Dyno Run with different caruberetors.

doesnt surprise me...the supior atomization of the edelbrock!

very cool you guys did that!

just curious--which dyno? is it the edelbrock dyno? i need to do the same with my 680 one of these days...some dude on the yahoo site got in my face on this subject awhile back...wish i had your numbers to shove up his a$$...

keep it coming, Bruce!!

Anyone know of a Dyno shop in the Moreno Valley, Redlands, Sanbordo area? I would like to get a chart to compare so, I can show different Dyno's with the same bike the same way.

Yo Bruce,

I have a weird question for you:

I'm asuming you guys dialed the Edel. carb in while it was on the dyno, in order to achieve the best performance.

Did the carb need adjusted from your "seat-of-the-pants" testing compared to the dyno testing. :cry:

If so, how much was it off, and in which direction(leaner,richer).

Please let me know if you don't understand my question, kind of hard to write it.


It was two clicks to rich on the needle clicker and way off on the bottom pumper adjustment. The engine needs more pumper then the carb could give. It is real close though...if it was just a little more. Remember this isn't a stock XR650R.

thats REALLY interesting...

for max power it makes sense to have it lean--but did it pop on deaccelleration?

did Rob say anything about having a bored out edelbrock for the bigger eninge?

Both my bike and his now have a bored out Edelbrock on it. I think that's what you are asking.

We did the test stock Edelbrock and messed with it till we got the highest numbers. (about 55+hp) Then He (Barnum) bored the Edelbrock to a 40mm X 42mm venturi. He has the 40mm X 42mm venturi and a 18 needle (leaner then mine at a 19) and he has plenty of pump left. Enough to kill the bike if he gives it a few pumps at rich.

After testing mine (just a little drier weather) I'll mess with the Mikuni again and see what I can get out of it.

I reading through all the charts/info I didn't see a dyno run to compare the Edelbrock to the stock carb all things being equal. Given a stock bike fully uncorked does the Edelbrock produce more HP then the stock carb or are the benefits easier starting, tunability etc.. :cry:

we spent so much time messing around, that at the end Barnum was real late for a promissed appointment.....We forgot to print that one or it got left on the desk. I know the torque numbers were higher. I will ask for them next time he is down there. Maybe Irondude can pick them up if he is going down there soon?

i would like to do that but not till after the 1000-to busy.

The edelbrock website has numbers on HP gains vs stock. Its about 1 hp or so...but of course theres lots of variables.

The main gain on the edelbrock is starting, off-idle response, increassed milage, external tunability, self-adjusting for altitude, and it will run on its side...

Plus it has an american flag on it!

KTM now sources from GPR in San Diego for steering dampners/stabilizers--can you imagine Honda sourcing from USA Edelbrock for pumper carbs?

Someone should start a dirt bike motorcycle company in the 909. So many suppliers of supior dirt bike components out there...set it up kind of like ATK, TM, VOR, Vertemati or Husaberg.

Call it 909 Motrcycles---make a 250 and 450 dez, MX, DS, and SM all on one platform with two cylinder sizes a la KTM. Then a 690 dez, DS and commuter bike.

Two frames, two engines, lots of locally supported components...edelbrock carbs, IMS tanks, etc. etc...

Anyone got $3-4 million and a wherehouse in Corona?

How about a whorehouse in Michigan?

Do you or Mike Kay :cry: have any Dyno charts that were or were not on this same dyno? What are the feelings from you guys :cry: of these and the other numbers that are thrown around for our bike. The numbers don't make it go any faster but, I sure have gott'n alot of feed back on my 'e' that isn't very good. The problem is most just want to see big numbers! I have gott'n 'e' mails from "bad Dyno" to the bike wasn't "tuned right". 16 "E" mails in one day just going off that the XR650R has to be able to put out more then 65hp! Comparing it to the Horse power output of a single chevy cylinder...all kinds of stuff. This guy from Belgium (Europe), even sent me his dyno charts to set me straight. I have also been a pian in the butt, in the past just looking at numbers, I have tried to point out that all the numbers were low (compared to what others get) from stock bikes getting 34hp, Un corked 43hp and stock with all the extras getting just under fifty. You have you both :lol: have riden Barnums bike and it's "only putting out 55hp??? I don't think they get much faster???? Do they???? Lets hear some good ol' Ironman putting it straight talk :cry: :cry: :cry:

Here is the Belgium (Europe), dyno chart.... IM001184.jpg

Well -- i think everyone is right.

Dyno's are ALWAYS different. Its impossible to accurately compare one dyno's results to another.

Rob Barnum often uses the Edelbrock dyno--(but i dont know if that was used for Bruce's engine?) anyway--that unit is a bit 'lower' in terms of the numbers of horsepower acheived. SO if the Edelbrock dyno says 55 its very reasonable to say another dyno can give a result of 60 or more. Very common. In fact that is the norm. The exception is for 2 dynos to give the same number for the same bike.

Of course other things like rear wheel horsepower vs crank or different atmospheres or other variables can play with the numbers as well.

Can the XR680R with 11.5:1 and a 40/42mm edelbrock, kibblewhite head, etc, be beaten?

YES! -- but it wont last long. For SM there is the option of turbo, a 710 bored and stroked motor, changing the rev limiter, etc.

BUT for an engine that will get ya thru the race season--or finish the Baja 1000--then its going to be hard to beat the Rob Barnum XR680R like the one Bruce (and I!) have. Bruce has the bigger valves and the higher compression.

To finish the Dakar Rallye i decided (well--really it was Rob's idea!) to go with 10.25:1 compression and a balanced crank on the 680. Just FYI both Bruce and I run the carilo rod and kibblewhite valve train. I added the HRC cam chain and we both have the mid-grind cam.

Rob has built some SM 680R's that take it further--including some fancy solid film lubricants and porting work. Can the BRP make more than 60 hp and last for a race season? For sure!!

I'm drooling!...I want one!!!!

Bruce, Mikekay, I always hate to ask what someone spent on something so I'm not asking what you spent but what would a general price range be for someone who wanted a 680 set-up similar to ya'lls if they already had an uncorked STOCK motor with edelbrock carb? everything ... headwork, crank, machine-work, boring Carb, etc... I'm not serious enough now to call Rob and waste his time on my curiosities so I thought I'd ask you.

I look forward to hearing from you



well I had it figured to some point....what makes it hard is I took it in to have some gears fixed. That was covered under warrenty......I also bought a XR400 Edelbrock (still waiting for) If you take all that into consideration it somewhere around $2400 with labor I guess...some of the labor over lap and that is without the Edelbrock carburetors or trans work. I have the 11:1 wisco piston kit and sleeve with install, corrillo rod kit (XR600R bigger bearing) S/S valves (intake 3mm oversived) all the kibberwhite springs and stuff, cam chain, and cam this is what i paid for this part. It was the Edelbrock Dyno that was used. Have you used it? do you have dyno charts?

I'm sure your glad you did it...but are ther ANY downsides? maintaince...reliability...how about Dual-sport use?

Would you have done it earlier than you did looking back? or still wait until you needed the work to it anyway?

Sounds like so much fun!

The best thing about it....it's like having enough power to start off in second gear and have a sixth! It's just enough power where third pulls the front wheel off the gound more then second did and faster with stock 14/48! I put a new tire on with the 14/48 gearing to get ready for the Dyno run....I took off from a light and was heading down Beaumont ave. Hit third and got behind a truck doing about 40....I eased off to look to pass...all clear pulled the Oinkers ear to get going and almost looped it :cry: I dropped the front and looked over at the old man driving the truck as I got on it again...he was shaking his head...like I was some out of control kid. I wish I would have taken the time to have run the bike on the dyno each step of the way...new...all the stuff when new and now with the new engine. It looks like that it is a 12hp difference from uncorked to now. It has a more steddy increase in power to the top, best patr is going through the whoops if you need the power to straighten out the bike it's there.

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