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Old 03-01-2015, 06:16 PM   #1
aklein318 OP
Joined: Nov 2014
Oddometer: 47
Another XR400r build ---------PIC HEAVY------

So I had started with a KLX300, AFTER riding it a bit, I realize that was a terrible choice. Then, I realize the motor is a ticking time bomb, and a rebuild x2 ensues. (See KLX300 CARNAGE thread)

So I sell the KLX, and then this-

I was torn between an xr4, and a 650l. I like the idea of a 650l because I could hop on, ride to Arkansas, ride trails all weekend, and ride home. Well... Kinda.

I like the xr4 because of the weight, power, looks, and the abundance of cheap aftermarket goodies. Some may argue the aftermarket for the 650l is just as good, but I say they're wrong. If you're one of those, say so, and I'll prove you wrong. .

So the question rises- what about the road manners? Well the xr400 can have them with the right combination of gearing, and motor. How much lighter, and better handling can you make a 650l? Idk but I know the xr4 in stock form is great for trails, fire roads, and logging roads.

I looked at what the majority of riding would be for me.It will be exploring the VAST network of county roads, (most dirt) and trails that stretches all over Henderson county, and literally starts (for me) across the street. If I wanna take a trip to Arkansas and go exploring, the bike (be it an xr4, or an xrl) is going in the bed of my pickup, until I at least get to a motel, and what I'll describe as the center of the web of trails/roads to explore. I'm not gonna ride a dortbike all the way there, 650l or not. So.... Xr4 it is.

I've been searching for both for some time. Found some great deals, some insane deals, and also some head-scratchers. Why got me psyched about an XR was this one xr4 a dude brought to my shop for me to fix. The exchange went like this (in a nutshell)- (M-me/H-him)
M- Cool bike, what's wrong with it?
H- It won't start, I'm pretty sure its the carb
M- Okay, I'll check it out
(Testing, no spark, troubleshoot, bad coil)
M- Hey bro, your coil is bad
H- How much is it?
M- $30 for the coil, $20 to install
H- OK, I'll just come get it
(2 weeks later on phone)
H- Man you sure its not the carb
M- Yes, its the coil, I tested it per the clymer book
H- Okay

So today (like 2 weeks ago) I see it on craigslist for $1000. Still won't start. The new owner is at a loss, and just wants as much money back out of it as he can get. So I call him. He explains it doesn't have a spark, he bought it from a guy that couldn't figure it out. The guy replaced the stator, cdi, and put an XRs only mikuni pumper carb on it. I said okay... I'll come get it. (Already sold the KLX for 1500) go over, pay the guy a grand, he loads it up, and boom. I'm the proud owner of a Honda Xr400r, pumper carb and all. The carb has 0 run time, and isn't even installed correctly. Funny thing... The bike STILL DOESNT HAVE A NEW COIL ON IT. Its a 40 Honda part, 20 on eBay. Instead its got $400 in electronics, and $400 in brand new pumper carb. I bought the rest of the bike for 200. Lol

Build thread starting immediately following this important announcement.

aklein318 screwed with this post 03-08-2015 at 08:31 AM
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Old 03-01-2015, 06:19 PM   #2
aklein318 OP
Joined: Nov 2014
Oddometer: 47
Xr400r build------pic heavy-------

So I got a new coil, and I also got the new plug boot, as I understand they commonly have faults. Something about a built in resistor. Anyways I get home, and tear into the thing. Lots of well done krylon, but still... Its krylon. I'm more of a powder coat kind of guy myself, mainly because I've got a PC gun and a dedicated oven.

Little further digging reveals some DIY BS wiring. Little further... It has no air filter. And no auto decompression cable or lever. And Tue subframe is cracked... But... Its got a brand new pumper carb.

Anyways the goal is a street legal, bulletproof trail monster. Its gonna need provisions for DC wiring, and a battery (small ballistic). I'm picky about wiring, so I'm gonna build a new harness. The fact that its missing an air filter worries me. I don't like the silver krylon on the graphite metallic frame.

Folks... I'm tearing her down!

aklein318 screwed with this post 03-06-2015 at 05:55 AM
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Old 03-01-2015, 06:21 PM   #3
aklein318 OP
Joined: Nov 2014
Oddometer: 47
This bike at some point was attacked by a can of silver krylon. One of the better krylon job I've seen, but still crap. Anyways, I needed to rebuildy bike stand too. Apparently 3" Sheetrock screws are not quite enough for the design I've got. The next series of pics are just of over spray, preceded by my new bike stand.

Anyways, y'all get the point. So I checked the CS splines. Perfect shape

Take the intake boot off and find this. There's a lot of crud inside where the o-ring sits on the face on the intake port from PO not thinking a $7 air filter was important.

And them this.... Exactly how i found it. SAE bolts and all. Lol

Anyways, I get this thing down to frame, swingarm, and motor.... If I can't get that **** swingarm pivot bolt out, then I'm kind of up the creek in regards to changing swing arm bearings, and properly painting the frame. I HATE using the BFH (big f****** hammer) method to get a bolt free, but sometimes you gotta do what is necessary.

Anyways- you can also see where the silver krylon stops, and the regular frame paint starts in places. Looks crappy

Eureaka!!!! I used an 18" 1/4 extension and let's that swing a pivot bolt have it.... But not before applying a liberal amount of PB blaster. Actually, it shot right out. Haha

Tomorrow's journey. The PLAN is to get the misses in the shop and see what she's made of. Supposed to be gorgeous tomorrow, so keep yalls fingers crossed. Haha.

Yeah, and I've got parts everywhere, but I keep it moderately organized.

Okay, so basically what I'm gonna do, once I get the frame painted, and the subby beefed up and painted, in gonna basically move down the line. "Okay, today I'm working on the..... Triple clamps". Clean them up, polish or sand blast, whatever I decide to do, on to the finished parts shelf. Next day- "okay today I'm working on the.... Forks"... Take them apart, clean em up, change fork seals and oil, installed new springs, etc, put them on the finished parts shelf.

I'm very effective when I work like this. Once the 'needs work' shelf is empty, and the 'finished parts shelf is full, I put it all back together. Sometimes I'll finish a part and install rather than putting it on the shelf... Just depends. Each part will likely be a separate post.
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Old 03-01-2015, 06:24 PM   #4
aklein318 OP
Joined: Nov 2014
Oddometer: 47
OK, so SOME progress, but not much. Twas important though. I built a table for the rebuild, took my 18 month old to this discovery science place where kids enteract with sciency stuff. She loves it. I had a customer call me up, with a YFZ450 that wouldn't start. Problem is, he's got someone driving 10 hours through the night to buy it tomorrow morning.

Not ordinarily the question "why would someone drive that far for an ATV... THIS IS NO ORDINARY ATV. Its like a 510 stroker, with a 14.1:1 CP piston, and rod. Balanced, welded crank, Ferrea 5 angle valves mated to copper-berrilyum seats and some REALLY nice porting. Big cams, expensive titanium springs and retainers, and about 3 grand in suspension. Also... It has trail tech lights... Running off the AC electrical system... Put together with like 20 small pieces of 16ga wire hap-hazzardly spliced together, with ZERO insulation at the splices. It was obviously put there by a drunk child with ADD.

ANYWAYS, it was grounding the AC system. Everything works now, save for the bulb that blew in the fiasco.

Pics or GTFO, right?

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Old 03-01-2015, 06:26 PM   #5
aklein318 OP
Joined: Nov 2014
Oddometer: 47
I haven't checked piston availability for these, but I know I want to use cast pistons due to their lighter weight, and thermal stability. (Pro-x or Namura) I like the idea of running a tighter piston bore clearance. The current bore is spot-on 85mm, at to top of the bore. I'll probably go .020" over, if available. Forged pistons have their place, but a low compression xr400 isn't really it, IMHO.

Next up, is painting the frame. I used a sctoch brite pad to get all the dirt and grime off, but only after power washing it thoroughly. After a dry sctoch brite pad, I used a wet one, doused in acetone. I made sure not to get through the factory powder coat. It IS in fact the best primer if prepped correctly. After that, I applied two light coats of Bull Dog adhesion promoter. Guys, this stuff is awesome. If you prep motorcycle plastics, and get the surface evenly roughed up, you can apply this stuff, then regular 2-part (chemically hardened/ catalyst) base coat paint with a flex additive in it, and it lasts for a long time. I recommend this product to anyone.

I used Duplicolor Perfect Match aerosol enamel, in Toyota Graphite metallic. This paint is also a very good product. Flows out well, and applies really evenly, with great coverage. Also its available at every major auto parts chain store. After this I'll finish it with a product called SprayMax 2k clear. Its a catalyst clear that's impervious to gas and any other kind of chemical a xr400 can spew on it. Basically the same stuff as automotive clear. It has an internal chamber with the catalyst Gardner that you "activate" prior to use. After it is activated, the clock is ticking. In 45 minutes, it'll be hardened inside the aerosol can. The catch is, you gotta let the enamel base coat dry for a few days. Enamel paint shrinks as it dries, and really takes about 3-5 days (depending on weather) for this process to be complete. Prior to clear, I'll go over it with wet 1200 sand paper. Pics are respective to the text above

All of this torn up metal was in the pick up screen. There was actually a little but more too.

My messy table. I've never worked from one of these before, but I love it. Normally o work off my 36" high work bench. It gets crowded quickly

Very carefully masked off the Vin, and manufacturers tag. It thinks these are the little touches that make the nice bikes really stand out. (I obliterated the Vin stamp. I don't like the idea of the VIN being out for the world to see)
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Old 03-01-2015, 06:29 PM   #6
aklein318 OP
Joined: Nov 2014
Oddometer: 47
Okay, so I knew it had a new stator... I didn't know whether or nownit was an aftermarket, ornfactory, and what kind of output it had. Someone please correct me if I'm wrong here, but didn't the factory unit only have like 4 poles wound??? Anyways, I PRETTY sure I've got a 200w stator here. I'm not sure, and could REALLY use some insight from those of you that have toiled with aftermarket stators. I'm not sure how exactly they had it wired, but I know there are two yellow, and two white, in addition to the pick up circuit, and the other two that have like, black tube connectors.


I'm now aware this is an electrosport stator, with 2- 100w floated circuits
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Old 03-01-2015, 06:39 PM   #7
aklein318 OP
Joined: Nov 2014
Oddometer: 47
Anyways, I was fiddling around in the shop. I was going to order my piston kit, but instead spent $100 on my "deductible" for a new replacement phone. (What a friggin scam ol Samir, and Hajda have going with that. Pay $9 a month, then $100 for your deductible on your phone insurance, then... When its all said and done, they send you a rebuilt POS some frat boy threw up on and washed off in the toilet)

Anyways, I went out, and decided to start the process in the order the parts should go back on the bike. First up was the swingarm. I need a new slider, and guides.

Next up was the triple clamps. I polished the lower, and will powder coat the upper. I'm sure some of you may be asking, "why not the same on both?" The answer is simple- because I wanna....

Actually the lower is a smooth part, with zero prep for polishing, whereas the upper is a sand cast part, and would require hours of sanding to smooth out all the millions of little dimples. Thing looks like Rosanne's ass. Lots of little dimples. Haha

Anyways, hope you all enjoy.

Also.... I'm wanting ideas on color schemes for this scooter. I'm kinda leaning towards black/white, hints or red, or some variation of the such

Also.... I gotta buy a new front rim. Where's the CHEAPEST place t get them? I wanna hear it all... From the dangerous Chinese ones, to the screaming deal on excels.

aklein318 screwed with this post 03-08-2015 at 08:47 AM
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Old 03-01-2015, 06:42 PM   #8
aklein318 OP
Joined: Nov 2014
Oddometer: 47
Got the swing arm and shock linkage greased up, changed 2 bearings, greased err thing, and put back in the bike. I know the swingarm pivot bolt will have to come out to put the motor back in, but well cross that bridge when we get there. Top clamp is powdercoated, rear brakes cleaned up and reinstalled. Anyways, PICS!

Hur dey iz

What do y'all think about polishing the shock resivor??? Cool, or over-doing it?
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Old 03-01-2015, 06:45 PM   #9
aklein318 OP
Joined: Nov 2014
Oddometer: 47
Fork seal HOW-TO

So I was looking at my unfinished parts shelf, and decided I'd call Honda and see if they had any fork seals in stock. Luckily they had them . I went and picked them up, plus some 10w fork oil, as I'm 200lbs, and ride fast.

The Honda manual give a process that will work, but honestly, there's a lot of redundant, useless steps, as well as a few tricks I'll show y'all.

Clamp your fork tubes in a vice, or if they're still in the bike, loosen the fork caps. If you're using a vice, use wood blocks, special for tube holders, or... an old T-shirt. Back your rebound dampner screw out all the way. Take note of how many clicks it was so you can set it back when you're done.

Now dump all that nasty old oil out. Work the fork in and out to get the oil out of the cartridge too. When you're doing this, you'll understand what I mean. Easy concept. Anyways, not very much came out of mine, which is why they felt like dollar store pogo-sticks.

Ewww- there's supposed to be like 873 ml in there.

Now, take a 14mm wrench and hold the stop nut so you can remove the cap from the plunger rod.

Okay now set the cap aside. And put the fork back in the vise. Clamp it at the top of the fork tube (the bottom part of the fork) so that you've got it clamped abut in the middle of the whole assembly. Push the fork LEG (chrome part) all the way in. Now, with one hand put pressure on the fork spring. The idea is to put pressure on the lower part of the cartridge so it doesn't spin when you loosen the 'center nut', which is the nut at the bottom of the fork, with the compression dampner screw in the middle. With your other hand, back out the 19mm center but with an IMPACT. If you don't have an impact, be it pneumatic, or battery operated, turn your man-card in, and go have some jasmine tea. If the nut spins, but doesn't back out, apply more pressure to the spring, you wuss.

Okay now that that's loose, remove the spring, and take out the cartridge, and dampner rod. Its 2 parts, but they come out together.

Next up you pry the dust seal out with a flat head screwdriver. Super easy, just don't get rough and mess stiff up and scratch things. Next take out the wire snap ring thing that holds the fork seal in. Identify the end of it, and pry it up with a skinny flathead, or pick.

The red line is the cartridge, the green line kinda points to the snap ring.

Pull it out

Okay now this is gonna sound strange, but... Its the way you do it. Hold the fork with the leg (chrome part) in one hand, and the fork tube in the other. Slide the leg till you hear a *clink*. That's the lower bushing, hitting the upper. Now give it ****. Tug, tug, tug till it comes out. You'll get the upper, and lower bushings, a washer, and the fork seal all at once.

I didn't get a picture, and now I'm kicking myself. Anyways, there's still an aluminum tube looking piece down in the bottom of the fork tube. Dump it out, clean it up, clean EVERYTHING up, and get yourself ready.

Next thing. Put the new (if they need it) bushings on the fork leg, just like the old ones came off. Slide the washer on, and slide the greased up fork seal onto the fork leg. The side with the spring goes downward, the writing faces up.

Now, take the aluminum spacer thing and put it back down in the fork tube. When its all put together, it fits into the bottom of the fork LEG like this, but for now, just put it down the fork TUBE, flange side down. In this pic you can also see both bushings. The blower one sits in a groove on the fork leg, the upper is just sliding free at this point

Drop that sucker on in

When its all said and done, the bottom of the cartridge fits into the little aluminum sleeve you just 'deep-sixed'

Now, put the fork leg into the fork tube. Its not gonna go all the way down at first because nothing is there to hold that little aluminum sleeve in place we just dropped down the fork tube. It'll be like this- (see pic) use your finger to center it, and slide the fork leg over it. Gotta jamk it around some, but its easy

When its done, and in the correct spot, it looks like this- centered, fork leg all the way down, and you can't really see it.

Okay so the lower bushing is at the bottom of the fork tube attached to the bottom of the fork leg. The upper bushing is at the top and you gotta press it into the fork tube. Use the washer between the seal and the bushing to kinda provide a flat surface to jimmy the bushing down into its spot. You don't necessarily have to get it worked all the way down. It'll go to its home when you drive the fork seal in. Slide the fork seal down the fork leg, and get it lined up to drive in. Younjeed to use a fork seal driver for this part, but I don't. I use the flat side of a body hammer with gorilla tape wrapped around it, and a rubber mallet to do the driving. Sharp form blown to one side, and then to the other.

Folks, I really don't recommend this method. Its a good way to mess up a fork seal and have to do this all over again. Practice makes perfect with this method, and I've got a bit. Anyways you'll know the fork seal is all the way seated when you can see the groove for the retainer clip. Put the retainer clip in. Slide the dust seal on. Tap it into place.

At this point you'll have this.

Slide the cartridge into the fork leg. The fork leg should still be all the way down in the fork tube, and still centered around that aluminum sleeve, remember? Okay, the cartridge fits INTO that sleeve. Now, slide the spring back in and apply pressure so you can reinstall the center nut at the bottom of the fort the same way you took it out. With an impact... that you already have... Because youre a man, man.

Take the spring back out and get ready to fill with fluid. There are many ways to skin this cat, and everyone sets this up differently.

Okay, fork leg compressed, no spring, pour about 873 ml into the fork tube, but you won't be able to get it all in the first shot. Reach down and grab the plunger rod up and down. After a while of that you'll see the oil level drop. That because the cartridge is filling up. When you pull up on the rod, and fluid comes out the top, the cartridge is full. Get the rest of approx 873 ml in. Listen the exact amount isn't important, but what IS, is that both forks have the same amount. You need to fill it to about 100-120mm from the top of the fork leg. About 4 inches.

Now this part is where the manual gets stupid. I'm not sure what it says exactly, because I stopped reading.

Reach in with your little fingers and SLOWLY pull the dampner rod up. Screw the cap onto the dampner rod (not all the way) and then screw the cap into the fork leg, again, not all the way. The idea is to keep the fluid from squirting all over the place. Now pull up on the fork leg, and fully extend the fork. Remove the cap back off from the leg, and rod. Slide the fork leg back down a few inches, but keep the dampner rod all the way up. Put your spring back in and set the retainer on top the spring. Screw the dampner rod back into the cap and tighten it up. Slide the fork leg back up and screw the cap back into it.

Be carful the o-ring on the cap is in place. It'll try to booger out as you tighten the cap back on.

Tighten them up (it really doesn't take a whole heck of a lot of torque guys) install on bike. Have beer. Spend an hour telling everyone on TWTex how you did it.

Sorry for the typos
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Old 03-02-2015, 11:32 AM   #10
aklein318 OP
Joined: Nov 2014
Oddometer: 47
Does anyone know if the 400ex stator cover, starter assembly, and flywheel bolt directly up. Tue cases on the xr400 look like they have the cast bosses for the starter motor bolts, but need to be drilled and tapped. Any idears?
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Old 03-02-2015, 12:09 PM   #11
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Originally Posted by aklein318 View Post
Does anyone know if the 400ex stator cover, starter assembly, and flywheel bolt directly up. Tue cases on the xr400 look like they have the cast bosses for the starter motor bolts, but need to be drilled and tapped. Any idears?

Almost: you need the TRX crank as well. The flywheel mount sticks out a little further to make room for the starter gear. There was an extension made that allowed you use the XR crank, I have no idea if it's still available or any good.
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Old 03-02-2015, 03:37 PM   #12
aklein318 OP
Joined: Nov 2014
Oddometer: 47
It'd be a cool idea if its not janky. If I wasn't planning a new top end, and wheels, a whole bottom end off eBay. There's one with a 3mil stroker crank right now for $500. Complete bottom end. Figure I can pull the crank, clean up the rest and sell it back on eBay, but I'm just not sure. Thanks for the info!
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Old 03-02-2015, 06:17 PM   #13
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ahhh. can you do that to mine?
Riff Raff 2015!
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Old 03-04-2015, 05:47 PM   #14
aklein318 OP
Joined: Nov 2014
Oddometer: 47
So big day today. I got my cabinet put together yesterday. I honestly dont see how they're making any money off these things. I mean, it takes like $40 in hardware just to hold this thing together. Lol. This pic was while in progress, I'll get an updated one tomorrow.

Then I did one of the cases for the BrokeForce 750... Just to see what soda would do to it. Soda blasting is not very abrasive, and pretty much water soluable, it doesn't hurt gasket surfaces, or fragile components, or seals. Basically it just barely cleans muck off of whatever substrate its adhered itself to. I'm not powdercoating these, just paint, so this should be suitable.

Then it was time for my cylinder head. Blasted the combustion chamber with the valves in. Removed the valves, and blasted the ports.

This exposed some of the nastiest casting flaws I've seen. Mother of god. I didn't get a friggin picture of the casting flaws in the intake, for a bef/aft comparo, but I did get one of Tue exhaust, which wasn't nearly as bad as the intake.

I'm doing a light blueprint port job on this head. Basically removing flaws, and smoothing everything out. Not gonna remove very much material, and plan on staying away from the bowls for the most part. The exhaust will be mirror polished to prevent carbon buildup. The bowls will be marginal.

Another problem area is the transition past the bottom edge of the valve seats. Honda did a terrible job there too. So far, I've only done the intake port. More tomorrow.

Enjoy the cylinder head porn ;-)

I spent a lot of time on the port divider as it was very asymmetrical. This creates pressure differences and uneven fuel disbursement both in the intake plenums, which translates into the combustion chamber. Again, I friggin FAILED miserably taking before pics, but there was a rough flaw right in the smack middle of the divider, as well as a weird hump/bump on the floor of the left side. All pretty now. (I am by no means a professional at porting, and I'm sure that shows. I DO understand many of principles that apply to create good flow characteristics, and how to apply them.)
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Old 03-05-2015, 06:32 AM   #15
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I dunno, but I think your porting looks pretty good. I've seen pros do a worse job.
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