Some trouble getting her going...Help!

First post, thought this forum would be the place to go for some advice on getting the maxim going strong.

Here is where I am:
I bought the bike (82 xj550) for 250$ with a clean title. When I picked it up It ran, but pretty rough. I looked in the tank and it was rusted to hell so I got all the rust out and coated with por15. I also took apart the petcock and tried to clean it out with some carb cleaner (I think this might be the problem.) New Plugs, air filter and battery and it cranks real strong but wouldn't turn over. I sprayed a little starter fluid in there and it turned right over and ran at 3/4 choke 2-3 minutes before cutting out. I tried to start it again. No luck. Again I sprayed the intake with some starter fluid and it ran for 5 seconds then cut out on me. It only starts with starting fluid and only goes for about 5 seconds.

I think it is the petcock for a couple reasons:
When it ran for 2-3 minutes I think it was from the gas that had been left in the bowls of the carbs. After that I'm not convinced it was getting any gas. I think the short spurts of it running were from the starting fluid.

I know I have compression and spark. Any help would be greatly appreciated.
Thank you, Rob

 

You should have a PRI (Prime) setting on that petcock. That bypasses the vacuum-actuated valve. Does it run on prime?

You can double-check by disconnecting the fuel line, letting it run into a bottle, and switching to prime. Fuel should flow freely into the bottle.

 

On prime it starts and runs for no more than 30 seconds with no throttle response.

 

Update: The bike starts when it wants to, it will only idle above 3000. I just took it around the block but it had barely any throttle response(Could this be because of poor clutch cable adjustment?). Then it shut off on me. wouldn't start back up.

It seems to start better after it rests for a while.
Thanks. Rob

 

Your carbs are probably filthy inside. Look for plugged jets. Gummed up float needles. The inside should look good enough to eat off of and I encourage that. LOL. You should have a manual if you don't have one already.
Use the search to find all the carb cleaning tips and techniques. GET TO KNOW YOUR CARBS INTIMATELY!!!!! Take them apart and post pictures as you go.

More will chime in with their 2 cents.

Pull the back wheel and make sure the rear pad is not trying to delaminate.



We love pics!

 

Make sure you get the needle valve seat out and check the beanie screens....Like Bill said they have to be clean enough to eat off. Take the advise and clean them thoroughly the FIRST TIME. Search for carb cleaning the whole 9 yards and follow it exactly. You'll be glad you did.

 

Yep its time to "get to know your carbs". Take them out and rebuild them. Lots of good information on this site on how to do it.

 

Appreciate it guys, guess I'll be getting dirty this weekend.

 

Best advice i can give you is, upon taking apart the carb take visual memory of everything thing, go to Lowes or welding shop and get a welding torch tip cleaner it will have many different gauges of steel wires, this is great for cleaning debris from the center of the jets and removing any gum/varnish you may have.. make sure to keep at least 4 cans of carb cleaner with you.. pb blaster is gonna be you friend if you find things become frozen or stuck.. DONT RUSH! the slower and methodical you are the better the results. there is a saying that goes, if you couldn't find the time to do it right the first time, how you gonna find the time to it over again. i wish you the luck and once you know your carbs the easier it is. one of biggest things people forget to do is clean the power valves, like stated before there is a ample amount of resources at your disposal.. i recommend rick massey's.. happy carb cleaning and remember in the end you treat her or him right and it will treat you right.

 

I can support everything you posted exept this. The steel "wires" will ruin the jets if they are incorrectly used. The brass jets are soft by comparison and will be deformed by the reaming action of the tip cleaners (which are files incidently). Jets are best cleaned using either nylon or brass bristle/brushes. I use a baking soda blaster myself, cheap and easy to use (also non destructive). Just don't breat the dust.
Otherwise, take your time and remember, some folks here had to clean their carbs two, three and even four times before they got things where they needed to be.
Good luck!

 

Robert's advice is spot-on. Never use any instrument "harder" then the material the part is made of. Nylon brush bristles are great.

Anyway, the 550 has Mikuni carbs. Have a look: http://xjbikes.com/Forums/viewtopic/t=31061.html

Be sure to set your float levels using fuel and the "clear tube method." The Mikunis are quite sensitive to improper float levels.

You'll also need to check your valve clearances and adjust if necessary before trying to get the carbs sync'ed. http://xjbikes.com/Forums/viewtopic/t=14827.html

CHECK THE REAR BRAKES FOR DELAMINATION BEFORE ANY RIDING. They need to be visually inspected; you cannot go by "feel" or if they seem to work fine. No joke here: http://xjbikes.com/Forums/viewtopic/t=15874.html

Also, once it IS running, and you're sure it's gonna stop, be sure to keep a close eye on the chain. If the chain is rusted internally (quite common if the bike sat under poor conditions) it will quickly fail. Be sure to replace the chain and both sprockets as a set.

 

Will I need to replace the float bowl gaskets?
Thanks, Rob

 

Only if they are torn, overly hard or just plain mashed into poor shape. I reuse my gaskets without issue regularly.