kwik129

I own a 1978 Yamaha ET340B sled and am a complete novice. Figuring things out as I go and having fun doing it.
The person who I purchased the sled from said there may be something wrong with the oil pump? He was not using the pump to lubricate the engine, he was pre mixing and it smoked bad. His pre mix was 50:1. So that oil pump was working dry which probably trashed it?
I took the top end apart and found the cylinder wall slightly scratched but the sides of the pistons near the wrist pins were discolored. Going to bore .010 over and put new pistons in.
That brings me back to the oil pump. I can pick one up for $60 but funds are tight. Is there any reason why I could not pre mix for now? If so, what ratio?

Thanks.

kccats

50-1 is a good start point! Was the clutch replaced? Is there 2 cables at the carb? Is there still an oil tank? Is there oil in it? Has it gone down at all?

Badnad

If it was smoking bad then the oiler was probly still working. That is of course the previous owner didnt mix the fuel 10:1 or soemthing like that.
I dont think runnin the oil pump dry would cook a motor, as long as theres sufficient oil in the gas, but im not %100

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94' xlt - runs
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kwik129

To my knowledge the clutch was not replaced. What effect would this have with this situation?But loks like I'm going to pull the clutch so I can check out the oil pump drive assembly. After that I can take the oil pump off the assembly and measure the travel of the "plunger".
Like I said, I fear that the oil pump itself is bad becasue it was run dry for who knows how long. The oil tank, lines, strainer are all there and hooked up.
I have a Clymer manual and it walks me through priming the oil pump. Guess I'll have to go trhough the steps and see if it works.

kccats

If the clutch was changed, then the oil pump could have been out of service! How about the cables?