Ok... I have been out of the loop for a bit but I'm back now for an undetermined amount of time.

I posted this thread in the ZX9 section but was looking for more exposure on the subject.

I've had my '95 ZX9R for a short time now. I sent it to the shop to check the sync on the carbs, a rejetting, k&n filter, a full service and new tires.

The shop has a dyno and they ran it when they were done. The result was 112 HP at the wheel. That doesn't really seem correct. The bike is supposed to leave the showroom floor with 138 BHP. Could I really be loosing more then 26 HP at the rear wheel? The graph was super straight and it runs extremely well, it also has tons more power then previously. The tech said all but one of the valves was way off. I went with a 170/60 Michelin Pilot Power rear tire instead of the 180/55 stock tire. I should have lost a pound or two there, that could only help. The chain and sprocket are original but in like new condition. The bike only has 13,000 miles on it. It has barely been used.

Anyway, ideas or opinions are welcome.

 

This sounds about right to me. Most "listed" bhp figures are for horsepower at the crankshaft, and a 19% loss for drive train, etc. doesn't seem excessive. I don't know if you are getting your figures from published company data or from comparitive testing done on other ZX9-R's, as I never had mine dyno-ed, and the seat of my pants isn't as good a judge of character as it used to be.

 

Okay...you got my curiosity aroused. I went back to my old MotorCyclist pile and dug up some numbers they had run on a dyno for the ZX-9R. Their figures showed a dyno number of 125 bhp at the rear wheel. Sounds like your 11 year old bike dyno-ed at about 11% less than MC's new test bike. It did not mention in the numbers whether they were using a freer flowing air filter or not (or whether they had made ANY other mods at all).

 

Right on.

Thanks for the intel. My stock numbers are coming from published company data. The recent dyno is after the tune up and mods. Your last post is making me desire a second opinion. I may have to track down a different dyno in the Atlanta area and see what they come up with. The numbers I got I would expect from a stock set up. The bike isn't stock.

Maybe Kawasaki was being optimistic with their figures back in '95. I'm going to follow up on that with a different dyno test.

Thanks again.

 

Maybe Kawasaki was being optimistic with their figures back in '95. I'm going to follow up on that with a different dyno test. - BattRECON

THAT I would not doubt in the least. Kind of like ammunition manufacturers' boasts of velocity figures. After reading some of those, and then chronographing different loads, I quickly found that they must have been using 30" barrels and a LOT of wishful thinking.

After reading the actual dyno figures from MC, though, I would think you should be getting a few more ponies from your steed, though. Am glad to hear that at least the bike performs well and has a good, usable torque curve. I guess I've come to the point in my life where getting the highest number no longer matters, as long as the tool does the job. (Lordy, in more areas than one. lol)

 

when i bought my first zx9... it was a 2001... it was very stock... i took it straight into the shop and sure enough... 121.. rear wheel HP.
exactly what kawasaki said... im also pretty sure.. that the 01 had more horepower then their previous years.. they took the older motor, did some engine work.. blah blah blah... point being is i really think your bike's bhp.. is about right.. are you sure it wasnt hp at the crank..?
your bike seems stronger.. because of the valve adjustment... and i hope he didnt make them to tight... alot of guys go tighter on the valve shims. Racers mostly.. it of course makes for better top end hp.. i wouldnt say it takes away from the bottom end, but the bottom end isnt as "throtle smooth" wich racers dont really need...

if your bike runs good, is responsive at the wrist... leave it alone.. hp doesnt mean a thing.. its ***** and experiance that makes a bike go fast...
oh and loose that 170 series bicycle tire

 

Well, I took it to the mountains again today. It really runs flawlessly. The throttle is super smooth and I have yet to notice any flat spots. It has a huge amount of power, plenty to throw the '400 plus' pound bike around. The numbers are definately from the wheel.

Think I'm going to take motogp's advice and leave it alone. I think after this next deployment I'm going to convert to carbon fiber rims. I'm also going to replace all the plastic panels with carbon fiber as well. Wouldn't hurt if the bike lost some weight.

For the record I can't tell the difference between the 170 and 180 wide tire. Doesn't seem like 10mm made a difference with power or handling. I think I'm going to go back to the 180 just for aesthetic reasons.

Thanks for your help gents.

 

Your numbers for you dyno might be right for the type of dyno they use. It's like that for car's there are a bunch of different type of dyno's out there so you might want to try again on a different type of dyno.

 

If the oportunity for a different dyno comes up I'll definately run it again. At this point I'm happy with it so I'm not going to actively seek out another run. I have a friend in the Army here in GA and she has been asking if I know of any motorcycle dyno's in the area. I have a feeling that when we finally get around to running her bike I'll probably run mine as well. When that happens I'll reserect this thread and post the results.

 

sounds good BattRECON