Good morning dear friend and brother Dale. Thank you for another in the shop work. I grew up as a kid in the Island of Puerto Rico and around 1972 to 1973 I had that very same model Yamaha 80 2 stroke bike and this bike was so much fun. The little Yamaha is a time capsule of a mini vintage bike that brings back great childhood memories that at the time as a kid I had no cares in the world.. God bless you my dear brother Dale for your spirit and wisdom. Ricardo in Southwest Florida. Prayers please for our State as a hurricane named Milton is expected by Wednesday as if Ian and Helene did not hurt already so much.. 🙏🙏🙏
Awesome that you are working on the GT80! You are correct in saying that is where most of us started. Looking forward to seeing if the rod bearing is bad as well or just the crank bearings.
This is a great project, am having fun diving into it. I think all the bearings and the rod will be bad; customer brought me all the parts, so I am ready to go.
Finally a GT 80, I’m just about to start my sons GT80 engine build so me and him will both be watching all of these. Thanks again for the great Videos Dale.
A little gem Dale. My brother had a 1980 MX80 which was the same as the GT80 without the headlight. Gentle kids bike 4 speed. Cute! Just noticed the same tank cap. And I remember having to pull out and straighten the clutch push rod near the front sprocket as it was bent from something being caught in the drive chain one time. Can see this in your video when you removed the side cover. We used to thump around the bush in the Blue Mountains west of Sydney when we were kids in the early 80s. I was on my 77 TS125C. Nice memories. Still have to repair my 76 TS250A, that I mentioned to you a while back. Maybe over Xmas this year. Kind regards and Merry Xmas 2024! Craig
Thanks Craig, Oh the memories, bikes and kids, our first since of freedom. Yes, the clutch rod is a tiny thing on these bikes, I can see it to be a potential problem area. Yes, it's time to get started on your TS250. I had so much fun riding around on my 75 model this past summer, great bike.
That is one sweet little bike Dale! I wish I could have found one like that back when my daughter wanted a bike, when she was 12. I bought her a little Tomberlin 110cc pit bike, and she never took to it. SO then I got her a Suzuki LT80 quad, and she STILL loves and rides that little thing, and she's about to be 28 years old now. As always, I know it's going to be a good day to see a new post from you.
Thanks Johnnie, glad to hear your daughter is still interested in the quad, it really never ceases to be fun if you were bitten by the bug. Looky here, I'm still doing it almost 60 years later, but I only like the old ones. Have no interest in the newer bikes.
I had a 1965 Yamaha 250 Catalina. When I rebuilt the engine in the early 70's, Yamaha had a Allen Bolt kit to replace all the Phillips screws. Loving your videos Dale.
Thank you, yes there are bolt kits for most of the older Yamaha's still. They are certainly better, but most of the time folks want the original style screws these days. Go figure!
What a cool little bike! Friend of mine from long ago had this same one! What a blast from the past. Going to really enjoy this project as it takes me way back.
Hope you’re doing well Dale. What a beautiful little GT80. I could hear the bearings grind immediately. 🤣 I have an Rm465 engine like that- but it’s a good core.
Hey buddy, how's things in the lone star state? Yes, I am sure they are toast. You should build that 465 up and put in the 250 frame. Or better yet start looking for a bike without an engine. LOL
Cute little bike Dale. It will be good fun once it's had the crank refreshed. The engine looks very much like the TY80 we had over here. Best wishes, Dean.
The 80 really is a cute little bike, being a scaled down version of its bigger brothers. Bet that would really go with a 90-pound kid on it. Can't believe the low miles and incredible shape it's in. A true survivor for sure.
That was a great selling point for the manufactures to make completive minibikes with spoked wheels, just great that they looked like the one that dad's rode too. I think I said it had miles on it in the video, actually this one is KPH whatever that works out to in miles, think it's even less.
@@montana2strokeracer Yes, the 576 kilometers equals just 358 miles! Incredibly low miles or unhooked the cable. Looks like actual from the video though.
Hello Dale. Love your channel. Im doing old yamahas to. They Are called fs1 in Denmark. The skrews on the motor is called Jis and is not Philips skrews. The grove is sligtly different. 😃
Hi there, I have heard of the FS1 bikes, very popular over there. Just as fun as these are. Yes I have a set of JIS drivers and use them everyday. Phillips is just a term that folks over here use because they are more popular.
I don't think that's not an original key switch. My 78 is either on or off. Awesome to see that you're working on one of these though for sure! I absolutely love mine, although I wish it had some more power I must admit lol.. I have made mine a little quicker by installing the transmission gears out of a 74-75 YZ80, a piston and rings from the same yr YZ's, and some minor port work. I have a different carb on the way hopefully that I can make work on the old girl. Will find out on Monday. Fun little bikes regardless though. Thanks for all the great videos Dale!
Awesome Cody, it looks like a lot of the parts from the later models fit the older. I will check out the wiring, I think they have a couple wires crossed.
I found 73 this summer at a garage sale for $75. Had a chrome tank. Made it into a rider and sold it to a 13yo old girl. Peppy little bikes. These are a neat size. Tank and everything cosmetic looks good on this one 👀. Worthy salvage.
@@montana2strokeracer I was happy to sell it to someone that was going to ride it. Kids usually want the newer looking bikes. The chrome tank was nifty. Idk if it was Yamaha Christmas special or something someone did. The components were gold. It was an enduro originally
It was just something that didn't seem right to me. The bike is here for engine work so that is what I will do. I will let the customer worry about the switch unless he wants me to look into it. I do bet your right though, just a couple wires switched.
im thinking you are rite about the switch, left should be run with no headlite ,, middle should be off and right should be run with lights turned on, just my 2 cents worth, another good vid dale, catch you on the next one...
@@montana2strokeracer Yeah, I use one all the time. With all the modern electric tools, you still can't beat the old impact driver. I remember the days when they were sort of expensive and rare, and only dealerships had them.
regular motorcycle oil. 10-30w stay away from car oil as a lot of it has friction modifiers that affect the clutch (making it slip) folks use rotella diesel oil too.
Motorcycle oil is correct! Although the "car oil" will work for a time, it does not have the proper additives for use with the wet clutches that these bikes have. I run into this problem a lot with older quads as well as these older bikes. I have 8 of these bikes myself and thoroughly enjoy riding and wrenching on them. ❤❤🙂🙂👍👍@MegaWildweasel
Just 10/30 motor oil. That is what the manual calls for. Remember at that time synthetic oil was just starting to come out. So, most motor oil back then was petroleum-based oil. I have had many folks come into the shop with slipping clutches, when asked if they were using synthetic or semi-synthetic oil, all that were, a change to petroleum-based oil is all it took to fix the problem. In the 60s, and 70s these clutches were designed for regular car motor oil. Regular Car motor oil (petroleum based) from Napa in 10/30 is all I use in these older bikes.
Good morning dear friend and brother Dale. Thank you for another in the shop work. I grew up as a kid in the Island of Puerto Rico and around 1972 to 1973 I had that very same model Yamaha 80 2 stroke bike and this bike was so much fun. The little Yamaha is a time capsule of a mini vintage bike that brings back great childhood memories that at the time as a kid I had no cares in the world..
God bless you my dear brother Dale for your spirit and wisdom. Ricardo in Southwest Florida. Prayers please for our State as a hurricane named Milton is expected by Wednesday as if Ian and Helene did not hurt already so much..
🙏🙏🙏
These are cool little bikes; lot of kids made their lifetime memories on them. You folks are in my prayers my friend.
As ever just love your analysis and craftsmanship
Got to love you Americans. 'Guy just brought this down from Canada'.
Thank you. Well, you see.....Canada is only 100 miles north of me. It's not like it's a whole country away. LOL
Awesome that you are working on the GT80! You are correct in saying that is where most of us started. Looking forward to seeing if the rod bearing is bad as well or just the crank bearings.
This is a great project, am having fun diving into it. I think all the bearings and the rod will be bad; customer brought me all the parts, so I am ready to go.
Finally a GT 80, I’m just about to start my sons GT80 engine build so me and him will both be watching all of these. Thanks again for the great Videos Dale.
Thats great David, hope some of this will be helpful to you guys. Nice to see a father and son doing a project like this.
A little gem Dale. My brother had a 1980 MX80 which was the same as the GT80 without the headlight. Gentle kids bike 4 speed. Cute!
Just noticed the same tank cap. And I remember having to pull out and straighten the clutch push rod near the front sprocket as it was bent from something being caught in the drive chain one time. Can see this in your video when you removed the side cover.
We used to thump around the bush in the Blue Mountains west of Sydney when we were kids in the early 80s. I was on my 77 TS125C. Nice memories. Still have to repair my 76 TS250A, that I mentioned to you a while back. Maybe over Xmas this year. Kind regards and Merry Xmas 2024! Craig
Thanks Craig, Oh the memories, bikes and kids, our first since of freedom. Yes, the clutch rod is a tiny thing on these bikes, I can see it to be a potential problem area. Yes, it's time to get started on your TS250. I had so much fun riding around on my 75 model this past summer, great bike.
Hi Dale, been waiting for this one! Thanks for taking the time to upload these videos and sharing your knowledge!
Thank you, sir, this is going to be fun. Too bad all I get to work on is the engine.
Brings back memories of a good friend who the exact same bike rode right from the house into hills north of kamloops bc.
That is one sweet little bike Dale! I wish I could have found one like that back when my daughter wanted a bike, when she was 12. I bought her a little Tomberlin 110cc pit bike, and she never took to it. SO then I got her a Suzuki LT80 quad, and she STILL loves and rides that little thing, and she's about to be 28 years old now. As always, I know it's going to be a good day to see a new post from you.
Thanks Johnnie, glad to hear your daughter is still interested in the quad, it really never ceases to be fun if you were bitten by the bug. Looky here, I'm still doing it almost 60 years later, but I only like the old ones. Have no interest in the newer bikes.
So glad you are working on a mini!! The last year I’ve been working on mine. Always things to learn!
Right on Nick, glad to see ya working on one. I know man, I learn something new every day.
I had a 1965 Yamaha 250 Catalina. When I rebuilt the engine in the early 70's, Yamaha had a Allen Bolt kit to replace all the Phillips screws. Loving your videos Dale.
Thank you, yes there are bolt kits for most of the older Yamaha's still. They are certainly better, but most of the time folks want the original style screws these days. Go figure!
What a cool little bike! Friend of mine from long ago had this same one! What a blast from the past. Going to really enjoy this project as it takes me way back.
They are awesome, even cooler if you had anything to do with them back in the day. Thanks buddy
Good morning Dale, I remember these, I had the 1971 Yamaha JT1 60 4speed. Enjoying the videos still.
Such a cool little bike! Great shape too aside from the bearing noise. Not many kids kept them in that nice of condition!
Hey Matt, you bet, cool is an understatement. This one is really nice for sure, some new bearings and a rod, it will be good as new.
Thanks Dale , You got to love the Mini Enduros . So darn much Fun .
Right on brother, I dig the mini's too. Lot of fun.
Hope you’re doing well Dale. What a beautiful little GT80. I could hear the bearings grind immediately. 🤣 I have an Rm465 engine like that- but it’s a good core.
Hey buddy, how's things in the lone star state? Yes, I am sure they are toast. You should build that 465 up and put in the 250 frame. Or better yet start looking for a bike without an engine. LOL
Great show Dale. Enjoy watching you. Keep up the good work.💯🏁👍
Thank you, Bill, nice to have you along on the ride.
Cute little bike Dale. It will be good fun once it's had the crank refreshed. The engine looks very much like the TY80 we had over here.
Best wishes, Dean.
Hey Dean, yeah, I have had a rash of these burned up cranks lately. But it will be fun diving into it to see the extent of the carnage.
That's a sweet little bike! It's going to come up beautifully mate.
Cheers, Peter.
Thanks Peter, yes, it is, they are hard to find these days. Going to be fun.
Already looking forward to the next one Dale.
Me too Mike. Looking forward to finding out all the issues, and then repairing them.
The 80 really is a cute little bike, being a scaled down version of its bigger brothers. Bet that would really go with a 90-pound kid on it. Can't believe the low miles and incredible shape it's in. A true survivor for sure.
That was a great selling point for the manufactures to make completive minibikes with spoked wheels, just great that they looked like the one that dad's rode too. I think I said it had miles on it in the video, actually this one is KPH whatever that works out to in miles, think it's even less.
@@montana2strokeracer Yes, the 576 kilometers equals just 358 miles! Incredibly low miles or unhooked the cable. Looks like actual from the video though.
Hello Dale. Love your channel. Im doing old yamahas to. They Are called fs1 in Denmark. The skrews on the motor is called Jis and is not Philips skrews. The grove is sligtly different. 😃
Hi there, I have heard of the FS1 bikes, very popular over there. Just as fun as these are. Yes I have a set of JIS drivers and use them everyday. Phillips is just a term that folks over here use because they are more popular.
73 , first year GT80. The gtmx was silver with a purple stripe.
I don't think that's not an original key switch. My 78 is either on or off. Awesome to see that you're working on one of these though for sure! I absolutely love mine, although I wish it had some more power I must admit lol.. I have made mine a little quicker by installing the transmission gears out of a 74-75 YZ80, a piston and rings from the same yr YZ's, and some minor port work. I have a different carb on the way hopefully that I can make work on the old girl. Will find out on Monday. Fun little bikes regardless though. Thanks for all the great videos Dale!
Awesome Cody, it looks like a lot of the parts from the later models fit the older. I will check out the wiring, I think they have a couple wires crossed.
Last year I bought a 1973 dt175 & the ignition switch worked backwards, & I ended up getting a genuine Yamaha switch & that works as it should
my 73 tc-100 is American market i did notice the Canadian bikes had a different wire diagram for light switch.
Yes there are some differences in the US and CA models.
A very cool little bike.
Camera "Fish Eye" or are the front fork tubes bent to the rear?
No, it's the wide-angle lens I use, they are straight as an arrow
I found 73 this summer at a garage sale for $75. Had a chrome tank. Made it into a rider and sold it to a 13yo old girl. Peppy little bikes. These are a neat size. Tank and everything cosmetic looks good on this one 👀. Worthy salvage.
Good find Vinny, bet the young lady is having fun with it.
@@montana2strokeracer I was happy to sell it to someone that was going to ride it. Kids usually want the newer looking bikes. The chrome tank was nifty. Idk if it was Yamaha Christmas special or something someone did. The components were gold. It was an enduro originally
Cracking looking bike
My first of many bikes.
Gorgeous bike!
Thats a nice engine...2 strokes are fun.
Thanks for sharing your email Dale. 👍
Thanks, buddy, yes, it is a nice engine, a bit different than the AT and CT's, but I will learn as I go. I really enjoy the two strokes myself.
You made removing the chain link look easy!
Well, thank you Graham.
That is a nice little bike.
ck harness under tank , wire connector
block unpluged
not letting key switch ground.
we used to start by just unplugging that block.
or it is wired wrong in the headlight bucket? looking at an owners manual it is wired wrong. pos 1 off pos 2 run no lights and 3 run lights
It was just something that didn't seem right to me. The bike is here for engine work so that is what I will do. I will let the customer worry about the switch unless he wants me to look into it. I do bet your right though, just a couple wires switched.
@@MegaWildweasel trust me, if you
unplug connector
under tank or cut
harness bike will start. This one aint in the book.
@@garyfyvie9490 I never said it wouldn't work read what I posted pls. have a nice day.
Great bike
They sure are, not many left.
nice little bike there dale main bearings are shot possibly crank 2 sure ul sort it great video as always next one please
Had a rash of crankshaft problems lately. It's all-fun exploring these things.
im thinking you are rite about the switch, left should be run with no headlite ,, middle should be off and right should be run with lights turned on, just my 2 cents worth, another good vid dale, catch you on the next one...
I think so too James, just a couple wires crossed I think.
A nice clean bike. They used Philips screws on my 87 rz350.
It sure is John, I really don't mind the Philips screws, you just have to have a hand impact driver, no problem if you do.
@@montana2strokeracer Yeah, I use one all the time. With all the modern electric tools, you still can't beat the old impact driver. I remember the days when they were sort of expensive and rare, and only dealerships had them.
Cute bike.
Never seen one in the UK
😎👍😎
Had a 79 gt80 new. Put so many hours and miles on it.
I know man, we rode them into the ground. Kids!
What is torque induction?
That is what Yamaha called the reed valve induction that started with the 72-model year.
Does anyone know what type of transmission oil does this use? I have a CT1 and looking for that info
regular motorcycle oil. 10-30w stay away from car oil as a lot of it has friction modifiers that affect the clutch (making it slip) folks use rotella diesel oil too.
Motorcycle oil is correct! Although the "car oil" will work for a time, it does not have the proper additives for use with the wet clutches that these bikes have. I run into this problem a lot with older quads as well as these older bikes. I have 8 of these bikes myself and thoroughly enjoy riding and wrenching on them. ❤❤🙂🙂👍👍@MegaWildweasel
Just 10/30 motor oil. That is what the manual calls for. Remember at that time synthetic oil was just starting to come out. So, most motor oil back then was petroleum-based oil. I have had many folks come into the shop with slipping clutches, when asked if they were using synthetic or semi-synthetic oil, all that were, a change to petroleum-based oil is all it took to fix the problem. In the 60s, and 70s these clutches were designed for regular car motor oil. Regular Car motor oil (petroleum based) from Napa in 10/30 is all I use in these older bikes.
Here!
I had a gt60.
I would love to find a 73 like that one for my collection.
Everything is so tiny, almost need tweezers…lol
Yes, this is a fun bike. I bet you will find one. Minibikes are really hard to find these days. LOL tweezers,
Here
im last in line,sorry to be late.
It’s a 73
Yep 73, in the video description I said 73, in the video I did said 76. Woops
The best made bike, with the worse problem. funny 🤔😉
I think your right Richard. Hate to see the problem, but I think it's going to be fun getting it going again.