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docwyte
docwyte PowerDork
3/6/21 11:16 a.m.

In reply to Professor_Brap (Forum Supporter) :

I bought an extended fuel screw but found that the carb already had one installed.

made tuning the mixture a whole lot easier, thats for sure

docwyte
docwyte PowerDork
3/13/21 1:57 p.m.

Ok, time to replace the last maintenance item on the bike, the air filter.

Pop off the left side airbox cover, it's four 8mm bolts

That gets you to the airbox.  Pop off the hook and pull the bar away from the air filter, then pull the air filter off

New air filter vs old.  I'd say the old one is pretty dirty!

Pull the air filter over the plastic cone, then pop it over the intake, set the bar right into the middle of the plastic button on the air filter and place the hook back into place

Put the side cover back on and snug down the 8mm bolts.  Done!

I wanted to also swap out the front sprocket to a 16T from the current 15T but I ran outta time.  It looks like I'll either have to pop the master link off the chain or loosen the rear wheel and push it forward to get the chain slack to swap out the sprocket.  I might do that tomorrow, along with finally installing the right front brake setup

docwyte
docwyte PowerDork
4/2/21 4:37 p.m.

Finally got the 16T front sprocket installed, pulled off the 15T.  Much more work than I thought.  Initially I thought I wouldn't have to move the rear wheel.  Nope.  So then I pulled the rear axle (which is good cause the nut was on super tight, there was no way I'd would've busted that free on the trail) and pushed the wheel forward to get more room.

Nope, still not enough.  Luckily this has had its chain replaced, so I found the master link, popped off the clip and broke the chain completely free.

Off with the old...

In with the new.  I used a new nut and lock washer too. 

Then I got to set the chain tension, which was fun because some previous owner rounded over the bolt that holds the stop blocks on the right side of the bike.  That's just a M10x1.25x50 bolt though, so I'll go to the hardware store and buy another one.

I rode the bike today and changing out the air filter changed the mixture enough that I had to reset the fuel and idle screws again.  That was a bit of a PITA, but got it done after my ride, then banged around the neighborhood to make sure it was fine.  So far, so good.

Lastly a goodie package from Croatia showed up.  A brand new, in the bag, rear fender.  These are unobtanium and since the one on my bike has a crack in it I wanted one. Won't install it, but nice to have in my basement in case I need it.

docwyte
docwyte PowerDork
4/3/21 3:20 p.m.

Dealer had the bolts in stock!  So I rode over this morning to get them.  Still need to play with the fuel screw a little bit, it has a initial hesitation when you first tip into it from a stop.  Got the bolts, threw a leg over a new KTM 890 Adv R and a Husky 701 Long Range. 

Wow, that 701LR is sweet!  Really the modern iteration of my 640, just needs a fairing/windscreen, which multiple aftermarket companies make.  Much want!

Got home and played with the fuel screw, bike seems to be better on tip in, but does lightly pop from the exhaust on deceleration.  Hmm.

Also noticed my valve cover gasket is leaking.  Called the dealer to get the part, turns out there's no gasket at all, KTM used sealant.  Tech there recommended 3M-1207B, or HondaBond.  So I gotta get a tube of that stuff, but don't wanna pull the fuel tank off until the fuel level is lower.  Right now there's probably 7 gallons of fuel in it and I don't care to lift 50lbs off the bike...

docwyte
docwyte PowerDork
4/3/21 3:23 p.m.

Oh yeah, I test fit the 640 in my shed, which was the entire reason for buying a bigger shed!  Happy to say it fits.  Not a whole lotta space in there with the snow blower and lawn mower, but it fits.  Getting it in is sort of a PITA, I can't turn it tightly enough to get it up the ramp.  Luckily it's light enough that I can just lift up the back of it and turn it.  Getting it out is easy, roll it down the ramp and then right out the gate door.

Professor_Brap (Forum Supporter)
Professor_Brap (Forum Supporter) UltraDork
4/4/21 6:37 a.m.

In reply to docwyte :

Hondabond is my favorite. 

How does the plug look color wise? 

docwyte
docwyte PowerDork
4/4/21 9:15 a.m.

In reply to Professor_Brap (Forum Supporter) :

On a closer inspection it's the front, top rocker cover that's leaking.  So I went back to the dealer and got the gasket plus the cooper gaskets for the bolts.  I'll check the plug when I pull the tank to replace the gasket.  Apparently the head pipe bolt also goes into an oil passage and can leak, but there's oil above that header pipe, so I don't think it's that.  I'll go after the rocker cover first.

I'd really like to replace that chain adjuster bolt but I'm a little leery of trying to take it out.  I can get a socket on it but the bolt doesn't spin easily the way it should.  I'm concerned about rounding it over completely, or the bolt not coming out all the way, or it pulling the threads from the swing arm out.  I may punt on that one and give it to a shop...

docwyte
docwyte PowerDork
4/4/21 3:31 p.m.

Friend came over today (he used to own a 640) and helped me work on it.  First I replaced the front rocker cover gasket and cleaned all the oil/dirt off the front of the motor.  Tank back on, fired the bike up and no leak for now.  Hopefully it stays like that!

Then we reinstalled the right front brake setup that the previous owner removed.  Supposedly he removed them for weight, but he left the passenger foot pegs on.  Since I put the brakes on, maybe I'll remove the passenger foot pegs!  Always fun putting something back on that you didn't remove but I think we got it.  Bled the brakes, verified that they stop the front wheel.  Good to go!

Then I installed another piece of unobtanium.  Back in the day Stenhouse Racing made a bunch of cool parts for the 640, like a Scotts steering dampener mount, bar risers and an extended front axle nut.  That makes it easier to punch the front axle out.

Turns out his website is still up and the axle nuts showed in stock, so what the hell?  I ordered two.  A few days later I got a surprised email from him saying he'd thought he'd shut the website down.  Luckily he did have a few axle nuts left and he sent them to me.  Score!

Basically done with the bike with the exception of that chain tension bolt, which may be super easy, or maybe not.

My friend brought over his Yamaha T700 and let me ride it around the neighborhood.  Oh. My. God.  Wow.  That motor is silky smooth, seat height is good, bike doesn't feel very heavy and is flickable.  I may have to buy one that someone has farkled all out to replace the 640.

GCrites80s
GCrites80s HalfDork
4/4/21 7:50 p.m.
docwyte said:

Turns out his website is still up and the axle nuts showed in stock, so what the hell?  I ordered two.  A few days later I got a surprised email from him saying he'd thought he'd shut the website down.  Luckily he did have a few axle nuts left and he sent them to me.  Score!

Basically done with the bike with the exception of that chain tension bolt, which may be super easy, or maybe not.

 

Dude I shut a website down and it stayed up for five years. I figured I'd just stop paying the bill when my credit card expired and it would go away. Never got charged again after I stopped paying yet it stayed up.

mazdeuce - Seth
mazdeuce - Seth Mod Squad
4/5/21 6:07 a.m.

I'm surprised there was a 701LR on the floor, they're essentially all sold out nationally and they aren't making them or the big tank kits for 2021 and won't commit to doing it again. A bit of a hot commodity right now. 

docwyte
docwyte PowerDork
4/5/21 8:41 a.m.

In reply to mazdeuce - Seth :

Yeah, I know.  They're also no longer making the kit so you could turn a "regular" 701 into a LR.  I'm tempted to buy one just because of that but they're at least twice as expensive as what I could sell the 640 for, plus I'd want to add a rally fairing kit and, and, and.

I was very impressed with the Yamaha T700.  Very comfortable bike, super smooth motor, didn't feel all that powerful but I think the smoothness is hiding some of the grunt.

Unfortunately the previous owners ineptitude has popped up again.  Turns out he had the wheel on backwards.  No big deal , just remove the wheel, turn it around and Bob's your uncle, right?  Well, no, because the tire was mounted based on the wheel being on the wrong way.  So not only does the wheel need to come off, but the tire also needs to come off and get remounted, then I can put things back together the right way.  Argh!!  Luckily Performance Cycle mounts/balances tires for $20.  So I'll bring them the wheel and have them pop the tire off, remount/balance it and maybe even true the wheel up.

Then an eagle eyed viewer on the 640 FB group noticed I'd routed the brake line wrong.  I've got it wrapping around the front of the fork leg and it should be going to the back and not around the fork leg at all.  Ok, I'll own that, easy enough to fix, pop the line off the caliper, route it the correct way and then a quick bleed.

After that I need to decide if I want to tackle that chain tension bolt myself.  I'd love to shoot some penetrant in there but I don't think there's a hole in the swingarm for me to use...

docwyte
docwyte PowerDork
4/8/21 8:00 a.m.

So, no drain holes in the swing arm, however it's recommended that you add them.  So some quick work with a drill and a 1/8" bit later I've got drain holes.  That I've been shooting PB Blaster into liberally every night when I get home from work.  My tap showed up yesterday too.  So plan is to try and turn that chain adjust bolt out and if it comes out smoothly, I'll run the tap thru and put the new bolt in with a bunch of anti seize.  If the bolt is still turning poorly, I'll stop and take it to a shop.

In other news I'm somewhat vindicated on the brake line routing as I just copied what was on the other side of the forks.  Unfortunately that means I followed what the previous owner did, which was wrong.  So now I need to pop the lines out of both calipers to route them properly, then rebleed both lines.  Sigh...

adam525i (Forum Supporter)
adam525i (Forum Supporter) Dork
4/8/21 9:14 a.m.

In reply to docwyte :

Would a bit of heat on the aluminum swing arm help with getting that bolt moving? Not a torch but a heat gun to get it warm/hot to the touch and hopefully expand things a bit while you break it loose? Just a thought and there may be other concerns that make that a bad idea.

docwyte
docwyte PowerDork
4/8/21 10:23 a.m.

In reply to adam525i (Forum Supporter) :

The swing arm is a big chunk of metal, so a large heat sink.  Not sure trying to heat it up will make much of a difference.  Luckily the bolt isn't seized, it's just mostly stripped and doesn't want to turn easily.  I can get it to turn, it just feels sticky.  Hopefully the PB Blaster will let it turn more easily and I can spin it all the way out.  It's a 50mm length bolt and most of the bolt is threaded into the swing arm, of course...

docwyte
docwyte PowerDork
4/9/21 11:28 a.m.

This morning I was back at it on the 640.  First thing, take off the front wheel so I can take it to Performance Cycle and have them flip the tire to match the correct rotation of the wheel/rotors.

I'm currently waiting for them to finish so I can pick it up and reinstall it.  While that's happening I removed the rear wheel axle, crossed my fingers and toes and was able to remove that sticky chain adjuster bolt.  Ran a tap with anti seize through there a few times, look what came out!

Put anti seize on the new bolt and it went in like butter.  I decided I better do the same thing to the other side and was glad I did, I pulled basically the same amount of garbage out of those threads too.  Now both sides spin freely.

Lastly I decided I couldn't unsee the fact that the front brake lines are routed wrong.  Sigh.  Popped them off the calipers, routed them the correct way on the inside of the forks and got them back on.  I'll bleed them when I get the wheel in place.

Just heard from Performance Cycle, wheel is done.  So I should be able to pick it up, install it and bleed the  brakes and hopefully have this ready to ride.

docwyte
docwyte PowerDork
4/9/21 1:05 p.m.

Got the wheel back, put it on, made a bad choice and flipped the spacers around thinking that since I'd flipped the wheel around I needed to.  Then bled the brakes, which took forever.  Then noticed that I couldn't spin the front wheel.  Because it was hitting the left caliper because I had the spacers on backwards.  Sigh.  Wheel off, spacers on the correct sides, wheel back on.  Spin.  Yes!

Plan is to ride the bike around the neighborhood and make sure I've got the brakes bled properly, I fixed the oil leak from the front rocker cover and that I've dialed in the fuel screw.

Then hopefully the bike is ready for the season and I don't find any other things the previous owner messed up.

docwyte
docwyte PowerDork
4/9/21 4:17 p.m.

Rode it around, brakes feel great, bike is running well, no oil leak when I got home.  Looks like it's good to go. 

Will ride it for a month and decide if I want to keep it.  I bought it as a winter project and it may be time to move on...

docwyte
docwyte PowerDork
4/30/21 3:24 p.m.

It finally decided it wanted to be Spring, 75-80 today.  So I jumped on the 640 and met my friend with his T700 and we went for a twisty pavement ride up to Evergreen, grabbed some lunch and most twisties home.  At lunch I noticed that one of my eye glass lens had popped out of the frame, so I ran to the Oakley store on the way home to have that fixed.

The bike has a slight stumble when you first crack the throttle to pull away from a stop.  Time to play with the fuel screw a little bit more.  I turned it clockwise first, which I thought was the lean direction but the rpm's picked up and when I cracked the throttle it wanted to stumble more.  Ok, that's going too lean.  So I backed it off, then went another 1/3 turn rich.  Rode around the neighborhood stopping and starting.  Seems to be a lot better. 

I posted this in the 640 thread on ADV and the BST40 whisperer, Derek@MotoLab chimed in.  Seems like he wants me to change jetting, I need to call him...

I'll ride it to the base tomorrow and see how it does.  In other news, I've completely cured the oil leak, it was that front rocker cover.

NOHOME
NOHOME MegaDork
4/30/21 3:36 p.m.

Is there an Epic Ride Thread on the way or is this just in case?

docwyte
docwyte PowerDork
4/30/21 4:04 p.m.

In reply to NOHOME :

Doubt I'll have time to do an Epic Ride this summer, hopefully do some day trips and hit some passes with my friend.

Just talked with Derek@MotoLab, he wants me to reset the fuel screw idle setup and let him know what the actual end setting is.  I may need to change jetting based on that...

docwyte
docwyte PowerDork
5/8/21 10:25 a.m.

Ended up not riding to the base, had to carry a bunch of stuff that wouldn't fit on the bike.  Yesterday I finally dialed this thing in.  First I screwed the fuel screw in all the way to see where I was, which was 3+ turns out, way to rich!  Then I set it at 2.5 turns out and got it to run great at 1.75 turns out.  Really stable idle, no stumble when I give it throttle.  I was super happy.

Then I noticed that this hose had gotten burned through by the header pipe.  Gah!  Off comes the seat, headlight mask and fuel tank to get at this.  I also burned the F out of the tip of my finger on the header pipe.  More sacrifices to the KTM gods...

Shoot, this will have created a massive vacuum leak and thrown off my tuning!  Luckily I tried to blow through it and it was melted closed.  I popped another vacuum line on it and made sure it was well clear of the header pipe.

Since I had the fuel tank off I wanted to fix the cross over fuel hose.  The previous owner had left it really long and there wasn't a great way to route it that didn't put it close to the header pipes.  Not a good thing considering what it carries.  So I shortend the hose and made sure it was clear of the header pipes too.

Put the bike back together, crossed my fingers and fired it up.  Happily the tuning I'd just spent all that time on is still good.  Bike has a great, stable 1500 rpm idle, rides really well, no stumble off idle, pulls hard. 

Pretty much done with it, just wanna ride it on the passes around here now.

docwyte
docwyte PowerDork
5/15/21 1:13 p.m.

Rode the bike to work this past Thursday, it ran great.  However I noticed fuel dumping out of the carb overflow tube whenever it was running.  Ugh.

Double checked it yesterday afternoon, yup, drain screw is tight, fuel only runs out when its running.  Talked with Derek@Moto-Lab, could be a bad float, or float needle, or O ring on the float needle housing.  Sigh.  Instead of loading the parts cannon on this thing I decided to swallow my pride and pull the carb and just send it to him.  I did a few tests for him while I had him on the phone and verified I've got the float height set properly, so that's not it.

Another weird thing is I double checked my fuel screw setting and it wasn't at 1 3/4 like I thought but more like 2 3/4.  Which means I may need to put in a larger pilot jet.  Or there's some kookiness going on with my fuel screw as I noticed the shaft of the fuel screw was bent, after it leaves the carb.  Also didn't see the washer and O ring that should be there, but I assume they're inside the carb body.

Anyways, sent him the carb and fuel pump, that way he can hook them up and see what's happening and hopefully fix it for me.  I'm debating checking the valve clearances since I've got the bike blown apart right now...

docwyte
docwyte PowerDork
5/18/21 8:24 a.m.

Surprisingly UPS got the carb there yesterday, so even faster than they'd predicted.  Got a call at the end of the day from Moto-Lab, a new float, float seat and O rings seems to have fixed it.  I should have it back Thursday.  I'll check the valves, reinstall the carb, tune the fuel and idle screws (again!!) and hopefully be ready to ride

docwyte
docwyte PowerDork
5/21/21 12:02 p.m.

Have the bike prepped to check the valves.  Radiator fan off, decompression cable removed from the front rocker cover, vent hose from the front rocker cover removed, all the rocker cover bolts loose, I pulled the plug and found the TDC mark on the flywheel.

Friend is coming over later today to help me check the valves, I'll drop a straw down the spark plug hole to confirm I'm on TDC-C then check the valves.  Loose spec is .006, which is where I plan to set them as they tend to tighten up over time. 

Then reassembly, reinstall the carb, reset the fuel and idle screws and hopefully ride!

docwyte
docwyte PowerDork
5/21/21 6:10 p.m.

Confirmed TDC-C, did have to move it a bit.  Checked all the valves and luckily they're all in spec on the looser side, which is where I like them.  So new gaskets on the rocker covers and popped those back on, radiator fan back on, decompression cable on, ignitor on, new spark plug and plugged it in, carb in, hooked up the choke, throttle cables, fuel feed, filter.  Tank on, hooked up, choke on, turn the key, pray, thumb the starter.

She thumps to life happily.  Wait for her to warm up, set the idle at 1500rpm, play a little with the fuel screw but I'd pre-set it at 2 turns out and that's basically where I left it.

A quick ride around the neighborhood confirms she's running well.  Time to hit the trails!

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