'74 TY250 Autolube Questions

Should I use the auto lube or disable it and mix my own? What would that ratio be BTW? My 01 montesa runs 77:1...not sure about other older bikes.

If I do disable it, what steps would I have to take? I've never seen one before but while tearing the bike apart I noticed the reservoir on the left side of the air intake, the two throttle cables and the oil lines and got curious.

Just wondering of these are bulletproof or not worth the risk.


They are bullet proof if set up correctly. They use less oil, enable use of straight fuel in the tank and foul fewer plugs. That all said, I often have found them mis-adjusted, often pumping close to twice the amount of oil spec'd for. Yamaha would set them rich at the factory to ensure proper break-in. First service entialed setting them to correct spec. This was rarely done. Been a while for me and I'd hate to suggest settings and be mistaken. The only thing you want to watch is the oil you use. Nothing worse than old castor oil clogging a line.

Many of the old injector systems would put the oil in where it lubed a bearing, so removal wasn't a good idea if it's obvious it's plumbed like that. Adjust it and run injector oil (not premix only oil). There's usually a dot or line on the pump arm that lines up with another on the pump body. Some are set up to line up at full throttle, others at no throttle but with the cable freeplay taken up. If theirs two marks close to each other, it's min-max. Set it up with the lines then run it keeping real close track of fuel and oil usuage for a couple tanks. Do the math to find the usage ratio, adjust if needed, 50:1 is a good number because it's an average. It'll pump more or less than that depending on rpms and throttle position.

Edited by highmarker

Thanks for the info both of you.

iv done a few,,

if your going to ride the bike,..dissable it..remember how high in Alt we live in.

wonder why so many older yamaha,s are locked up here???

if your not going to ride alot and only restore, then clean it fresh up the hoses, and be done.

to dissable.

remove the throttle, cables, ect, put them in a box. dont break anything removing it.

remove the shaft for the pump, clean the hole with mineral spirits, and fill with red RTV, gasket material. let sit for 24hrs.

remove the carb..its not a Mikuni..

go to Ebay, and find a 28 or 32MM Mikuni with cable, and throttle, in good shape, usually 100.00 gets them, make sure its the same type hook up and dems as the one you removed.

when it gets here.

clean it inspect it, and install.

clean the fuel tank, add Mix fuel of your favorite 2 stroke oil.

fire the bike up, and adjust jetting as you need for were you live.

chances are youll have to lean it a bit,

remove the oil tank and all the the oil enjection parts put them safely in a box, if you ever sell the bike, the new owner will likely want this.

heres the big issues with the Yamalube set up.

the oil tends to gel and get thick in the cold, or lumps up, clogging the lines, not letting the oil get to the pump, ruining said pump, and ruining the crank as well.

the oil enjection 2 strokes, are jetted very rich for a reason, look at how larget the main jet hole is on the stock carb, its huge..

try and find jets for that carb,,,aint gonna happen, youll only get frustrated in the long run, its easier to replace the carb, cable, and throttle with a working example.

iv done more then a few,,and these are hard lessons learned.

iv done a few,,

if your going to ride the bike,..dissable it..remember how high in Alt we live in..

Thanks very much! Great info. I'll remove it and put it in a box...or sell it. I'm planning on riding the heck out of it...so your idea sounds like the one I'm going with. I was worried that if the pump failed i'd have issues. I'd prefer to mix my own anyway.

Thanks for the info!

i would disable it too they suck:thumbsup:its not worth a top end if it goes bad,i did it in my bass boat with a 200hp johnson just because of the fact that theres no way of telling if its working unless of course it blows up and a top end in a boat is far more$$$$$$$$$ i would leave the pump in though,those bikes are designed to run a 27mm carb anything bigger wil not jive with the pipe etc which is designed specifically for trials

without lube, the pump will fail, and lock up, they need to be removed, the pump shaft removed, and the holes plugged, both on the crank, and the side cover.

water, dirt ect, will get in the crank, and youll be rebuilding the bottom end.

Kawasaki KT has a better deal, and its easier to dissable.

i rode a KT to 3 nat, championships,never gave me a bit of trouble, and i was pretty mean to it.

id bet the bike still runs, i sold it via Ebay a few years ago, and regret it.

ok im with you on plugging the holes thats common sense,but i thought the pump engages when the throttle is turned....no?

Yamaha TY,s have a shaft that runs off the crank, that works the pump, the cable just opens a valve inside the pump to allow oil to pass.

if you have no oil in the pump,the shaft will have no lube, it will stop.

only Yamaha thought this was a great idea...lol.

Kawasaki, Suzuki, Bridgstone, and Can Am all used a variation of oil ejection, some better then others.

Kawasaki KT,s had the best, if it failed it only ate the top end, if the others, failed, it ate the crank bearings and the piston...

some of the Kawasaki and Suzukis mounted the carb right on the crank side...

and gave it a cool name..added some ponies...lol..maybe..

but reed valves, and good jetting beet that hands down..

the single shock TY,s were an upgrade, mix in the tank, with a reedvalve..

Why are we guessing here? Bob Ginder is the TY and KT guru and can answer all your questions at B&J Racing. He also has block-off plates at a good price and KNOWS if you cannot take off pump....he's not guessing! I do know he runs 50:1 premix. That's what he wants me to run in the KT250 he just built for me. He also can jet your bike so that it is crisp right off the bottom FOR YOUR ALTITUDE and sells complete kits to do it. No guessing....put in jets and needles,some of which are specially machined and ride it and win. His phone is 1-615-789-5956, Dickson, TN Central TZ.

who said i was guessing,???

lived at 5400 feet all my life, and been at this for 30 year, the guess work is long gone for me.

im sure the guy is first rate, but he wouldnt have to ship it, just bring it by my shop, and get it done.

cant get more simple then that..

Sorry Huskychuck. I'll get off your toes now.....

lol...FYI: one of the Hosts here on TT, is an AWESOME carb and jetting guy,

Eddie,, his buddies call him Fast eddie...fastest guy on a Hodaka...lol

he,s local, will gladly help with any Colorado alt, jetting questions...

heck of a guy as well.

lol...FYI: one of the Hosts here on TT, is an AWESOME carb and jetting guy,

Eddie,, his buddies call him Fast eddie...fastest guy on a Hodaka...lol

he,s local, will gladly help with any Colorado alt, jetting questions...

heck of a guy as well.

Since we're on the subject of jetting, I am wondering what the ideal jets and needle position would be for my 74 ty250...I usually ride at elevation...my house is at 7400, and I ride between 5k and 9k feet.

My needle is currently clipped in the third position from the top (5 positions to choose from).

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