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Edelbrock Carb! Edelbrock Carb! Edelbrock Carb!


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I have one bored over from a 36mm X 42mm (stock Edelbrock) to a 40mm X 42mm bore on my XR680R. I have a Edelbrock 32mm X 38mm (Stock for XR400, Stock Kehin is 36mm) Bored to a 38mm for my XR400. The XR400 rips! What a difference! ? Both bored over carburetors give more horsepower and more torque over what they were from Edelbrock but, both are not stock setup bikes. The XR400 is a stock engine with Big Gun Race Series Exhaust System and Uni air filter. The Xr680 is ? I think it's the second best Modification you can do to these bikes! The first is Suspension. (Un-Corking goes without saying!)

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Before you open it up to 40mm, you may want to make sure it will still give you good response and make as much power by veriying this with someone whose done it or built your combo. Opening it up allows more volume, but it also slows down the velocity, which will affect performance to some degree.

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i'm sold!

when i finally, hopefully around april, step up to a 650r i'm throwing one on.

Its the most frustrating thing in a race to drop your bike for just a sec. and it dies. 3 minutes and 40 kicks later up and running again but man what a waste of energy!

all that said my old 91 is still a kick arse bike, just race prepped for Sun, 95 miles. gonna be a cruise for the old pig. wish me luck with out the edelbrock....

later

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I have had many problems sense I went to a pumper Carburetor on my XR650R. It's been the same problems with both the Mikuni TM40 and the Edelbrock. I can't find the hesitation off idle when I wack the throttle coming out of a wash or corner. The bikes front tire climbs up all the time. I go through rear tire much faster and front tires last a lot longer. I use more fuel but, my cheek mussels hurt all the time from the ear to ear grin. Don't get one it makes you want to ride more costing you more money! ?

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Got to be careful on an Edelbrock equipted 650, when you lay it down it will continue to run, and the oil system wont work too good with the bike on its side.

What I like about the Edelbrock, is no matter how much you've flooded it out, just give it 4 kick thrus with gas off and decompression lever pulled in, than turn on the gas, go to TDC, and give it a mighty kick while turning the throttle just like we did on the 2 strokes.

It will always start first kick with an explosive, ear-ringing rev, causing children to cry and Republicans to run for their lives.

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I have had many problems sense I went to a pumper Carburetor on my XR650R. It's been the same problems with both the Mikuni TM40 and the Edelbrock. I can't find the hesitation off idle when I wack the throttle coming out of a wash or corner. The bikes front tire climbs up all the time. I go through rear tire much faster and front tires last a lot longer. I use more fuel but, my cheek mussels hurt all the time from the ear to ear grin. Don't get one it makes you want to ride more costing you more money! ?

Kinda like the problems encountered with using synthetic oil.

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For those of us with stock XR650R's, except uncorking and protaper bars, what would be the best place to start modifying the BRP? And in what order first?

I have owned it since new in 01 and use my other bike, 01 CR250-selling and now a 03 Service Honda CR500AF, for MX style riding and jumping so I want the 650 to be plush in the dez and a little more response power wise. Plus it would be nice to be able to start it when I crash.

I am thinking:

1) suspension by either Precision Concepts, Baja Designs, or Barnums. 2) ? 3) ? ...

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My $.02 worth is:

In order of need.

#1 Un-Corking and greasing the swingarm and steering stem.

#2 Bars and controls

#3 Tires, and then more rear tires and then the next ride another rear tire ?

#4 Protection (Skid plate, rotor guard, Case Guard....ect)

#5 Suspension

#6 Larger Tank

#7 Power = Exhaust, holes in the side cover, Pumper carbuetor, HRC or 680cc kit.

#8 Chain X-ring and Ironman sprockets

Best Modifications!

#1 Suspension

#2 Pumper Carburation

#3 680cc kit (most fun! You need the other two to make it work)

#4 Bars

#5 Larger tank

#6 Exhaust

http://www.borynack.com/Bruce/XR650R/HorsePowerMods.htm

http://xr650r.borynack.com/

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damit y'all stop it!!

Somebody, quick tell me again how it's been problematic etc.. hurry. My wallet is starting to glow red!

?

Come on guys this in no fair for us poor guys that have to do other things like put kids througth school, buy things like food, etc.. Now the wife wants a new car to replace the junk van she is driving ? . I know all about the easier starting, no flooding etc but does it really make any difference in the way the thing runs? If someone gave you a started, properly jetted pig and you took it for a ride could you really tell the difference if you couldn't see the carb??? Be honest now since the wrong answer here may mean the oldest son's tuition payment may be late ?

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2~3 horsepower may not sound like much but, it's real "usable" "Feelable" "Grinnable" power if you are a full on, ride at the edge, WOT rider. If you are just a good trail rider that is not looking to kill yourself most mods are not that noticable. The way it comes on is the key though. No more easing into the throttle! Think about having all the power at once! Not avoiding the dead spot.

This does not need to be an "all hail Edelbrock" thread. You can get a TM 40 off ebay for about $200 and have a smoother pumper carbuetor then the Edelbrock. A Mikuni is a lot more time consumming to tune. I love mine (Mikuni) but, the bored out Edelbrock just was double the extra power. I gained 4hp holes in the side cover and the Mikuni. I gained 2 more with a bored out Edelbrock.

I think a good thing to know is most power gain is not stand alone. If you add a pumper you need to find a way to add more air in and out of the engine. Just holes in the air box, uni and a bigger header may only give you 1~2hp gain on a stock bike. Adding a Edelbrock to a stock bike would be a 1~2hp gain but, put them both together and you have a solid 4~5hp gain. So, my thoughts have always been modifications work together. To get the full 10hp gain from going to the 680cc piston I had to bore the Edelbrock and go to a bigger header. If you want more power you have to feed the engine more.

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Frog man, you did buy the bike before you heard of the Q.S. carb, am I not mistaken? I remember someone honking you off real bad who told you to sell the bike ? ! Anyhew, if you wanted to open the carb up, it wouldn't be done with a lathe. Remember the opening is elliptical, not round and it would be a mess trying to turn the carb. Anyone with a milling machine could hammer it out easily. ?

How easy is it to open the standard 36mm to 40? Can a somewhat skilled machinist do it on a lathe?
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