650 Maxim startup / running problems.

I have an '82 XJ605J that I am trying to get running. It has just under 9K miles and appears to be in fine shape with one exception: previous owner says that #4 carb needle was cross-threaded and the carb is screwed up.

I bought a set of carbs off of eBay and they appear to be in decent shape. the bowls all had some white patchy discolorations and the floats have what I assume to be varnish on them, but it appears the fuel was properly drained out when they were last used. some moisture got in at some point and there is a small amount of surface rust in the bottom of the bowls at the drain plug. The floats all stuck at first, but I loosened them, cleaned them off with some brake cleaner, and reassembled the carbs and put them on the bike.

When I set the tank to prime, I walked away for a minute and actually had fuel leak out. This suggests to me that one or more of the floats stuck? Or am I in error and all is well?

When trying to start the bike, it tries to turn over but doesn't catch. I got a couple of good backfires and at one point it started and ran for about 5 seconds, but then died out.

I checked the two spark plugs on the left side and both were black, so I will be replacing the carbs.

Does anyone have any suggestions on how best for me to proceed? While I have some mechanical aptitude, I have *never* worked on a motorcycle before and only a small bit on cars. The shops around here aren't willing to work on something this old.

Thanks for your help and advice,
Mike

 

make sure you clean the enrichment circuits. are the fuel mixture screws uncovered? if so i would buy some vacuum gauges and a colortune and go to town.

Enrichment circuit

Spending a few hours at MiCarls shop over the weekend really proves to me that as long as you have the right tools and a good understanding anyone can clean and tune their carbs perfectly.

 

I did check them when I tried to clean the carbs, thought they were clear. I am going to do more of a soak this time - just didn't have anything big enough to soak them in without breaking them apart - which I really don't want to do ...

 

Q-

You definetley have a float sticking or mis-adjusted. Before you take the carbs off for cleaning again, I would do a float level check if you can get the drain screws out. Mark the levels on the side of the carb with a pencil and when you find one that is correct note it. When you get the carbs off compare float level heights with a known good one and see how much you need to adjust it. Also, polishing up those old float valves with a Q-tip helps to eliminate the sticking problem.

You dont want to soak the entire rack of Carbs in cleaner as it will eat the shaft seals up and any thing else that is rubber. Soak the bowls & floats. Clean everything else minus the rubber with a spray carb cleaner.

 

ur float valves could be leaking. With the floats make sure that the pin that holds the floats in place is spotless. make sure that you really clean the carbs good.

 

I will do. I didn't realize how to get the floats off when I was looking at them before - hadn't done enough reading yet. I will be taking the floats off, examining the float needles cleaning the floats of all varnish, making sure they float, etc.

Thanks for all the assistance folks.

Michael