Just bought a 1980 xj650. Need help. Loads of issues.

So I bought an xj650 maxim. Ran great for two days. Now it seems to be running cold on one side of engine (exaust wise) and very rich running conditions.( I determined by state of plugs). What should I do? Cannot seem to find parts for this bike. Something also to note this is my first motorcycle so I do not know alot of what to do.

 

You can find just about everything you need at XJ BIKES4 EVER.COM
If you are not good with nuts and bolts ? like getting your hands dirty, have a lot of spare time it may be less aggravating and financially cheaper to buy a new retro bike

 

It runs (somewhat) so you know you have some air, fuel and spark. Electrics are working for you (Right?) so another plus. I’d confirm all cylinders are firing and check/clean your carbs and jets for fuel supply. If you can turn a wrench and read a manual, you’ll be okay for the most part. Tons of help on here, just search for topics or post your issues. As long as you're willing to listen, there’s folks on here happy to help.
Good luck!

 

Have you looked inside the gas tank with a light? If she ran good for a few days and then started to give you issues, I am guessing carbs got junk in them. If there is no inline fuel filter in the fuel lines and with the age of these bikes, I would guess some junk got in the carbs. I could be wrong.

 

Ok so electrics are good. Carb is well....very clean as this morning I cleaned it. It runs a little better. However half the engine no matter how warm I get it , the exaust is still cold. I'm not afraid to get dirty turn a wrench or anything like that. However after carbs electrics and fuel tank checks I'm drawing a blank on what else it could be. Perhaps valves? Or timing?

 

Trade the spark plugs between a warm and cold cylinder to see if the issue follows or stays?

 

Upon inspection after cleaning and putting carburetors back I found an air leak issue. Theres a nipple for sync. That was loose when I removed it the idle picked up and engine ran fine until the throttle was revved and then it back fired. Any ideas of what could be going on?

 

Good trouble shooting keep it up. Have you checked to make sure all the plugs are firing? Pull all the plugs put them back into their boots and crank the engine. See if you have spark on all 4. If you don't have spark, you will need to remove or clean some of the spark plug wire. Unscrew the boots from the wires and check the ends of the wires. If you see green nasty wire in the end, that will need to be taken care of.

 

Where are you from

 

Carb? Carbs surely? There is something called church of clean on here - it refers to cleaning the carbs, spotlessly, including the passagways from jets to the idle mixture screws and progression holes, the starting enrichment metering, and replacing the butterfly seals. Personally, I'm not a fan of newbys completely breaking these down, there are a number of pitfalls for the person maybe lacking in attention to detail - checking the passagways with squirting carb cleaner and compresed air should suffice, sure bad throttle seals will give you idle issues, but more inconsistency than anything else.
Edit to add, the outer two, and inner two cylinders share their coils, so if one outer is running, the other outer will be getting spark, same with the inners. So it's unlikely to be a spark issue you have. It could be a plug problem though..

 

Those nipples need to be on, not off.

 

are you a Necromancer? This thread is from 2020.