throws the towel in and limps round to the redline.
But all is not lost;
Firstly, get those exhaust pipes off and see if the headers have (what look like) big washers welded in them, they will look like one of these;
The top one on the left is how it should look, the bottom one on the right is stock '28 and not the way forward if you don't want to be whipped by L plated Aprilia RS125's ridden by crazy kids with no gloves.
Loads of time with a dremel or the best part of £400 (+tax, post etc) Tyga's way is the answer here. Jap4Performance probably have the pipes and cans in stock in the UK (hint, become a titanium member of this site and you'll get 10% off at Jap4, more than covers the cost of the membership if you buy the pipes and cans).
Airbox, Tyga mod the lid like this and will sell you one done if you want, nice if you want to keep yours intact. But we've seen good results from 4* 1.5" holes drilled in the top of the lid. Whatever, plain common sense tells you airbox inlets smaller than the carbs isn't helping the cause.
MC21 flywheel, worth a horse or 3, I'll bet Andy will sell you a lightened one if you ask nicely, that'll give it a tad more bing too, which is nice, order a flywheel puller from someone while your there, Tyga do them.
That will (if set up right, don't just do that lot and run stock jetting!) be a lot better, it'll still get spanked senseless on the track by an RS250 Aprilia with some pipes but as a road bike (IMHO) it's enough.
Anyway without taking a Dremel to the porting it's about as good as you'll get running the std Honda card. Tyga did it all here.
Want more?
Then that stock card has got to go, pains of running an HRC card and details of what you have to do here, details of the wiresplice here and here.
Pains of obtaining an HRC card may be more involved, Honda have discontinued them, you may need to track down a matching PGMIV as well (or ditch the lot and run PGM II, III, F3 stuff, RS stuff etc, depends how commited you are).
Sort the ignition out and it's no different to any other NSR to tune, ported, optimized squish, setup carefully and you'll see the best part of 70bhp.
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Last edited by fontyyy on Wed May 21, 2008 7:36 pm; edited 1 time in total