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Klaus Welch

1981 DR500 Restore

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DR500.jpg.2c3fb9ecff53d10388f31792efe1b33d.jpgHey everyone.  First post here, but it appears TT is the best place for this sort of thing, looking forward to being apart of the community.  Above is a picture of the 81' DR500.  My son thought it was a blast to hold the bike up.

TLDR: Got a running 1981 DR500, going to spruce it up, possibly make it street legal, bring it back to it's former glory.  Any words of advice or encouragement would be appreciated.
 

A friend of mine was moving out of state (Alaska) and didn't want to make another 2k+ mile trip to get the last of his stuff.  So he gave me two free dirt bikes.  A 1981 DR500 and 99' KX250.  The DR500 already ran, and ran fairly well, but needs some TLC.  I figured I was given the bike for free, so dropping anywhere from 300-600 bucks into it couldn't hurt.  Keep it mind, I've never owned or really ridden a dirt bike prior to this.  But saw tons of "Do's and Don'ts" for dirt bikes and think I've got a fairly good handle on it.  I've probably ridden the bike 10-15 miles already, seems to have plenty of power and compression.  I have ridden snowmobiles/4 wheelers since I was a kid so I'm not new to power sports.  If it's got a motor, I'll figure out how to ride it in short order.

Below is a list of everything I've bought to get this bike back into good/great working order.

Bought or Have Plan/Fixed Already
* The bike already had the handlebars/grips swapped to Renthal aluminum's from the previous owner.
* Bought factory gas cap, the old one split.
* Bought a set of Kenda K270 tires as the old M23 set is cracking bad.
* Got a set of HD tubes for the tires as well.
* Have a local place rebuilding the original dual rear KYB shocks.  They will be taking the shocks apart and giving me the spring and body.  The springs will be shot peened at a friends work and I'll repaint them black like factory.  The body will be carefully sanded and repainted to close to factory silver/metal color.  New o-rings, oil and nitrogen fill.
* Chain is going to be cleaned in kerosene when I take the tires off to swap in new K270's so that I can clean the sprocket off really well.
* Plastics are going to be sanded and buffed to bring back original look as they are oxidized.  Was trying to avoid getting generics, but may go that route if they don't turn out well.
* I have a factory DR500 dealer service manual that should be here shortly that I picked up for $35 online, not a reprint or loose leaf, the bound version.
* Thoroughly cleaned the air box and cleaned the air filter properly.  Re-oiled with Maxima filter oil.  Bike began to idle and run MUCH smoother.

To Be Address
* Forks seem to be leaking oil, so those will likely need a rebuild.  I've watched a few videos of forks being rebuilt, it looks fairly involved.
* There is the smallest leak in the gas tank.  No aftermarket or decently priced and not leaking tanks available.  I'm curious if I could have someone weld/brazen the area effected and then grind with a disk the material down.  Similar to body fill, but to hold gas.  The entire tank should be stripped, body fill for small dents, and then repainted anyhow.
* I noticed lots of blue vinyl graphics for these bikes online, but nothing for the orange and red enduro models.  Anyhow have an idea of who could recreate these without being stupid expensive?  Almost consider cutting them myself /shrug.
* Seat needs a new cover.  Smallest amount of foam missing in the rear, not a big deal.  Is there any sort of seat foam you can make and put/glue on and then cut it to shape it like the original piece?  I'd consider something like that and get a new cover.

Possible Modifications

* These bikes are 6v.  If I recall from the little bit of literature I found on it, the bike produces like 45w at 6v.  I'm seriously considering converting the bike to 12v just for all of the lights.  This would allow me to add a nice LED headlight as opposed to the anemic 6v little light in it.
* Possibly making it street legal.  I realize there is a landmine of hurdles to overcome to get this thing legal on road and registered as such, but so long as it's not stupid expensive (thousands), I'm willing to give it a go.  Even the tricks where you have it registered in another state and do a title transfer.  This was part of the reason I picked up the Kenda K270 which are DOT approved and they get good reviews all around, and great off road, decent on road.  I wouldn't be using the bike for much more than 15-20 mile one way commutes, so no long 100's of mile rides.
* Making it street legal would require me to setup the bike with a 12v battery for charging and running the lights I believe as well.

Anyone with input, suggestions, warnings, ect are welcome.  At this point, I'm getting the bike in good working order, going to go through the service manual and perform every maintenance item on the list to give it a once over, probably even checking the valve timing.

 

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Well, just as I finished this post, my new tires came in.  Excited to get these swapped and shocks back on.  I can ride it around trails at that point at least.

IMG_20200519_151156.jpg.6d46e17ddd2e16648224a920a010d9d5.jpg

Edited by Klaus Welch

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your son looks excited, i'd sure be!

you have a good plan. i'd try to find a plastic tank to adapt instead. 12v conversion is the only way to go imo, i've done it to 2 yamahas and neither of my 2 riders have batteries.

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Posted (edited)

"Chain is going to be cleaned in kerosene"

welcome but no biker i know of cleans his chains with kerosene..... maybe back in the swinging sixties 🙂

if you have there an o-ring chain, kerosene will swell the rubber and destroy them eventually

if its a non-O-rign chain, kerosene will wash out the little grease there, but best if you dont even use it, it's pre-historic

a cheap new O-ring chain is highly recommended for your own safety, dont skimp on sttuf like that. a snapped chain can cut through enogne parts, legs and leave you stranded middle of nowhere

highly doubt that those shocks are rebuild able (and at what cost)

for 188$ get a pair of these and put your painted springs on

https://www.amazon.com/Progressive-Suspension-13-1241B-Powder-Pressure/dp/B000GUWOA8

Edited by turboguzzi

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@plugeye

Yeah, he was excited to ride on it with me.  I'm not ready for that obviously as I am just starting out.  A few weeks after that photo he got a chance to ride a friends 50cc and just was ripping on it.  He wont stop telling me how he wants a dirt bike now to ride with me :D.  I considered the plastic tank options, and have seen someone use an older RM250 tank on one of these bikes.  How does one go about finding a tank that will fit, it seems like you'd have to burrow one or buy it outright before you even know if its possible to adapt a tank.

If you've got any information that you could provide to help with how I'd convert this over to 12v, I'd be eternally grateful.  In my searches, it seems like the details are left out.  But I understand it usually takes a swap of a regulator/rectifier.  I'd like to avoid modifying the ignition (CDI?) portion if possible.  I'd imagine it should be possible to convert to 12v after that portion of the wiring so that only the lighting system is on 12VDC.  From what I've seen so far, I should have about 45w to play with.  I was hoping with everything being LED, and adding a battery that I'd be able to keep this thing below that power allowance.

@turboguzzi
Really, no one cleans in kerosene?  Odd, everything I found about cleaning a chain kept saying to stay away from gasoline, WD-40, ect.  They would constantly point to chain manufacturers suggesting kerosene /shrug.  What is best for cleaning a chain before lubing it?  I bought some Bel-Ray chain lube.

On second look, I don't believe this chain is O-Ring, it's just a standard.  So yeah, once I have the back tire off to clean it all out, I'll just slap on a new chain for peace of mind.  Is there any reason someone wouldn't want an O-Ring or X-Ring vs a standard?

Thanks for the recommended shocks!  I wish I had seen those before.  I just picked back up my shocks last night from the guy who was going to rebuild them.  He confirmed they aren't re-buildable.  Once he had the spring off, you could see how much more worn out they were.  Both surprisingly still had some oil in them 40 years later!  I had bought a set of those cheapo RFY shocks as a hold me over because I couldn't find anything that was original length (400mm eye to eye).  They ran me $83 and apparently when rebuilt and charged properly, they perform fairly well.  He looked them over and was surprised at how nice they were for $83 and is going to take them apart to put real oil in them and nitrogen charge them properly.  That will cost me about $100 total.  So I'd be in a set of shocks for about $180 with new springs.  I don't plan to be doing crazy off-road jumping or MX with this bike, so the loss of 1" travel is acceptable.  If everything else rides well and I just don't like them, I'd consider upgrading those a few years down the road.


I also just found out I need to apply for surety bond as there was no title for this thing and according to the VIN it's never been registered in my or any other state... wow, 40 years lol.  I contacted Suzuki about the bike and they say they can't pull up any additional info for me hahaha.  Glad I have a dealer service manual heading my way.

Thanks again guys.  I'll be posting pictures of things as this project progresses if anyone cares to check it out.

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I now realize that its the same as paraffin over this side of the atlantic,  so my bad and you are right.

if you cant see the black o-ring between the outer and inner plates then it's a regular one. almost nobody uses them any more other than all out racing (and replace often) or very low power. so yes, get  a decent o-ring one or x-ring if you can afford a bit more.

 

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2 hours ago, plugeye said:

heres a simplified diagram i use. no changes to the ignition system, only lighting. its a cheap 12 volt regulator, 12 volts AC

12volt AC lights.jpg

Awesome!  Yeah, I was hoping it would be that simple, that's exactly what I had imagined.

I'm going to have to add turn signals and the headlight will need to be high/low beam but I'd imagine that is just a matter of wiring the proper stuff in after the regulator.  So you don't have issues with undervolting on a LED headlight (flickering, ect) or are you not using LED?

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Plug, just out of curiosity, how does that cheap regulator look like (or link to one...)?

i only know 12V regs with input wires form charging coil and 12V outputs, never seen one that's just +&-

 

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ok, saw some now, they are called around here "moped regulators"

not that i need one but good to know....

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Posted (edited)

Where is the tank leaking on the back mounting tab? My one was I just braised it up its been good for 18 months. Another option is a tank liner which will. Seal. It from inside.for the decals just get the image your after off google and take to any decent sign shop they can scan and reproduce themselves 

Edited by vince 1
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