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Old 07-23-2012, 07:38 PM   #1
gravityisnotmyfriend OP
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'94 KTM 620 EXC - shocks, carb and throttle

Quick background on me since I'm kinda new here. I'm a fairly large guy at 6'5" and 215lbs. I've been on motorcycles all my life - or at least since I was 5 years old. Got my first street bike ('79 CX500) when I was 16, started racing motocross when I was 18 on a CR250.

Currently, I have a '05 Sabre for long distance rides and a '71 CB350 for in town commuting.

Recently, I've got the adventure bug. I want to pound the T.W.A.T. I want to eventually tackle the T.A.T. I want to have a bike I can play with at the local ORV parks.

Well, I found this '94 KTM EXC 620. I took it for a ride. My first impression is that it is pretty much awesome. Ridiculous power. Great suspension. Brand new Pirelli tires that will lift the front end coming out of a gravel road corner in 3rd if you're not careful. .

Here's my only hesitation. KBB says it's worth $985 trade in or $1400 retail. The guy is asking $1700. I offered $1200, he said he'd take $1400.

What would my $1400 get me?

Pessimist:
An 18 year old bike with faded paint. No electric start and a kick starter on the wrong side that takes a manual to operate. A bike that vibrates significantly between 55 and 85 MPH.
Optimist:
A badass thumper that you have to work to keep the front wheel down under hard acceleration in the first three gears. An amazing DS at a 3rd the price of anything else on Craigslist.A brand new pair of $300 Pirelli's

What oh what should I do? All the bike really needs is for me to learn the black magic that is kick starting a 10.5:1 comp ratio single. It could use a paint job and taller bars. But that's piddly stuff for down the road.

I've got about about 20 hrs to decide. I told the guy I'd let him know when he got off work tomorrow. Any words of wisdom would be greatly appreciated!

gravityisnotmyfriend screwed with this post 01-21-2013 at 05:57 AM Reason: updated title
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Old 07-24-2012, 08:43 AM   #2
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Also - more specific questions.

Is the highway speed vibration anything to worry about? Is it normal for a 620 EXC or is it indicative of something mechanically wrong?

Will I get good enough at kickstarting this bike with practice? I plan on commuting to work on it and don't want to sit in the parking lot afterward looking like monkey humping a football.
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Old 07-24-2012, 09:14 AM   #3
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Quote:
Originally Posted by gravityisnotmyfriend View Post
Also - more specific questions.

Is the highway speed vibration anything to worry about? Is it normal for a 620 EXC or is it indicative of something mechanically wrong?

Will I get good enough at kickstarting this bike with practice? I plan on commuting to work on it and don't want to sit in the parking lot afterward looking like monkey humping a football.
Honestly I have only ridden ONE 620 and it lived up to its name KTM = Kick Thirty Minutes, miserable experience. With your price range will you find something "better" don't know, I'd keep looking.
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Old 07-24-2012, 11:13 AM   #4
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I appreciate your post, but you don't have any thing to say about it other than it started hard?

Really, the question I'm facing is whether or not I should spend more on a newer bike. I'm not buying something to go on a 20,000 mile epic trip - just something to play with on the local trails. Can I justify another $2000-$3000 for that? Or should I just buy this?

Sorry about the consistent bumping, but I gotta make a decision in a couple of hours.

Right now I'm leaning toward buying it. I don't know why I could just turn around a sell if I don't like (or find something better).
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Old 07-24-2012, 11:38 AM   #5
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If jetted correctly with either a Dell Orto or better still, a newer FCR carb, starting it should be easy. I had a kick only 620SX and it was a pussycat to start. You need to learn and follow the old 4t starting drill but once you know it there isn't really an issue. I don't recall what years had the Edlebrock but it is a POS.

For what you want it should be fine. I'd be looking for a newer RFS 400-520-525 for the typical $2000-2500 that was lighter and probably more likely to be reliable than an older LC-4. They can also be brought up to 07 spec pretty easily with some simple upgrades. I'd look for 2002 and newer EXC or MXCs, or a KTM 2t from 250-380 in that same era or even back to 1998ish. PDS and thinner body parts.
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Old 07-24-2012, 12:43 PM   #6
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I had a '96 RXC 620. Are you sure it's not an RXC? How many miles? The first thing I did was scrap the Edelbrock carb and put in a 39mm FCR. It made the bike really easy to start and it ran like a stripe assed ape. Don't worry about the left side kick, you'll get used to it. I'd check and see if the bearing on the trans mainshaft has been upgraded with the factory replacement, the originals had issues. The clutch is going to be noisy no matter what. Check to make sure everything electrical works. Does it have a title and has it been plated? If everything checks out OK, I would wave $1200.00 in cash in his face or walk away, he'll take it.
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Old 07-25-2012, 05:59 AM   #7
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It's a done deal. Called the guy last night and say that I just can't pay more than $1200 for an 18 year old bike. He said "Bring cash, I'll get the title".

Just over 6,000 miles on the bike. I drove it 30 miles home last night and drove it to work this morning. I'm liking it more with every mile.

Starting it doesn't seem like much of an issue. I killed it going through a little town on the way home, but she fired up on two kicks. This morning before work, it was stone cold and it took two kicks with full choke. So far so good.

I don't know for sure that it's not an RXC. The VIN starts with VBKRXL does that tell you anything?

What's the ole 4t starting drill? I'll search the site, but if anyone's got a link handy I'd appreciate it.
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Old 07-25-2012, 06:24 AM   #8
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Since no one answered this specific question and in case it matters to you at all now , the vibration is normal for the bike. That's why they were nick-named paint shakers.

Enjoy and post some pictures.
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Old 07-25-2012, 08:02 AM   #9
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yeah, I had read that they vibrate a bit. I found a really sweet spot at right around 70 MPH where the vibration pretty much goes away. Too bad that is really not useful on 55 speed limit roads! At 50, there's almost no vibration at all. But between 55 and 60 (where I normally drive) the vibration is pretty bad. So, I guess I just gotta go real slow, or stick to the interstate!


Pics? I snapped a couple last night when I got home. I'm 6'5" and this is bike doesn't actually look tiny under me!





I had to pull my other bikes out of the garage to rearrange and make a spot for the new one. So, I figured I'd line em up and snap a pic.



My wife insists there's something in our marriage contract that limits me to two motorcycles in the garage at a time. So, I gotta find a new home for the little 350. Probably end up back in storage.
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Old 07-25-2012, 12:32 PM   #10
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That looks just like an RXC, which is what they called your bike in 95. The ktm parts fiche lists a EXC620 as a model so that;s what you have. since you are 6 5, the starting drill isn't going to be that big a deal. Start shining her up for the TAT
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Old 07-25-2012, 03:30 PM   #11
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You should have a decomp lever on the left bar IIRC, right?

Cold starting should go like this, gas on, choke on, pull decomp & kick thru about 5-7 times, return kicker to top, release decomp lever and slowly push down till you feel kicker get hard to move, that is the compression stroke, pull decomp and push the kicker another inch down, it should go easily so don't go too far.

The engine is now set just past TDC of the compression stroke. Return kicker to top and kick thru solid & steady. You can't slap at it like a 125 and you don't need to jump up on it like a Harley, steady & firm to the bottom. It should light. If not, find comp again and repeat. Do not turn or even touch the throttle!

Hot start should be everything above without the prime kicks or choke. Find comp, get past it, kick.

No throttle! Most guys would place their right hand on the top of the bar rather than the throttle as just the slightest turn will foil the attempt. Sometimes when hot they need a few "clearing out" kicks, like after a fall. Pull the decomp and give it 4-5 with the throttle wide open. Repeat the past TDC drill, no throttle.

The exception would be if you install a pumper carb, like a FCR. With that you'd give it a few twists while priming it when cold only, 2-3 would usually do it.

Golly, new thumpers are easy to start!

I learned this next tip from a old BSA guy when my 620 kicker broke off at a MX race in 1999. It even helps my 570 Husaberg's e-starter!

Put the bike in gear and roll it backwards till the rear wheel locks up. You just put the engine at that same spot, past TDC of the comp stroke. Get it back in neutral without moving the piston and you should be able to bump start it in first gear! Like I said, even my e-starter likes this little treat as it gets the engine rotation started with a run at the compression stroke. sometimes the bike will just go wronk, wronk, when you hit the button. That means it is resting at the start of compression and missed the auto decomp on the cam.

My 620 would lock up solid while trying to bump it in 4th gear. He showed me this trick above and I could push the bike myself in neutral, jump on and slap it in first and it would start right up.

That is a good one to remember!
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Old 07-25-2012, 03:45 PM   #12
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I put about 70 miles on the bike today. Found that the vibration is there - but tolerable. Seems like it gets me in the feet more than anywhere else. I work in a polyurethane shop, I wonder if I could build some dampeners to fit the mounting bolts? I'll have to have a look.

Starting seems to be hit and miss with this bike. It was stone cold this morning and with full choke, it took two kicks. It sat at my office from 7:00-11:30. When I went home for lunch, it took several kicks - but I was trying to give gas as I kicked it and I don't think that works. It sat for 1/2 hour at lunch and started in two kicks - then I drove it 35 miles and it sat for about 2 hours. No choke, no throttle, started in 2 kicks.



Then I had a bit of a scare. I was about 20 miles from home and the bike starts spitting and sputtering at highway speed. Not what you want to hear on your second day with the new bike! The trip meter only showed 40 miles. Can't be out of gas already, can it? Oh yeah, I reset that when I got home with it yesterday - no idea how much gas was in when I bought it. Switched her to reserve an all was well.

So, I stopped for gas and about killed myself trying to get it started again. Kicked til my left leg hurt, then I got off the bike, stood beside it and kicked with my right. The first time it sputtered, the second with with my right leg fired it up. I don't know if I can get more force that way or what, but all the other starts were with me straddling the bike.

So, it's hit and miss. Mostly she seems to start pretty easily.

Yup, there's a few issues to address before I think about the TAT. The bars are way too low for me. The rear shock doesn't seem to have much dampening left. I turned up the top dial a couple of clicks and it didn't seem to help. The bottom dial is all the way to 11. Every once in awhile on the road, she'll slowly bob up and down a few times. I guess I've got to drop it of a ledge or hit a jump and see how the suspension reacts.

All in all, I'm pretty happy with it. Now, I just gotta learn how to keep that front end down. At least while on pavement, anyway!
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Old 07-25-2012, 03:52 PM   #13
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Quote:
Originally Posted by Navin View Post

No throttle! Most guys would place their right hand on the top of the bar rather than the throttle as just the slightest turn will foil the attempt.

I didn't see your post when I typed mine. But yeah - that part I learned the hard way!

Yup, decomp lever over by the clutch. I've been doing pretty much what you wrote - except for the 5-7 kicks while cold. Does that get gas in the carb?

And, I do like that bump start advice! I live on a hill and actually tried to bump start it in second - rear wheel slid to a stop. But, that makes a lot of sense to find the other side of TDC by rolling it backward!

Thanks!
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Old 07-25-2012, 03:56 PM   #14
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It gets a fuel charge into the cylinder. There is a ritual with the older 4t bikes, learn it, use it and enjoy it. Ignore it and you will find yourself exhausted and stranded.

Good luck with it, I loved mine for dirt, tried to keep a few more as street/DS bikes but the vibes drove me off them in a few thousand miles. Great, tuff machines.

Get that shock rebuilt before it spits you off!
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Old 07-25-2012, 04:17 PM   #15
gravityisnotmyfriend OP
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I just stumbled across this:

http://www.youtube.com/watch?v=FUxjZ...eature=related

can't tell if it's genius or very stupid. But, it's certainly effective!

Yeah, I'll get that shock taken care of. I don't know why I didn't notice it on the test drive, but that's the price you pay for buying an old bike!


I've got a good street bike for those long distance paved rides. This one will be used more as a dirt bike than a DS, but it's nice that I can drive it to the OHV parks instead of trailering it there.
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