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BLAKE needs Sporty help, too....!

1585 Views 7 Replies 4 Participants Last post by  fastsporty
My bro's '77 Sporty has been running like a champ, but he called me over tonight in a panic. Earlier, the bike had been a bitch to start, then apparently shot about a quart of oil outta the vent tube off the right side of the generator housing and wouldn't rev, then the oil pressure light came on. He killed it and called me, and after checking the oil level we fired it back up - started right up, and at idle there was no more oil outta the vent tube, but the oil light stayed on steady so I killed it until we can replace the light with a real gauge.

Anybody got any thoughts? Oil pump? Figured the oil outta the vent tube might be a tell-tale symptom for somebody who knows these things.

Any help would be appreciated.
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I've seen scooters puke a lot of oil out of the vent tubes when they've been setting for a while, usually a couple of weeks or longer. Since the cases are lower than the oil tank the oil gravity feeds past the check ball and into the lower end. When you crank the engine the scavenger side of the oil pump can't pump all of the oil back into the tank quick enough and the oil takes the path of least resistance-out the breather. This is a one time deal until the bike sets again. This wouldn't have anything to do with the oil light staying on though. Check the pressure with a gauge. If there's oil in the tank and the gauge stays on zero, the first thing to check is the oil pump. If it picked up trash and locked up, it can strip the key in the drive gear on the pressure side of the pump.
You could also check the pump by pulling the return line off of the oil tank. Crank the engine an if everything's working it'll pump oil out of the line. No oil coming out of the line--check the pump.
Larry T
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fastsporty said:
Ok larry this is where I get confused... He said it was hard to start and then it ran rough and wouldn't rev, which is a sign that the plugs could be fouled. Which is why I first went with the gas in the oil. But then he has the oil light issue, what he sheared the pin and then it some how caught again? giving it oil pressure. then he said it puked out a 'quart of oil ' but then when checked it was fine. even if it wasn't a quart of oil you still would of noticed the oil being lower.
Who knows? like I said Blake check the oil to see if it smells like gas, when you put a gauge on it be prepared that the pressure is real low at idle like sometimes less than 3 lbs especialy if you use that little plug between the lifters, see that you are getting return oil in the tank, another little trick i learned is to use a clear piece of tubing to go back in your return than you can see the oil flow. Also listen to see if your oil pump is making any weird noise or slipping, not easy but try to check it out anyway.
let us know
I was just throwing out some more stuff to check. It's kinda hard troubleshooting a problem over the internet (or telephone for that matter). Like, does the engine turn over ok and not start or does the engine turn slow or act like it's locking up (hydraulic)? You made a real good point about checking for gas in the oil. What I've seen on the oil pressure gauge deal, sometimes scooters have VERY low oil pressure at idle when they're warmed up, but usually come up off the peg when the engine is cold.
I don't really understand what you're talking about on the no oil pressure then having oil pressure again deal.
Back to the shop. I just got a customers flywheel assembly back from Truett and Osborn a couple of days ago and he wants his bike running for some reason.
Larry T
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