Got my XR650R on the dyno today!!


I got an hour's worth of dyno time today and was pleased with the results. Here's the mods to my bike:

2002 XR650R, White Bros header, "E" Series pipe with 12 discs & quiet core insert, side panel cut and screened, UNI filter with no backfire screen, XR's Only cdi, Edelbrock carb (recent sale fell through) #21 needle installed in Edelbrock.

My bike ran 51.0 rear wheel hp. The only other XR650R ran at the shop had a HRC kit (cam/piston) and ran a best of 57 rear wheel hp.

I understand there is a difference in dynos and operaters. BTW, this was done at G-Force Performance in Santa Clara. They specialize in import street bikes and have never used an Edelbrock carb before.

I would think the quiet core could cost an hp or 2...but I am no pro

just my 2 pesos...

Well, I just ordered a new chain and sprockets for the bike. Hopefully I can get another run in after the install. After searching the forum I ended up buying a DID chain.

I'm curious . since you have edelbrock, AND if you do some roll on accelleration grafs. Could you turn in a click or two in and do a run and then do another run with a click or two out from original setting. Wanted to know if curve gets stronger or weaker in different sections or does the whole curve show a parrallel weaker line. My QSlvr seems to run best rich for just off idle but breaks up cruising. When leaned out ,to rid breaking up, it seems to loose low end grunt. (even if pump is increased)

Is there a huge increase in power with the edlebrock over stock card with same mods?

@ what RPM did you hit 51hp?

What was the HP @ 3000 and 4000 RPM?

Bork, interesting you mentioned that. The graph showed my bike rich at idle, lean in midrange, and okay at top end. I ended up leaning out the needle a few clicks and richening the pump adjustment. What I found suprising is the dyno guy suggested I go to the next richest needle for the top end. I haven't heard of anyone with a 650 running a bigger needle then the #21 and it sounds like several people with 680cc kits are still running a #19.

Sportbiker, I didn't run with the stock carb so I don't have proof. I can tell that I still had more low end with my stock carb and defianetly noticed a smoother, stronger pull from mid range on with the Edelbrock.

BTW, looks like the difference between my bike and the HRC equipped bike was that I run a header and had bigger cut-outs on the side panel.

For anyone interested, the power curve was super smooth up to 6700-6800 then dramatically fell off. Looks like the rev limiter I have right now doesn't do anything for me with the stock cam.

I want to dyno run my bike for this reason of fuel curve . My impression is, it could be better. my bike is a 94 xr600r. stock and uncorked. I run a #17 needle (i think). I've tried both higher & lower. I'm tempted to make a flow bench and try and custom grind or polish needle for my set up.

sportbiker , there used to be a graph from a dyno run on the old forum. I'm sure it is around somewhere. If memory is correct it was maybe a 2 hp gain . But the plus of performance is snappier response without ,sneeze/cough and ( I noticed was after wipeout )easier start and will keep running on its side. (just pull in clutch ,pickup bike and hop on, and go ! My .02

What about peak torque?

I have the same mods without the header pipe or CDI.



wow, that makes me happy, i must be doing about 58 hp with my wimpey L

Jackattack and Twor's,

The operator said his printer wasn't working but my info is saved in his system. I do not recall what peak torque was or at what rpm max hp was at.

Hopefully I can pick up the info soon.


Optimistic dyno...


Optimistic dyno...

It sounds like the dampening (smoothing) setting was set way off to get the big numbers. Both readings are 5+hp high for both bikes. It's amazing to see a stock HRC engine put out more rear wheel horsepower then Barnum's Baja 680cc Race bike! :p And a stock bike with a quiet core muffler putting out more horsepower then a HRC engine! I need some of the fuel they run there :applause:

But, then again Edelbock and Barnum might not know what they are talking about when they say they have dyno'd the XR650R in every way and there is no way a stock bike can put out more then 49hp and a HRC 52hp. That HRC is putting out the same horsepower as a 680cc, stage two cam, oversized intake valves bike! :eek: Must be running nitromethane. Dyno's that are certified calibrated will be only .5% different form each other or less. I had my bike ran on two dyno's (one certified) and they were .4hp different. That is less then half a horsepower different. Most Horsepower out of a 680cc engine built to the moon was just near 59hp to the rear wheel at Edelbrock. I was going to run my bike at Dyno-Dudes again but, I think I'll drive it down to this dyno....I'll get way better numbers :)

Maybe a naive question or two, but ...

Do you run your bike on a roller dyno with knobby tires?

Would it make any difference with slicks? or is the traction or lack of compensated for somehow?

Just curious.

Wow. I feel like I'm getting flamed by particular people for sharing my experience here. I recall acknowledging the difference in dyno's, settings, and operators. However, the other XR650R WAS run on the same dyno by the same person. I don't believe the HRC equipped bike was up to it's full potential with the stock header and slightly modified side panel.

I think I'll drive it down to this dyno....I'll get way better numbers :applause:

Lighten up BWB63.

It's probably the same dyno the CRF450 guys are using to get 70hp, by adding a carbon fiber pipe. :eek:

I am not flaming anyone. Not even a little.

First, 680cc Baja race bike getting 57 rear wheel horsepower. This bike came in fifth over all in the Baja 1000. My bike is a 680cc biggest free flowing header/muffler oversized intake, bored out to 42mm Edelbrock, cam. I get right at 58hp. Both bikes with street tires, (no knobbies) rolled on in forth gear. There is a whole bunch of guy's that have posted their charts of their HRC XR650R's getting just over 51hp. These are just what has been actually put on the net for all to see. My bike dyno'd twice (one on a state certified dynamometer).

The nice thing about "this" dyno you used, is it is consistently over 6hp for both bikes ran by the same guy. This does show something. There are lots of dyno charts out there from stock bikes with header/muffler, pumper carburetors that get 47~48hp. I had a dyno chart from a stock, tuned dead on XR650R, Mikuni pumper, XR's only header, R4 muffler, Uni air filter holes in the side cover and I got 48.2 rear wheel peak Horsepower. You can change the numbers by changing the smoothing or dampening, snapping the throttle, instead of rolling it. Running no air filter, race gas. Not a flame just a heads up that this stock bike of yours is putting out the same horsepower that others are getting with there HRC $$$$ bikes and this other HRC bike is right there ready to best the Baja race bikes. When I went to the dyno shop I told them I was going to compare the dyno reading to another dyno and I wanted real numbers. They didn't know the others numbers and they came out within .4hp of each other. I did change the air filter. Now I am talking different cities, different operators and coming up with the same point; real dyno's ran by real operators will get close to the same numbers, not more then .5% off. The readings for these bikes you talking about are 12% different from any other California XR650R dyno run. That is not a flame just some facts. Your bike is tuned and that is great and I didn't want to thrash your big numbers that you paid for. It would be nice to see the chart and thank you for sharing :applause:

Be less defensive, there is only the attitude your are reading into it. I meant it, I would like to drive down there with my bike and find out what big numbers I can get to see that if there are dyno guys that pump up then numbers to make the costumer happier....for some that is all that matters are how big the numbers are. Not, if they are real or not.

It is cool that you got your bike to a dyno, no matter what the numbers.

The figures are interesting and I'm glad you posted them.

The real value of dyno tuning is to fine tune your bike so your bike runs it best.

The only figures that really matter are the before & after in relation to eachother.

Who cares whether it says 45hp or 55hp? It is no practical use to compare figures from different dynos. There are so many variables.

I took my old Moto Guzzi to a dyno shop a few years ago and was amazed at the difference the tuning made as compared to my "seat of the pants" tuning. Way smoother, way more torque, more hp. What this means is that my tuning was amiss.

So forget about the nominal numbers, just concentrate on the the relative numbers to achieve your goal of your BRP running at its potential.

Do let us know your final set up, though, it could be a could starting point for folks with similar configurations.

Since I'm a conservative trail rider, I rarely use all of the BRP hp anyway, so top hp is a little irrelevant to me, though I'm addicted to the torque.


My comment was a little sarcastic, but not meant to flame.

Desmo is absolutely right. At the end of the day the number is irrelevant, it's how the bike runs that matters.

With my racecar, tuning the carbs on the dyno yielded a 40hp increase at the wheels. That was just jetting changes and fine tuning.

My XR in it's old configuration had an awful lot of development and dyno time in it. In the end it was one of the strongest bikes of it's configuration I have come accross (actually riding, and online). It was a full HRC motor, Ti Arrow exhaust, lots of tuning, etc. Best dyno reading... 54.1 hp, 48lb. ft. torque.

I haven't dyno'd the new motor but I can tell you it is MUCH more powerful.

Do I really care what the number is? No.

Do I believe the numbers you got are accurate? No.

Does it matter? No.

If your bike runs well and makes you smile that is the bottom line.

One more note on dynos and comparing #'s...

All dynojet dyno should be fairly close if opperated correctly.

It is widely accepted in roadracer tuning that the dynojet is not particularly accurate when determining real power output. They read high.

The Factory Eddy Current Dynamometer is the one to check out.

If you have a few minutes take a look at their site. Check out the link to the dyno info then also look at the link re: "true horsepower".

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