rev. victor Posted October 17, 2006 Report Share Posted October 17, 2006 Just picked up a TY80 for my nephew to ride. Bike had been sitting but is mostly all there and after a quick carb cleaning it started right up. I am curious about the oil pump. Do most people run the oil pump, or is it removed and the bike run on premix? I know on my old DS7 and RDs we'd drop the pump for track use. Thoughts and suggestions are appreciated. Quote Link to comment Share on other sites More sharing options...
sting32 Posted October 17, 2006 Report Share Posted October 17, 2006 Just picked up a TY80 for my nephew to ride. Bike had been sitting but is mostly all there and after a quick carb cleaning it started right up. I am curious about the oil pump. Do most people run the oil pump, or is it removed and the bike run on premix? I know on my old DS7 and RDs we'd drop the pump for track use. Thoughts and suggestions are appreciated. My old schooler's opinion (back when these were not as old as they are now) was to remove the oil pump, mix the fuel remove any doubt or chances that oil was not getting to the engine. Plus, If for no other reason, when we did this back in '74, I then also used the same can as my dad and everyone else at the trials. No more ooops wrong can for his bike ordeals when we did this. But nowdays the watercooled bikes run just fine with 80:1 (full synthetic) not sure I call that enough for the air cooled machines, especially if like me when I was younger I might go "flat Trackin" down the trails on my ty because the other kids had enduro's or MX's. My son's ty80 already had the pump off but he had his own can of gas with 32:1 in it, NON synthetic, (if you use 100% synthetic do 50:1). Quote Link to comment Share on other sites More sharing options...
kevin j Posted October 18, 2006 Report Share Posted October 18, 2006 I took them off, to be sure of lubrication and also made a lighter throttle spring. If you decide to go premix, the pump must be removed, not just disconnected. If remove the cable it will still pump some minimum oil amount as though the pump is at idle. Then, at actual engine idle, it gets 2x the normal oil: oil through pump, + oil in premix. That can really mess up the exhaust over time. To pull the pump, need to split the case as I recall. Can't just remove it from the outside. Then make an aluminum plate to blank off the hole. Plug oil lines on carb/engine and make a new one piece throttle cable without the splitter box. I used universal outer housing, but smaller than normal bicycle brake cable for the inner core. Made the throttle a lot softer for small hands. as I recall, I ran autolube until the first engine service, then removed the pumps when the engine was apart anyway. th\ese were old TY, that my kids rode in 1995 to 2000 or so. kcj Quote Link to comment Share on other sites More sharing options...
vintagecota Posted October 19, 2006 Report Share Posted October 19, 2006 I'm not up on two-stroke oil injection, but wouldn't it work to just empty the oil reservoir and use premix? Maybe plug the line at the intake? Are you overcomplicating, or am I oversimplifying? VintageCota Quote Link to comment Share on other sites More sharing options...
kevin j Posted October 19, 2006 Report Share Posted October 19, 2006 there is probably a way to do that by filling the pump and hooking lines around in a circle to keep some lube in there. Barring that, by the way the pump is built, I think it would eventually seize up and cause damage. The pump is a reciprocating piston, stroke varied by throttle cable position, but driven by engine speed. So the amount of oil injected varies by engine speed + throttle load. Great concept, great for street bikes. just a pain when mixed in with a bunch of premix motorcycles. Anyway, I would expect the piston to eventually seize, then the increased force to move piston would cause the plasttic gear to fail. That is inside where bits can cause other damage. Maybe disconnecting the cables, plug off the ports at carb/intake to cylinder, keeping some oil in the tank, but taking pump output line and connecting it back to the suction line (a brass tee fitting) would be an easy way to accomplish this. I never thought of that before this writing, but I think it could work. That said, I have seen several there the cable and lines are disonnected, but pump still running. Have no idea how long they ran before I saw them, but I would not go that route. kcj Quote Link to comment Share on other sites More sharing options...
rev. victor Posted October 19, 2006 Author Report Share Posted October 19, 2006 Thanks for the input. For the time being I'll test the pump per the manual and monitor it. If it appears to be suspect I'll examine removal. The system works well on my DS7 of that vintage but wasn't sure if they normally yanked off on off-road machines. I'm surprised that Yamaha went to the trouble on a youth machine. Quote Link to comment Share on other sites More sharing options...
kevin j Posted October 20, 2006 Report Share Posted October 20, 2006 I had a DS7, gold and black 72, bought new for the wife in 1973. Eventually, I converted to RD350 cylinders and 6 speed gearset. quite the screamer (for those days at least) difficult to ride well, and very rewarding when everything was right. It currently sits in the ex wifes pole barn unused for 18 years. I'd like to get it and continue the project, disc front end would be next. Easily available on ebay. Fun bike, many long miles on it. kcj Quote Link to comment Share on other sites More sharing options...
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