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Discussion Starter · #1 ·
Hi all,

A year ago, I bought a fairly stock 2001 Honda XR650R, with the intentions of riding it on the street and taking it to the desert once in a while. In other words, use it as a dual sport. My buddy had the same bike so we went riding a few times together, which was a blast, since we could share each other's knowledge on the bikes. :thumbup:

Let's travel back in time...I discovered SM about 7 years ago, when a class mate of mine in University in The Netherlands (that's where I'm from) had a Husky with 17's. The first time I saw it, honestly I thought it looked ridiculous on a dirt bike since it made the bike look a lot smaller...If I even knew back then what I know now. :D
I did LOVE the thumper sound though!

So back to the XR...I read a bunch on the Internet about this bike, and discovered that it was a very good base to do an SM conversion. Yes, it's a pig, but a pig with some power up the a$$. :arsenal
I didn't think twice and sort of let the dual sport behind me and started doing the SM conversion. I bought Excel/Talon 17's, brakes, hand guards, some protectors here and there and voila...an SM was born. I never touched my suspension which was always bugging me, up to last week. When I finally tore down the forks and rear shock. I will have these revalved and reprung for my weight.

One big glitch in the whole conversion happened when I tried to adjust my chain slack...yes, one of the adjusters broke flush with the swingarm..Nice one... The other adjuster was frozen as well. The guy I bought it from must have never adjusted these. :headscrat:
I've been :bike: like that for the last year, although it wasn't very safe.

Last week I finally took off the swingarm when I took off the suspension parts as well...AND THAT'S WHEN IT STARTED! :eek:

Anybody heard of those 'while you're in there' projects? :lol:

I made the decision to tear down the whole bike and rebuild the whole thing, including powder coating the frame, swingarm, engine and other misc stuff.

I will use this topic to show my progress to you including pictures of course. Also, it helps to keep me going, although I'm having a blast doing it. I can't wait till it's done!!!

Feel free to give any advice on color scheme or other useful tips! I will probably be asking you all for advice on a lot of different things anyway.

This is how I bought the bike.


Here is it in SM trim and how I rode it for the last year.


The teardown begins...






An XR frame next to my buddy's VTX1800, what a size difference. He's just compensating... :rofl:


3 Afternoons and a six pack of Heinekens later...
 

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Discussion Starter · #3 ·
I'm planning doing minor engine work, probably only a Stage 1 cam. Then I might buy a pumper carb and make my own air intake system.

It'll be a beast, that's for sure!
 

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For riding on the street, go with a stage 2 cam, moves the power up in the rpm range, which is wear we ride!
 

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Discussion Starter · #5 ·
For riding on the street, go with a stage 2 cam, moves the power up in the rpm range, which is wear we ride!
Hmmm :hmmm:

Need to think about that one...I don't want to lose too much on the bottom end. Maybe I'm just thinking there is this HUGE dip in the power curve, but that in reality it's not nearly as bad.
 

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Hmmm :hmmm:

Need to think about that one...I don't want to lose too much on the bottom end. Maybe I'm just thinking there is this HUGE dip in the power curve, but that in reality it's not nearly as bad.
It dosn't lose power, just moves the peak power up. The bike will pull up to the rev limiter. If you put in a 1 point higher piston, you will keep all the bottom end and gain some. High lift cams drop compression due to intake valve overlap, which you might feel in low end hit. But they pull in a lot more air to burn at high rpms, which adds peak hp. The added compression from a high comp piston, builds back the compression loss, and keep the low end torque. If you do get a piston, buy a JE forged. Another thing to do is a good header system. I have a Big Gun full system, but I don't know what is the best system out now. I do know that I gained a LOT of power with the bigger head pipes.
 

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if you're digging into the motor to put a piston in to match a cam for high RPM, put in a good con-rod, as well.
 

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if you're digging into the motor to put a piston in to match a cam for high RPM, put in a good con-rod, as well.
Good call! I have a Falicon rod, but a Carrillo rod would be good too!
 

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if you're digging into the motor to put a piston in to match a cam for high RPM, put in a good con-rod, as well.
+10.

The only thing that will kill these engines is sustained high RPMs.

Make sure you replace the timing chain and tensioner while you're

in there. When I get around to building mine (I'm not gonna bother till something breaks)

I'm going for LOTS or bottom end torque. Mine will only go to the track once or

twice a year, so I want instant hit on the bottom for the street. Plus, me and the

guys I ride with get in the dirt a lot (with 17s), I like being able to run

tall gearing, and still have the ability to lug it off road.

I've read posts by a lot of people on ADV rider that built their XRs for

top end. They regretted it when they found they had lost that great

bottom end, which is what they needed in the woods and on the street.

When I "build" mine, I'm just going to put a stage 1 cam in, edelbrock carb and a more open exhaust.

my .02
 

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The big question here is, will this bike be used for the street, or the dirt? My bike has tons of low end hit, and way too much high end power to keep traction on dirt. I would never try to ride it on single track tight trails with the motor it has now. But after riding it with the current motor, I would never want the stock power that it had before the internal motor mods. I lost my motor due to lower rod failure last year trying to do a speed run, tried to pull 120, and was at 119 for about 12 miles. I had to build a motor, and am damn happy with the motor I built! I have a crf450x to ride off road.
 

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Discussion Starter · #11 ·
I'll be riding this bike 99% street, and I do like the large bottom end torque. Originally, I was planning on the EXACT same mods as Svmango described, so I'm really still undecided how far I want to take this project. I could spend $1000+ on engine work and still not be satisfied, knowing me...

Yes, I would LOVE to put in a:
Stage 2 cam $190
11:1 Piston, stock bore $180
Falicon rod $300
Cam chain + Tensioner $120
Misc gaskets $60

That totals to $850...But I do have an awesome engine then... :hmmm:
 

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what kind of power/torque differences can be had by working the internals with all that? because it sure sounds like a better spend 850 than on an exhaust
 

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Discussion Starter · #13 ·
From what I've read it's possible to get around 65 on the rear wheel with all these mods. :thumbup:

I dyno'd @ 47.83 hp and 42.40 ft-lbs on the rear wheel. Only mods I have are uncorked and a K&N replacement filter in the stock air box. I do not have my side panels cut. Reason for that is that the bike runs very nice with a very flat torque curve and I didn't want to mess things up.
Just for the heck of it we dyno'd without an air filter and hp went to 50.60 hp and torque to 43.65 ft-lbs, but there was a huge dip in the bottom end. Obviously that was with the current jetting.

But things might change soon...I just have never worked on the internals of an engine (as in piston, rod, etc.) so I feel like I should leave this to a pro...
 

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Keep us up to date on the build! I am in the process of my build. It is still a dirt bike for this summer, but after that...it's all street.

The guy I bought my bike from already had a 10.5 piston, stage 2 hotcam, port and polished head and pumper carb in the bike. I bought a Staintune exhaust and that should be about it for the engine. I will do a complete rewire this winter along with the precious wheel purchase (Woody's). Next spring it will be on!
 

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I'll be riding this bike 99% street, and I do like the large bottom end torque. Originally, I was planning on the EXACT same mods as Svmango described, so I'm really still undecided how far I want to take this project. I could spend $1000+ on engine work and still not be satisfied, knowing me...

Yes, I would LOVE to put in a:
Stage 2 cam $190
11:1 Piston, stock bore $180
Falicon rod $300
Cam chain + Tensioner $120
Misc gaskets $60

That totals to $850...But I do have an awesome engine then... :hmmm:
Let us know how the 11:1 piston is, im intested in bumping my compression, but im not sure how much:hmmm:

Keep us up to date on the build! I am in the process of my build. It is still a dirt bike for this summer, but after that...it's all street.

The guy I bought my bike from already had a 10.5 piston, stage 2 hotcam, port and polished head and pumper carb in the bike. I bought a Staintune exhaust and that should be about it for the engine. I will do a complete rewire this winter along with the precious wheel purchase (Woody's). Next spring it will be on!
What gas do you run in it, 93 should be fine for 10:5 right
 

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Discussion Starter · #19 ·
These are interesting reads:

http://borynack.com/XR650R/HorsePowerMods.htm
http://borynack.com/XR650R/dynocharts.htm

It looks like on conservative dynos, an uncorked XR650R gets 42-44whp. On these dynos, it seems pretty much impossible to get 60whp and stay reasonably reliable. His is a 680 with big cam, big carb and big exhaust and he is high 50s.
Interesting links. Thanks! I did read the 2nd one, but never saw the 1st one.
I really would like to stay reliable, so I'm not going to push it too far. I've been reading quite a bit especially on connecting rods and if I should replace them. Sure, it's nice to have a completely fresh engine, but I don't have a money tree either. It seems I can get away with the stock rod if I don't pin it on the freeway for miles and miles, which I don't do (I actually try to avoid freeways). That would save me $300+ right there.

So for now I'm thinking a High comp piston and stage 2 (or 1 ?!...sigh!) cam should do the job.
 

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I am scared of the stage 2 cam, lots of posts about losing bottom end power with it. I had a too big pilot jet in (needed 68s, had 70s in) and riding around with a huge loss of bottom end was depressing. I am putting a stage 1 cam in next week and hopefully dynoing before and after.
 
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