1983 Yamaha Maxim 650 Just got bike a few weeks ago - engine was replaced to I believe a 750 Engine will not turn over - starter engages - all battery and electronic components and fuses looked over and appear to be good. 2 upper spark plugs had soot on them meaning the engine was running to rich - lower 2 plugs had tar like goop. Took appart carbs and cleaned them - but it didnt help.

had the same problem when I changed my engine. turned out to be wires broken for the distributer. the distributor cover is on the lower front on the left of the engine, with wires coming out of it. check that, also make sure the bike is in time and dist. magnets are good

I think what you are looking at is the crankcase vent line.....the blowby gases from the engine flow into the airbox to be burnt with the incoming air.
Have a close look at the oil level in the crankcase....Yamaha usually has an oil window ....down low on the side of the crankcase....with the bike warmed up and shut down a few minutes on the centerstand...the oil level should be about half way in the glass.....overfilling the crankcase will cause the oil carryover situation you describe.

Hi and welcome to the site,

Initially, by "won\'t kick over", do you mean the starter will not turn? If yes, check the starter relay. To locate the starter relay, follow the cable from the battery's + terminal.

If on the other hand, the starter will spin but engine will not catch, then check for presence of spark on the plugs.

Good luck and thank you for asking.

I think it is marked on the engine casing right where you pour the oil in. I believe on that bike it is 3 quarts with oil and filter change

have a look in the headlight as all the wiring is usually at the back there , you could have a loose connection .
Just unscrew the headlight and have a look through all the wires and make sure all connections are ok .

most likely yes, there was little change in the parts in these 1980's bikes. of course no engine parts will cross over