hello"! I like this bike! I watched the video with great pleasure. and I will watch the video of the continuation of work on it. thanks for the video! good luck !
I had one of those when they first came out. The trick was to hook up a condenser to the cdi, otherwise did not have any low end, stalled easily. Can't remember exactly how it was done though.
When I got the bike from my dad it had a bad CDI box. I found a whole new and modern CDI/Coil/Stator online for about 300 bucks and put it in, seems to work great
I've got an old special edition" Dirt Bike" magazine Tech tips , and in it ,there's an article about fitting a condenser to an SC500, a friend of mine had an SC years ago , and did the modification, with pleasing results.
I have my mom's old 71 DT 1250 which looks similar. Same as yours the bottom end of the engine was already done back in the '80s but everything else was bolted back on as is. Background 2012 I reconditioned the bike and when I pulled the head you could see the black streaks where the compression was leaking past the gasket. It was only on the head side so I skim cut the head to get it flat bolted it back together and it ran like a champ. I know that bike had a RT 360 carburetor on it and it runs pretty well, it never had a problem with the carburetor. Just pull out your plug and take a look at it, it'll tell you a lot if you look up what it's supposed to look like and what it's not. I've always heard the sprocket gearing was terrible but since I've never owned one of those I don't know what good gearing would be you'd honestly have to jump on an old Yamaha enduro site and start asking some questions. There's also cylinder head mods that can be done to help with the detonation but I would have to say a good octane fuel like 100LL down at the airport with absolutely no ethanol would be the way to go. Can't wait to see how it turns out ;)
I forgot how the foot pegs barely stick out further than the swingarm bolts. Had to run octane boost on mine. I put a hand lever compression release in the second spark plug hole. Flat tracker special for sure friend0.
the kicker decomp seems alright. I cleaned it/took it all apart to make sure it was free. its actually not too bad to kick over with it disconnected, but im used to kicking over a 600. The foot pegs are stubs there like you said, im surprised I can use the rear brake at all
nice bike , i didn,t know they made a 500 i have an 87 490 that needs put together . they have that weird purring sound , i think thats normal , i had a 400 that did that . maybe the exhaust or the jetting , i think its a carburation thing , but ive heard that before with those older Yamaha big bores . as long as it starts easy and runs good .
Huge Single cylinder 2 strokes are like that, My suzuki and Yamaha 400 and 490 were like that. Unpredictable surges in power at NO THROTTLE! SCARY BIKES!
My Neighbor had a Yellow one his must have been a 1974 Model .. Specs say it has Oil Injection, I am curious about that .. Oil Injection is great for trail riding.. says 44 HP
@@bmfbbmfb I used Bel-Ray and Golden Spectro for years at 40 to 1 or a little richer.. Now days I was using Klotz just bought 4 gallons of Lucas.. for at least $10.00 per gallon less than the Klotz is ..
was rebuilt before it was parked in the 80s. def true on the HG though, I started it today and after it got hot I heard that sound and I was looking around the head and saw it was wet all the way around. I checked the headbolts and they were baarly tightened so I took them to 20ftlbs and the sound went away, and its making more power. I have a new HG though if this ones still leaking. Hopefully the head stayed flat, but I do have a spare motor with it
@@bmfbbmfb I have an aircooled TS 250 that rattled alot and it just got worse so i rebored her now she's sweet as a nut silky smooth running . Love the 500 mate never seen one in England. Great vids mate keep it up 😎
I just got one at my job we are a warehouse and the back been their since 1980 my boss said keep it a know after this video I’m going to get it running. I never worked on a bike in my life gonna now
Aside from the suspension being short compared to pro-link style bikes its a great machine and pretty simple to run. The worst part is the ignition...if youve got spark youve got yourself a bike. If not you have options now a days at least. I was able to get an entire new stator/coil/control mod for this bike for under 300 bucks and only needed some light modification. Good luck youtube friend
it was a thing they did back then, it was so you would have a backup plug if the first one fouled out. Good for racing, no tools needed just switch the plug wire over and kick it over on a new plug
Agree. I bought a set of jets, and im waiting for a warm day. I replaced the primary side seal but im waiting for a clutch to come in to replace the wet side. I found out the head was a tad loose...might explain the leanness too, pulling a touch of air in from the head 'seal' instead of fuel'd air from the crankcase.
@@bmfbbmfb sounds like a good plan.. i came close to blowing up my 77 RM 125 .. went way too big and then backed down the jet sizes ..32 to 1 also will make it last the longest .. any of the ester fortified synthetics or Redline will make the engine last its longest..best of luck and hammer down!
think its an 82, jetted one bigger than factory. They were rich from the factory from what I read. I tried going one step richer and it hated it, so im back (all after this vid)
@@bmfbbmfb I think cycle world said they were rich from the factory. Could be air leaks causing a lean condition. Too many possibilities on these old bikes. Just be careful with it, these things will ping themselves to death in no time if there is anything off with fueling.
Love the graphics on the tank, man this is a really awesome bike. I’d love to ride it for a day on some trails.
Cool bike dude I like it 👍🏻💯
hello"! I like this bike! I watched the video with great pleasure. and I will watch the video of the continuation of work on it. thanks for the video! good luck !
Quick old beast. Them aircooled 70s bikes are far underrated- enjoy!
🇦🇺😎👍I don’t remember ever seeing them in Australia
of course it'll make it around the block, it's a Yamaha, nice bike btw, I have a 77 YZ 400 I'm restorin myself.
I had one of those when they first came out. The trick was to hook up a condenser to the cdi, otherwise did not have any low end, stalled easily. Can't remember exactly how it was done though.
When I got the bike from my dad it had a bad CDI box. I found a whole new and modern CDI/Coil/Stator online for about 300 bucks and put it in, seems to work great
.006 cyl and piston doesn't stick
I've got an old special edition" Dirt Bike" magazine Tech tips , and in it ,there's an article about fitting a condenser to an SC500, a friend of mine had an SC years ago , and did the modification, with pleasing results.
I have my mom's old 71 DT 1250 which looks similar. Same as yours the bottom end of the engine was already done back in the '80s but everything else was bolted back on as is. Background 2012 I reconditioned the bike and when I pulled the head you could see the black streaks where the compression was leaking past the gasket. It was only on the head side so I skim cut the head to get it flat bolted it back together and it ran like a champ.
I know that bike had a RT 360 carburetor on it and it runs pretty well, it never had a problem with the carburetor. Just pull out your plug and take a look at it, it'll tell you a lot if you look up what it's supposed to look like and what it's not.
I've always heard the sprocket gearing was terrible but since I've never owned one of those I don't know what good gearing would be you'd honestly have to jump on an old Yamaha enduro site and start asking some questions.
There's also cylinder head mods that can be done to help with the detonation but I would have to say a good octane fuel like 100LL down at the airport with absolutely no ethanol would be the way to go.
Can't wait to see how it turns out ;)
Yes great old bike, I have a 79' yz 400 that I need motor parts for, maybe even whole engine
I forgot how the foot pegs barely stick out further than the swingarm bolts. Had to run octane boost on mine.
I put a hand lever compression release in the second spark plug hole.
Flat tracker special for sure friend0.
the kicker decomp seems alright. I cleaned it/took it all apart to make sure it was free. its actually not too bad to kick over with it disconnected, but im used to kicking over a 600. The foot pegs are stubs there like you said, im surprised I can use the rear brake at all
nice bike , i didn,t know they made a 500 i have an 87 490 that needs put together . they have that weird purring sound , i think thats normal , i had a 400 that did that . maybe the exhaust or the jetting , i think its a carburation thing , but ive heard that before with those older Yamaha big bores . as long as it starts easy and runs good .
Huge Single cylinder 2 strokes are like that, My suzuki and Yamaha 400 and 490 were like that. Unpredictable surges in power at NO THROTTLE! SCARY BIKES!
Um abraço do Brasil!
Nice old bike
Try stretching the slide spring in carb or it could be main seals on way out.
My Neighbor had a Yellow one his must have been a 1974 Model .. Specs say it has Oil Injection, I am curious about that .. Oil Injection is great for trail riding.. says 44 HP
feels like it makes 44 when shes full tilt. It had oil injector but its been deleted so im all premix now, running about 30-1
@@bmfbbmfb I used Bel-Ray and Golden Spectro for years at 40 to 1 or a little richer.. Now days I was using Klotz just bought 4 gallons of Lucas.. for at least $10.00 per gallon less than the Klotz is ..
Too powerful and scary for me 😀 My favourite bike was my Honda S90. Lol.
We need to inspect the balance shaft chain while were in there servicing the clutch/crankseal.
i recommend u bringing it a workshop they might be able to improve the engine and improve the exhaust
everything The workshop cam do you can do in the average garage. Just cheaper
Sounds like head gasket mate could do with a rebore as well
was rebuilt before it was parked in the 80s. def true on the HG though, I started it today and after it got hot I heard that sound and I was looking around the head and saw it was wet all the way around. I checked the headbolts and they were baarly tightened so I took them to 20ftlbs and the sound went away, and its making more power. I have a new HG though if this ones still leaking. Hopefully the head stayed flat, but I do have a spare motor with it
@@bmfbbmfb I have an aircooled TS 250 that rattled alot and it just got worse so i rebored her now she's sweet as a nut silky smooth running . Love the 500 mate never seen one in England. Great vids mate keep it up 😎
The old two strokes tuned for torque. Far better than the later models who chased hp.
for trail riding stuff it def is. I wanna get into some kinda scramble and see how bad i get smoked
I just got one at my job we are a warehouse and the back been their since 1980 my boss said keep it a know after this video I’m going to get it running. I never worked on a bike in my life gonna now
Aside from the suspension being short compared to pro-link style bikes its a great machine and pretty simple to run. The worst part is the ignition...if youve got spark youve got yourself a bike. If not you have options now a days at least. I was able to get an entire new stator/coil/control mod for this bike for under 300 bucks and only needed some light modification. Good luck youtube friend
Maico 500 MC enters the chat ^^
Why does it have 2 spark plugs?
it was a thing they did back then, it was so you would have a backup plug if the first one fouled out. Good for racing, no tools needed just switch the plug wire over and kick it over on a new plug
sounds a bit lean ... should be smoking a little bit ...go one size bigger pilot ... do crank seals ... you are close ...
Agree. I bought a set of jets, and im waiting for a warm day. I replaced the primary side seal but im waiting for a clutch to come in to replace the wet side. I found out the head was a tad loose...might explain the leanness too, pulling a touch of air in from the head 'seal' instead of fuel'd air from the crankcase.
@@bmfbbmfb sounds like a good plan.. i came close to blowing up my 77 RM 125 .. went way too big and then backed down the jet sizes ..32 to 1 also will make it last the longest .. any of the ester fortified synthetics or Redline will make the engine last its longest..best of luck and hammer down!
Was pinging pretty hard during that ride. It's lean everywhere. What jets are in it currently?
think its an 82, jetted one bigger than factory. They were rich from the factory from what I read. I tried going one step richer and it hated it, so im back (all after this vid)
@@bmfbbmfb I think cycle world said they were rich from the factory. Could be air leaks causing a lean condition. Too many possibilities on these old bikes. Just be careful with it, these things will ping themselves to death in no time if there is anything off with fueling.
Sounds like an air leak.
32 to one