xr660/hrc cam/port+polish/khein41pumper

I have a 96' Xr600 with a thumper racing 660 kit. The head is ported and polished, HRC cam, uni high flow filter and FMF power coreIV exhaust. I want to know how the khein 41mm fcr flat slide pumper carb would work with these mods? And does anyone know of any deals on this carb?

Mr660, if you were smart, you would trade in that boat anchor and buy a Yamaha 426. You will save 30 pounds and have almost as much horsepower! Hee! Hee!

Disappointed with you HONDA folks! I at least expected someone to have a comeback for me backing up Mr660 (a fellow Honda rider). Most of you must either be asleep OR YOU AGREE WITH ME !!! "If you are afraid, just say you're afraid"

damnMIT Eagle!!! What the hell is wrong with you?!!! Sorry, just trying to liven the place up a little. :D Any ways, my argument is that the "uncorked" version of the XR650 has 55 hp. That is, well, a tad more than a YZ426. That is only removing stuff that stuffs it up too. Add cams, exhaust, air filter.... :)

Hey eagle426,

Kiss my ass!! all that extra 30lbs is going to do is leave that much bigger of a dent in your WR426 if I ever see you!! you knuckle head common sence tells you that nothing competes with displacement. if you had any math skills you would see that (660-426=234!!) Watch your back there is a 660 thumper watching!

First of all, I want to thank you DR. Zaius, you totally made my week. I am still laughing about your reply! Second, Mr660, my math skills are great. Unlike you who more than likely had to use scratch paper to figure out the displacement difference. Then again, I suppose that you could have counted by 10's on your fingers and toes. If you want serious math, here you go! Supposedly, you lose 1 horepower for every 6 pounds. Considering I do not see very many XR600 riders with a small body structure, I estimate you to be about 350 pounds. Therefore, calculating in your weight plus the extra 30 pounds for the bike, YOU ARE RIDING THE EQUIVALENT OF A 5hp BRIGGS AND STRATTON LAWN TRACTOR !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


In all fairness to the lawn mower, at least they can be made competitive


Eagle, common now! :D That was just a low blow! 350lbs. That's funny. :)

Mr660 just asked for some advice on his bike, which is TT's main focus. Eagle, you had nothing of use to add, so why come over? The rock hard reliability??? The fact that the XR600R is the most reliable bike ever made??? Then go ahead and say so, but there is no need to attack other members.


Team TT Moderator :)


I guess since you are going to be the hall monitor, I WILL LET THE TRUTH BE KNOWN! Before anyone else starts crying and takes their ball to go home, you should know that Mr660 is my brother! He is in Ohio and I am here in North Carolina, therefore this was a good opportunity to have a little fun. I may have temporarily earned the "cyber-prick" title, but the main point was to make some smiles. I believe I acomplished that with DR.Z and fastkevin, at least they did with me. Otherwise I would not have entered "someone"elses forum to stir up sh*t. Secondly, Mr660 and I have discussed his topic on the telephone, and I have been watching to see what USEFUL information he was given. Not a whole lot = time to jag wires! Once again, I send out a thanks to DR.Z and fastkevin!

Also, I apologize if I made anyone lose any sleep over this! Plus, feel free to come bust my balls if you see me post anywhere. SARCASM IS A WAY OF LIFE!

WAY TO GO KNUCKLE HEAD!!(eagle 426) The scorching reply's crack me up! Any body feel free to let them rip! It's all fun and games untill someone gets ran over by an xr660! (soon enough eagle!) Along with the scorching i would like some input on the khein fcr 41mm pumper carb on the 600's

You should contact Sudco (maybe-sudco.com)

They're usually pretty good with this kind of info. Another would be XR's only in Hesperia Ca. They have a website too.

Thanks kevin i will look them up!

Mr. 660. All that money you are investing in that Ole' Bulldozer you could have something better. Putting all those new parts on it you still have something that needs to be put in the Smithsonian. If you like I can get a tow rope and pull you at the same speed as Eagle..So you can see the side of that sweet 426 machine instead of eating his roost. Let me know if you would like the help.

Oh goody! another wise ass, mouthy wr426 rider. As you already know you do have a weight advantage over me. You are more than welcome to put your WR in front of the OLD XR and hook a rope to it.(sort of like chaining yourself to a pissed off lion!) You may start to pull the OLD BULLDOZER after burning your clutch out from slipping it to get me moving, but once you get me moving I will let the old clutch out, jump start the beast and then you will feel the weight of the smithsonian master peice on top of you and your WR 426. As I pointed out to Eagle 426 displacement rules (660-426=234cc)

[ March 27, 2002: Message edited by: mr660 ]

Mr660, does porting and polishing make a big diff in how the 600 runs? How much does it cost? Is it worth it?


There is a obvious difference at the top end. I have the HRC cam which has a greater duration than stock, which means that it is holding the valves open longer, which means more fuel and more air moving. The trick with porting and polishing is a ported intake with a mild stone(approx 80grit) to help with bottom end and on the exhaust port use a smoother stone(approx 120+grit). The rougher intake helps to break up the incoming air and gas mix to give a better bottom end and the polished exhaust allows the combusted gases to flow out of the engine more freely. The porting and polishing is great for high RPM's but doesn't do much for the bottom end power. My combo of the cam and the porting and polishing makes my bike sing like a bat out of hell at top RPM's. Shop around for prices on doing the porting and polishing: Thumper racing 200.00 did mine, check your local performance/machine shops, XR's only, look in the back of any dirk bike or dirt rider magazine they will have alot of leads or even check your local library on do-it-yourself porting and polishing.

Good luck!

Hey Mr. 660 . Displacement is one thing. But think about this for every 6 pounds it is equivalent to loosing 1hp. So based on the weight of the bike and the rider. So based on the numbers I would buy some more parts to make it more displaced. I know someone that has a mini bike for sale that might be alittle faster.

okay ncwr426, not a bad idea buying up the mini bike for sale. I think I will use it for starting my massive displaced engine. Considering that you and Eagle426 can't even kick start the beast. My wife has grown bored with her XR200, now she's askin' for a wr426. Since I don't want her riding something with too much balls, I think I might consider it. Once again losers, DISPLACEMENT RULES !!!!!!!! (660-426=234)

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now