bought a 79 jr50 for $100 and it runs

[79jr50]

i just got this little bike for my little brother, it runs and drives and shifts fine, only one problem, it does not have a air filter, so i will be getting one shortly, when i turn the bike on it wil stay on only if i pull back the throttle, it wont stay on otherwise, can this be because of the air filter? also what kind of gas should i run, and how would i go about mixing the oil and fuel? is there anyway to get the suspension higher and stiffer, hes a bigger kid. any info will be greatly appreciated thank you.

 

[motorman]

i just got this little bike for my little brother, it runs and drives and shifts fine, only one problem, it does not have a air filter, so i will be getting one shortly, when i turn the bike on it wil stay on only if i pull back the throttle, it wont stay on otherwise, can this be because of the air filter? also what kind of gas should i run, and how would i go about mixing the oil and fuel? is there anyway to get the suspension higher and stiffer, hes a bigger kid. any info will be greatly appreciated thank you.

Welcome to miniriders mate.

Turn the idle screw up on the carby to fix the stalling issues. It will be running lean with the filter off. May need to play around with the mixture screw once you do get a filter.

Can run any gas. I would reccommend 95 and above though. Mix the oil with the fuel at a ratio of somewhere between 32:1 and 40:1.

For the suspension, should be able to lift the forks up or down in the triple clamps. That will adjust the front. For the back, should be able to compress the shock slightly. Have a look and you will see where it can be adjusted if it can at all.

 

[foolsp33d]

JR50.. two stroke!? the throttle sounds either like an adjustment issue or it may need a new cable. You can try starting it without the airfilter, but try not to ride it as you will suck dirt n crap into the engine.. staring it without the filter will determine if its going to make a difference to the throttle cable, which Might just need a lube!? Fuel wise, im not sure what the mix ratio is or if its a seperate oil/ fuel.. but unleaded and a DECENT 2 stroke mix have you tried a google search for user manuals/factory manuals etc? What is the rear suspension setup? If its like a z50 and twin sprund, you could look at getting some xr80 or similar shocks.. they may require modding to fit.. I dare say the front end could be modded accordingly to suit a decent(crf50 maybe) fork and wheel..

In the mean time.. Throw up some pics

 

[foolsp33d]

JR50.. two stroke!? the throttle sounds either like an adjustment issue or it may need a new cable. You can try starting it without the airfilter, but try not to ride it as you will suck dirt n crap into the engine.. staring it without the filter will determine if its going to make a difference to the throttle cable, which Might just need a lube!? Fuel wise, im not sure what the mix ratio is or if its a seperate oil/ fuel.. but unleaded and a DECENT 2 stroke mix have you tried a google search for user manuals/factory manuals etc? What is the rear suspension setup? If its like a z50 and twin sprund, you could look at getting some xr80 or similar shocks.. they may require modding to fit.. I dare say the front end could be modded accordingly to suit a decent(crf50 maybe) fork and wheel..

In the mean time.. Throw up some pics

 

[79jr50]

i see two screws on the carby which one is it?, i dont know much about bikes not at all, i work at a car garage so i figured if i can do everything on a car, working on a bike shouldnt be too hard. and how does the 32:1 and 40:1 thing work, i just added gas to it today and it did not want to start after that, should i have mixed in the oil?? did i mess something up? thank you for the quick reply

 

[motorman]

i see two screws on the carby which one is it?, i dont know much about bikes not at all, i work at a car garage so i figured if i can do everything on a car, working on a bike shouldnt be too hard. and how does the 32:1 and 40:1 thing work, i just added gas to it today and it did not want to start after that, should i have mixed in the oil?? did i mess something up? thank you for the quick reply

One will be fuel mixture and 1 will be idle. Start the bike and turn one of them and if the revs go up or down, that's the idle. Take note of what position it's in just in case it's the wrong one (I can never remember which is which).

32:1 is a ratio. Basically for you, I would go 500ml of good 2 stroke oil as fools said to 20 litres of fuel. That would be 40:1. Should do the job. Yes you should have mixed the oil first. If you just stuck fuel in with no oil, you may have damaged the motor. Drain the tank and mix some new stuff up.

 

[79jr50]

it has a gallon tank, how much oil would i need to put in, i will go take some pics of it right now, its a beast machine from 79 haha

 

[TyD]

The idle screw is normally the one with the spring underneath it...

Get yourself some Motul 800 factory race oil and mix 30mls of oil to 1 litre of fuel..

 

[79jr50]

here are some pics

 

[motorman]

it has a gallon tank, how much oil would i need to put in, i will go take some pics of it right now, its a beast machine from 79 haha

Mix it in a fuel container first

 

[79jr50]

supposivly its an oil injected bike???

 

[motorman]

supposivly its an oil injected bike???

Is there a seperate filler for oil?

I doubt it would be injected. Too old. Don't quote me on that though.

 

[79jr50]

it looks like it, there is a cap right by the kick start, im guessing thtas for the oil? if so that might have just saved me a bunch of trouble

 

[motorman]

it looks like it, there is a cap right by the kick start, im guessing thtas for the oil? if so that might have just saved me a bunch of trouble

That would be the gear box oil mate.

What's in the white container thing towards the back of the bike?

 

[79jr50]

its empty i have absolutly no idea, i dont know anything about dirt bikes i figured with $100 you cant go wrong, so what do i do now that i poured in the fuel and it wont start, should i drain it and add about 125ml of oil to a gallon tank, which is around 3.8l

 

[motorman]

its empty i have absolutly no idea, i dont know anything about dirt bikes i figured with $100 you cant go wrong, so what do i do now that i poured in the fuel and it wont start, should i drain it and add about 125ml of oil to a gallon tank, which is around 3.8l

By the sounds of it mate you might be better getting a mate that knows a bit about bikes to have a look.

I doubt it is oil injected. Better off mixing it anyway. That would be the first step. That's not the cause of your problems though with idling.

 

[79jr50]

i know its not the cause of the idleing, i just want to get it started again, it just ran i rode it today just for a little test drive, i guess ill just dump the fuel and mix it up and see if it will start then, it never started first kick, it always took some time, im hopin to get it running again, the white container looks as if its going to the gear box or around there, i wish i could find a repair manual online or something...hmm gotta keep looking i guess

 

[79jr50]

the white thing is the oil tank, does that mean gear oil or just reg oil, i found it at this website, have a look 1979 Suzuki JR50N OEM Parts, 1979 Suzuki JR50N OEM Motorcycle Parts - BikeBandit.com

 

[motorman]

the white thing is the oil tank, does that mean gear oil or just reg oil, i found it at this website, have a look 1979 Suzuki JR50N OEM Parts, 1979 Suzuki JR50N OEM Motorcycle Parts - BikeBandit.com

Looks like it is injected then. Just put some oil in and your set. No mixing required.

 

[roost666]

pretty sure there is a reservoir you fill with oil, just fill the tank with fuel and it mix's itself while riding.....but the setup in the pics looks weird so im not to sure.