I have a question about a Yamaha 1200 XLT. How does the oil pump funtion on these engines? Is the cable that is on the front of the pump some sort of metering device? I rebuilt this engine, (with the very capable help of some people on here, and thanks so much again) and when i first ran it i put extra oil in the gas for break-in, however it does'nt seem to use as much oil as i expected from the oil tank. I guess my question is this: will adding oil to the fuel effect how much oil is provided to the carbs from the oil pump?
Thanks for any help anyone can give me on this....
The cable to the oil pump is connected to the troutle, the more troutle you give the more oil the engin needs. Oil in the gas will not effect the oil pump ratio. What you should do is mix some oil and gas to the recomended ratio for a yamaha, then remove some of the oil from the oil res, make mark on the oil tank where the level is. When you fill the gas tank, add the appropriate amount of oil back into the oil tank, same as what you mixed with the gas. When the gas tank is empty the oil level should line up with the mark. If not adjus the cable to use more or less oil. A couple of gas tank should zero it in for you.
Thanks for your reply Big Daddy. Here's what i've done and how i figure this oil consumption, bear with me? I pre-mixed oil for break in. I've burned about 35 gals of fuel as pre-mix. Here is the way i'm figuring this. At 50:1 ratio you use 0.390625oz. of oil per gallon of fuel. At that rate 35 gals.x0.390624 oz. oil = 13.67 oz. oil. Does this sound right to you?
your math is correct. the thing is though that the oil pump is designed to provide certain ratios at different RPMs in the power band. When people switch to premix, they run it at 40:1. In fact, 40:1 is only needed at idle and WOT.
If your oil pump works it will use a LOT less oil than if you premix.
I kept the rpm's at 5000 or less varying them quite a bit and i figure i used about 60- 70 oz of oil burning about 35 gals of gas, this seems about right to me, it just did'nt seem to be using what i guess i thought it would. Are these pumps the type that either work or they don't. The reason i'm asking is it is pumping oil to the carbs, i just did'nt know if it was enough.
Well, it looks as though i'm on the right track with this thing then. I had alot of fun re-building this engine. I got alot of advice from the guys on this forum. You guys are the best, thanks again to you all...