A lesson I learned the hard way is to verify that the oil is getting into the cylinder after a bore job on bikes that inject it directly into the cylinder. The DT250 was a runner so I knew the pump was working; I didn't recheck it. I just ran it for a while on my IV tank with premix to get the oil moving; then filled the tank with regular gas and proceeded to ruin a new bore job.The hole in the cylinder wall was completely plugged. I should have done more checking but I was new to oil pumps and everyone said they were really reliable. I now know better.
Yes, that is a good lesson Jack, hope that wasn't the cylinder I bored for you. I do always check the oil port. Blow them out with compressed air after removal from the ultrasonic cleaner. I have only seen maybe two oil pumps that failed, both were run dry. Very reliable part.
I guess I just read your @ different. I normally see it as oldguys oldbikes, but this time I saw it oldguy soldbikes, without the space between words. Something happening in my brain, I think. I think you told me about your travel channel once. Take care buddy.
Many people will tell you that the AutoLube pumps are dangerous and just to run premix. I just laugh at them and ask them if they also run premix in their 4-stroke vehicles as well, because if that oil pump fails you are just as screwed. Also, do not underestimate the fact that the automatic system delivers the correct amount of oil every time. It only takes one time messing up your premix numbers to ruin the bike, people think of the failure of the pump to run but they do not think of their own failure to add the correct amount of oil to gas when making the mix. Lastly, as the AutoLube pump is controlled by RPM and throttle position, it delivers a leaner mixture (less oil) at low RPMs. This prevents fouled plugs, saves oil, and saves wear at full throttle. Premix is ideal at a single RPM, and it shows in excessive oil use and smoke at low RPMs.
You absolutely will not get an argument from me on oil pumps. I have been working with them for over 50 years and I have only seen 2 pumps that went out. Both were run dry of oil in the tank. They are the most reliable part of the motorcycle.
Thanks again for clear and concise info Watching this reminded me of the old president mix days with Castrol. Smelt it watching the whole video The Husky guys around here always burned it,great smell
Hello Dale, I really enjoyed that little video. thats a lovely little 125 it sound sweet I do like the sound of a twin engine. I used to own a 1974 RD 125 twin When I used to synchronise the carbs I used a mirror held behind the carbs. The throttle sliders had a little dot on them I did it so as the top of the dot touched the top of the venturi. Ive never seen it done the way you did with your cardboard strips. its a good way something I will try in the future. see you again on the next video brian
Hey Brian, yes, a lot of the Yamahas had that dot, makes things easier, the YL2C that I did a couple months back had it and was adjusted that way, even though it was not a twin. The Suzuki triples also have it you align it to the access port, easy peasy.
I would try to get an OEM Factory service manual, I doubt it, but they may still be available from Yamaha, if not they will show up on Ebay from time to time. I am not a fan of aftermarket manuals, although they are sometimes useful.
Great presentation on the proper operation of the oil pump. I had a friend that raced karts back when I had a 90 twin and he talked me into running Klotz in it. Made sure to bleed all the conventional oil out before the synthetic went in.
That is true, I have even heard back in the day that if you used bean oil in your engine and decided to run any other type that your lower end would go out. I always thought that was BS, but I had seen a couple instances of that happening. But it is true that the different oil types do not mix. Get it all out.
Great information Dale! I'll be using it tomorrow on the GT550. I just finished installing a modified extra exhaust set to a 3 into 2 deleting the lower pipes.
Thanks, buddy, on the 550 there are ports on the side of the carb were the slide goes up and down, pull the access plugs out and just line up the divots on the slides with the holes in the carbs, for synchronization. The pipe mod sounds interesting, cleans it up for sure.
The modified exhaust and carb adjustments made a big difference. It sounds and runs alot better. I also ordered a seat, shocks, forks and handle bar for a 79 GS550L to improve the ride and handling.
I find it amazing to see that the oil pump is essentially unchanged from then to what is in my rz350, from the mid 80's. Just doesn't have the little wheel on the back side anymore, and the line spigots are pressed in. But the setup is basically the same.
Well thanks, sometimes I get cleaned up, the blue Ford has been moved out for a bit while working on another vehicle. Its nice to have the elbow room. The Yamaha is not currently for sale but will be sometime in the future.
I will first let it be known on the channel that one is for sale, if it isn't spoken for pretty quickly, it will go on Bring a Trailer. Thanks for your interest.
Excellent video. I rode Yamahas from 1964 to 2019 (I am a Yamaha fanatic) and found the twin cylinder 2-strokes the most fun to ride. My first Yf 50cc did not have autolube but all the other did
Thanks John, it's a SW, (Stewart Warner), I found mine on Ebay a few years back, but I think they are still available new from a place like Summit Racing. I know the rubber tips are, got several from Summit couple years ago. They make flat and tapered to fit different applications.
