1984 RM500 Restoration

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9/22/2020 8:58 AM

I picked up a new project for when the ATK gets finished up. This wasn't really on my radar, but it was fairly local to me and I had never actually seen one. I thought if I didn't pick this up, I would probably never have the opportunity again (unless buying a finished one).

The good? It was only 130 miles away. It is fairly complete. It has some brand new Fly Racing aluminum 7/8ths bars...which will find a good home somewhere else. It has a new heavy duty tube in the rear. The gas tank was razor bladed and sanded. Its not great, but its a pretty good start and the kid did a decent job. It will save me some time for sure. It also has a brand new Wossner overbored piston and recently bored cylinder. It makes very good compression. The price was $1000. I don't know if that qualifies as good, but I don't think its bad.

The bad? It doesn't run. It doesn't appear to be producing spark. The original TM carb slide is shot. The crank has a little wiggle on the stator. The plastic is all bad. The silencer looks like Mad Max handiwork. Obviously the suspension is shot as are the tires.

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9/22/2020 9:14 AM

A quick and dirty test showed correct ohm range for one of the stator poles - the other flashes numbers and then goes dead (to number 1). I'm guessing that's the problem, but not sure. After finding the crank wobble, I have now decided on a full engine disassembly whereas beforehand I was considering trying to fire it with the new top end.

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I picked up a cheapo Keihin wannabe carb because this bike is already looking to swallow a couple grand. Its not one of my prouder moments, but at this point I'm not sure if I'm lighting money on fire or if I can stay positive on this thing.

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A silver lining....two stage Uni Filters on each side that look to be in decent shape. I was expecting a nest of some sort.

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I will have to refurbish the exhaust in order to save money. I think the silencer is original to this bike, but I'm not sure. I tore into the homemade "tetanus shot" spark arrestor to see what I had to work with.

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I had the idea of spinning down an old tensioner pulley to use as a suitable endcap. I recently picked up this lathe and was excited to have it start paying for itself.

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Looks like I'll be able to chop the silencer down a bit and fit this puppy in the end. It may actually look alright too.

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9/22/2020 9:32 AM

I must compliment you on your excellent before images. Great shots.

This will be a challenging restore to say the least. It is very much like the 92 CR I did starting condition wise.
No way would I buy another in the same condition as that one. Just too much work when you have others that will need so much less.
I look forward to your efforts.

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9/23/2020 1:40 AM

Cool bike! At least it still has the DLS front brake assy. Hopefully it just needs crank bearings but inspect the case bearing pockets closely, they have inserts pressed in & become loose, so new bearings won’t help. The rear shock bodies also get worn out from lack of service. These bikes are rare! Good luck & keep posting!

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9/23/2020 6:37 AM

Good luck I'll be following.

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9/23/2020 12:55 PM

Nothing sounds better on these than the stock silencer.

Jealous

Following

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9/23/2020 5:57 PM

I once bought got a Chinese knock off keihin carb and it actually ran very good with it! No problems at all

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9/23/2020 10:19 PM

If the airbox covers are unmolested, those are worth some bank to concourse level restorers.

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The older I get, the faster I was.

9/24/2020 3:39 AM
Edited Date/Time: 9/24/2020 3:40 AM

Change oem Keihin jets, needle and slide return spring to Chinese Keihin and you are good to go. Chinese return spring is about 10 mm too short and can cause throttle slide to get stuck

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9/24/2020 6:13 AM

captmoto wrote:

If the airbox covers are unmolested, those are worth some bank to concourse level restorers.

They are drilled "black tape covering them." The drilling profile looks very nice too.

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9/24/2020 6:15 AM

JMX82 wrote:

Change oem Keihin jets, needle and slide return spring to Chinese Keihin and you are good to go. Chinese return spring is about 10 mm too short and can cause throttle slide to get stuck

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Thanks for that tip. I dont know how the Chinese spring can cause the slide to get stuck though. The cap needs to compress the spring before it can even be threaded.

Also, have you noticed inaccuracies between the same size jets chinese vs keihin?

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9/24/2020 9:34 PM

Micahdogg wrote:

Thanks for that tip. I dont know how the Chinese spring can cause the slide to get stuck though. The cap needs to compress the spring before it can even be threaded.

Also, have you noticed inaccuracies between the same size jets chinese vs keihin?

I haven't done any comparison between Chinese and oem Keihin Jets. I have always used Keihin jets because they are easy get from the local dealer and the price difference is not that big.

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9/29/2020 3:52 AM

Very cool! Could be a fun project. Quite possibly the best rear suspension ever.

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10/10/2020 5:13 PM

First batch of parts. Picked up some plastic and also a seat foam and cover. This is the safety seat foam, which goes up on the tank a bit.

I figured it would be best to mock up the seat, plastic, airbox, etc... because I'm confident that my seat rails are bent. This should help me figure out how bad, then I can repair and get the frame powdercoated.

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10/12/2020 5:34 PM

I ran a 1/2 bar in each frame rail, used a torch and straightened the subframe. I got it pretty well lined up and installed the seatpan, foam and fender to have a look.

Yeah I would say it is still pretty tweaked. I know the ergonomic are whack, but this seems a bit ridiculous. I will have to zip a pie cut out of the bottom of each of those rails and heave them down.

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10/17/2020 7:11 PM

Back with the grinder and welder. I ended up cutting the tops of each subframe rail and moving them down almost 2 inches! My welding and grinding was adequate. I think its strong enough for my needs...plus reinforced with the 1/2 rods in each tube so Im not saying it won't crack or break again, but I dont think my 210lb self will do it.

The body fits much better. We went from a 1 to an 8 outta 10. The bike is starting to feel ok to sit on. I can fudge a little more fitment with the seat foam, seat pan and mounting bracket to get it to a 9.

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10/18/2020 5:39 AM
Edited Date/Time: 10/18/2020 5:42 AM

Nice work... remember it’s a Suzuki, those frame rails needed to be re welded when it rolled off the assembly line👍Don’t forget to test fit the silencer mounting... I just went through this with a 92 Yz250, every time I had the seat & rear fender mounts correct, the silencer mount was off, took me several hrs to get it all correct. Removable subframe are worth their weight in gold!

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10/22/2020 6:03 PM
Edited Date/Time: 10/22/2020 6:06 PM

It’s amazing how much better that seat makes it look. I had the 465 - super plush and easy power. Ima smaller guy 5’7” and I loved that bike. Easy to ride

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10/23/2020 5:58 AM

Agreed on the newer style seat foam!

Speaking of, I attempted to mount the seat foam and cover last night but forgot about a couple seat repairs. The seat bracket mounts to a couple flimsy (and trashed) tabs that reside inside the seat pan. I took some scrap metal and welded a couple nuts here and there, then trimmed out my own new mounts.

Next, there are two nuts that sit at the tail of the pan...one was missing. I reused one of the old oem seat tabs from inside the seat and with help if a file and heat gun was able to press it into the seatpan. These mounts are a bit superficial as the fender has two stronger mounts on each side.

Also the seat cover seems to have a bit of excess material near the front so I glued a 3/4 inch chunk of foam to the pan to give me a little lift. Hoepfully I can produce a wrinkle free cover.

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10/24/2020 6:51 PM

I was able to get the seat foam and cover mounted finally. This was by far one of the most challenging covers I have ever done. It must be due to the fact that there is a tank protector now, yet there is no pan under that section to pull it tight. I adjusted it several times and barely got the wrinkles out up front, while not losing the "RM" placement in back....though the logos got stretched a bit. Glad this is done.

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