Whats wrong with this little yamaha motor?
 

I have this little 1971 Yamaha Mini enduro 60 that was my first bike. I havent ridden it in probably 4 years and I decided i would see if it would start and well it just started running this blue green oily/gassy smelling substance out the side of the motor(see pics). What is wrong with and how hard would it be to fix or rebuild this motor. Might just build the whole bike i have all the parts.

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looks like leaking 2 stroke oil to me...

Where from up inside there I wonder. I know we have never been in the motor and well when i was riding it i was so young that i didnt mess with the oil at all. I do know that this bike has an oil tank on the other side and you dont have to mix the gas and oil like you do with some 2 strokes.

It's been a long time since my Yamaha 360 days...early 70's. But I'd suggest removing the seperate oil tank, check out the direct oil system. Looks to me like a leaky seal in that...

Thanks i will try that. Anything up in there that all that oil will have hurt?

My best "initial"guess at this point would be a leaking float needle (due to old shiit gas) which allowed the crankcase to fill with gas/oil mix which then leaked through the magneto side crankshaft seal. "Might" be able to simply drain the gas tank, clean the carb, remove the excess oil from the mag cover.

A leaking crank seal on a 2-stroke is usually bad, but on that little Yamaha, you might be OK.


EDIT: PWD72s is probably right, assuming the leaking oil does not smell like gas.

Not that I know of...hell, it may have helped your engine as a corrosion prevention

Dunno where, but you may try to find at least an exploded parts diagram before you dig in.

http://www.bikebandit.com/houseofmotorcycles/yamaha-motorcycle-jt1-1971/o/m7330
Like that? I have it off and apart already. I have pics to upload later.

Clean it up,empty any remaining oil from the tank and run it on pre-mix.

My dad has suggested that. If resealing this pump doesn't work that is plan b. Any suggestions on what mix to run?

50-1 is standard

My chain saw likes 4 oz. to a gallon....but maybe a bike should be more oil? Just guesswork here.

Man, I wish computers were around when I was riding dirt bikes...those exploded diagrams are great!

Good luck!

first yer sitting on quite a collectible bike. second i used to have posters of that damn bike plastered all over my room as a kid. third i almost got juan for my birthday until some idiot smacked a tree, killing himself, not a block away from our cabin in pinetop arizona about a month before my b-day. im still pissed off at that lil bastid for screwing up my life by killing himself! man just think of all the chicks i could have had if i had that bike back then. i probably should sue that kid for a lifetime of misery i had all because i had to wait until i was 18 to buy a bike and even then my folks were pissed and mentioned that moron in their warnings to me about dirt bikes.


anyway if its like all the bikes i get to freeking deal with that are barnrats.............its more than likely the crank seals took a crap and are leaking thru. this is real common on bikes from any country that sit around for years and the seals just rot away from lack of TLC.

when we store a concours bike for display............no oil/no gas/no fluids. that way seals are new, stay new and if bike is to be used we just put fluids back in and off they go into the wind.

any lil bike any mfg 3 wheeler/quad are worth their weight in gold nowadaze. look at what honda mini trail 50/70's go for from the 1970's.

Is it 2 stroke oil or transmission gear oil? You should be able to tell the difference pretty easily, gear oil will have more of a sulfur smell and will be much thicker.

On the pre-mix I'd run 40 to 1. It'll smoke a little at idle but any leaner would be hard on the top end.

BTW, When I was a little kid I had a poster of that bike on my wall. I dreamed about it, I wanted it sooooo bad. It was all I could think of. Unfortunately my parents didn't have discretionary spending for that kind of thing, I didn't taste fast food until I was almost a teenager.

I finally got a used YZ 125 years later, lots of mowing lawns, paper routes, and saving up birthday checks from grandma. IIRC I paid $110 for it. Mucho bucks back then.

It's green, it's 2-stoke oil. If it's a leaking injection circuit, you should be able to fix it pretty easily. Keep in mind that if it's the oil circuit, you may not be getting lube to the crank and cylinder, so I wouldn't run it that way.
That old a bike may have run 32:1...

WIth oil pooled around the the stator like that, it might be the crank seal, which would cause the engine to run lean...
That looks like an awful lot, unless it's been going on for a long time.

Nope just started that and it hasnt been run at all that way.

When you were playing with it, did the oil leak appear after trying to kick start it? If so, the crank seal probably was stuck to the crank, and when the engine was turned over, the seal was torn.

A bike that old would not have been running 50:1 oil mix.
I mix 32:1 in my 74 Yamaha DT360.

I have owned 2-strokes nearly my entire life. I have used many different brands (Klotz, Golden Spectro, Yamalube etc) of 2-stroke oil over the years, especially during my serious MX racing years.

Several years ago after running my previous favorite Yamalube for quite some time in my Ultralight, some local ultralight guys convinced to start using Amsoil synthetic as they had been running it for years, it is relatively inexpensive, it is sold in many stores, it is mixed 100/1 which means you have to carry less of it and most importantly to me, several of these guys had ultralight engines with 300+ hours on them without being rebuilt.

Since I made the switch (8-10 years ago), I have used it exclusively in EVERY 2-stroke I own with no failures. (old and newer motocross bikes, snowmobiles, chain saws, weed eaters, ultralights etc). I simply dump one of these little bottles into 4-5 gallons of gas and forget about it. I think my ultralight engine calls for a 40:1 mix and various dirt bikes and power equipment all have different requirements, but the synthetic Amsoil mixed 80-100:1 works great in all of them and trust me, I run my equipment very hard. I typically run my ultralight at 6500-6800 rpm and on occasion all the way up to 8000 rpm. I have over 200 hrs on the engine and all of the time other than taxiing has been at well above 6000 rpm. My current MX play bike is an old 125, so when it gets ridden, the throttle remains pinned most of the time.

Many companies make good 2-stroke oil, but when I find a product that works and it proves itself over time to me first hand, I stick with it.

http://forums.pelicanparts.com/uploa...1220735304.jpg

Hmmm, a JT-1....I got one running last year and sold it for my neighbor lady that had it since she was a kid. For value, I sold in on Craigslist in one hour for $700.

U have a strange situation. I'm leaning toward a left crank seal also (Trans is separate and the oil wouldn't leak out there) . BUT, all that should be in the crankcase should be a fuel/oil mix as the oil injection pump injects oil into the carb area, which is on the right side of the engine on this model. To have a puddle of clean, undiluted oil, I would carefully inspect the line from the oil tank to the oil pump. If the line or pump is leaking, it would not be coming out the area of the stator.

If it is a crank seal, don't run the engine long, as it will suck air, run lean and lead to seizure.

To repair a crank seal is a lot of work, complete disassembly of engine/trans

Hmm bob you wanna buy a JT-1? You know lots about them apparently. Id take 500.

Thax for the offer, but gotta pass....I'm downsizing. I'm down to 14 bikes from having 22 a year ago.....Good luck...

crank seal, more than likely.

Ok guys.... I don't have time to fix this mess.... Who wants to buy it? I need space in my Garage for the '24s project...

And money in my wallet.... Make me an offer... She's all there... I've got a complete front fender to go with it.

$300........U deliver to Lake Cle Elum, stay in my cabin looking over the lake as long as you like - like a free vacation.......Deal?

Sounds like a money loosing proposition to me... Plus in the time it'd take me to get up there and back.... I could fix it....

well more than likely fuel/oil filled up bowl and leaked down into case.

crank seals are usual suspects that have sat for awhile. butttttt..............dont be afeared. clean the carb. drain bottom end oil then refill. add gas and see if ya have spark. if so proceed with starting.


remember gas/spark/air without one yer screwed.



those stoopid ass mini bikes are threw the ROOF spendy now totally restored. be ready to grab yer ankles on what parts prices are.


but they are fun and you will be stylin next PCA club race buzzing thru the pits. you might quite possibly get ALL THE CHICKS riding that thang.



our suzuki DS-80 oil injected is faster than yours and has totally kool replica wanna be carbon fiber steekers on it! wanna race? and it has a UNI steecker on it!

I might be interested! I will even drive up and get it. Lets talk. $500 is a little steep though considering time/money to be invested in getting her going...

5 bills is DIRT CHEAP for ANY MINI BIKE FROM the BIG FOUR!



go price out a restored mini trail 50 or trail 70 and POO YERSELF!




these lil poo bikes are GOING UP not going DOWN!



the older it is and with a COCOURS RESTO on it, you will be the KOOLEST KAT AROUND and YOU WILL GET ALL THE CHICKS!



we ride a mini trail 50 circa 1969 and a 1993 suzuki DS 80 oil injected and we IZ WAYYYYYYYYYYYYYYYY KOOL!

$500 is just a number I pulled outta my arse.... I'll talk to my pops and get back with you on a price...

Mike since its you and we like ya...

Dad says take 300 and get it the hell out of my garage...

RUN LIKE A MOFO! thats a screaming deal! and I APPROVE!



hell if ya get totally pissed off, drink a case of beer and tear every single damn part off of it and PART IT OUT ON CHEESE-BAY and QUADRUPLE YER MOOLA!



i have amigos that do this for a LIVING and they are VERY WEALTHY tearing apart stoopid ass fairly limited production dirty bikes and parting them out on evil bay.


dont laugh these lil poos get el supremo bucks when restored concours.



mini trails and trail 70's highly COVETED by pilots as they can throw them in plane and buzz around at their destination picking up CHICKS!



if yer REALLY KOOL add streamers to handle bars i can gurannnteee you will be laid in an hour!

It was a really fun bike back when I was riding it... You could always mix the gas and tune the carb and not mess with the oiling system. We can pretty much trace ownership all the way back to new... It hasn't been out of the same 10mi circle as far as we can tell...

While they have risen in value and you might find a buyer willing to pay $1500 or so for a nice restoration of some of the more desirable minis, when you tally up the time, NOS parts, paint, chrome, seat covers etc they really are not money making projects unless you get them dirt cheap sitting in a barn and then simply part them out on Ebay.

I love minis, but from a financial standpoint it is probably not worth the effort unless you are restoring it as an heirloom or because it is the bike you owned or dreamed about owning as a kid (BTDT with a few Honda 50s).

i can attest to this in spades!


1) ya have to find buyer that has to have it no matter what

2) after restoring it it will be so damn nice YOU wont even want to ride it let alone any of yer drunk meathead friends.

3) it will become OFF LIMITS to yer kids its so nice


4) it will sit and lanquish again for another 20 years


5) it will go in somejuans museum


6) or ya ride the piss out of it and depreciate it all over agin like us.

See.... I'm not into concourse restorations...

B/c I tend to ride or drive the piss out of things... So I get them nice... Use them like they were meant to and not worry about the occasional scuff...

Neither was I at your age..... Oh how I wish I had kept my '76 KX250, my '72 240Z, my '72 Mustang, my '70 CB350, nearly all of my CR250's, my ATC90, my XR75, my CT70, my Z50 etc. When I was young I lusted after new latest/greatest stuff... now as I get older, I lust after the older/simpler stuff from my youth.

Back in the day they were just broken down clunkers that I had no money/desire/skills to fix/restore. I typically either junked them or sold them for a couple weeks worth of beer/gas money. I truly hate myself for getting rid of many of them as my greatest enjoyment in life now stems from restoring/repairing old stuff like this.

When I was young I lusted after new latest/greatest stuff... now as I get older, I lust after the older/simpler stuff from my youth. Same holds true for my dad... he was only ever interested in brand new cars/toys.... Now he appreciates more the things he lusted for in his youth like the Cushman I restored for him. ;)



http://forums.pelicanparts.com/uploa...1276707934.jpg

thats OBSCENELY BUENO!

I want this little bike gone....


One of you guys interested in buying? Its garage fresh, been sitting for ~8yrs now....