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Discussion Starter · #1 ·
Thanks for reading!:)
I just bought a Yamaha Enduro, 1976 80cc 2-stroke, that seems to have been maintained by a super clumsy dood. All the screws are stripped so I want to know exactly what the problem is before pulling it apart more.
Here's what I know: The spark is fine, and so is the device that powers it, it tests OK. The carburator seems OK I cleaned it and the fuel tank.
The problem seems to be after the carb- the bike usually doesn't start unless i drop some fuel directly into the cylinder, I think fuel is not reaching the engine successfully. It ran well at first, then suddenly sputtered out. Then it always did that whenever I got it to burn, and recently it hasn't burned anything but gas dumped directly into the cylinder. I suspect it might be some valve that is clogged with rust dust since the fuel tank was very rusty and the fuel was contaminated with rust. (tank has been flushed and scrubbed)
Does anyone out there know about these bikes or have general advice for this type of problem on an old school two stroke? It would be so appreciated!
This should be simple but I'm way ignorant and can't afford to experiment much at risk of ruining the ruined screws more.
 

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If the tank is rusty you need to clean it extremely well using electrolysis, or some chemical kit made for cleaning tanks. Most likely you have something stuck in the carbs. I would also add a small fuel filter to keep rust and dirt out of the carbs. Could be a stuck float, or just something lodged in a jet. Well it fire if you spray a little starting fluid in the carb? Good luck getting it running.
 

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Discussion Starter · #3 ·
Hey kev, thank you for your advice. So far I've only scrubbed and rinsed the tank using steel wool and more gas. The type of electrolysis that I am familiar with is for coating metals with another type of metal that deposits from solution. (Cu plating for example) Is this what you meant or is there another method that removes the Iron Oxide it's self?
Applying gas to the carburator is not resulting in fire, applying gas to the cylinder it's self is. I opened the engine more and the path between the end of the carb and the cylinder does not appear to be obstructed.
 

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Try a search on here for a cleaning gas tanks. There are a couple of really good post for electrolysis method using a battery charger. The electrolysis will remove all the nasty stuff from the inside of your tank. I have never done it myself but would try it after reading about it on here. I have also had good look with the POR-15 tank kits. Good Luck!

Kev
 
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