Xj550 Starting problems.

This bike has had a host of problems, im slowly getting them all worked out.
81 xj550 mikuni carbs

Here's what i've done:

Surgically cleaned the carbs.
Cleaned the enrichment circut very well
Adjusted the float level to the correct level
Adjusted the valve clearence
New Needle valves.
Made sure the petcock is working properly and is flowing to the carbs.
The bike has a very good fuel filter that is clear and not plugged.
No vacuum leaks.

Here's the problem:

I put the carbs on yesterday after taking them off to repair a sticky float. Made sure everything was clean again since i had them off. Checked the float level again. Bench Synced the carbs, opened the idle screw just a little bit. I put the carbs on the bike, and was having a little hard starting, figured it was just since the carbs were dry. I put a small spritz of ether and it fired right up.

With the choke the whole way actuated, the engine races up to 5 grand... so that means the choke is working, right? Took it for a ride, ran great, shut it off came back a few hours later and started it up a couple times and it started right up.

Onto today. Went out, put the choke on and tried to start it. It just cranked and cranked like it was out of fuel. I made sure I had fuel and it was getting to the carbs. Yep. Kept cranking it. Not even a burp. I put a large amount of ether into the carbs, still no start.
I figure I had it flooded and the cylinders washed down. I pulled the plugs, and the cylinders were dry as a bone, no fuel what so ever. I have spark too. I took alot of time to clean the enrichment circut with a small wire gauge drillbit and compressed air to make sure it sprayed a very nice stream on all 4 carbs. Why is it that it's not pulling any fuel into the engine unless the bike is running?

Thanks

 

How many turns from soft bottom are the mixture screws set at? 2.5 - 2.75 is a good starting point for doing the running synch.
Why is it that it's not pulling any fuel into the engine unless the bike is running? Open the gas cap and see if the big rubber washer is still intact.

Gary H.

 

DId you try starting with the petcock on PRIME ? It looks like a fuel delivery problem.

 

did you use see through fuel line?? you have to keep the line below the petcock or you can get an air bubble in the fuel line. @quebecois59 suggests set to prime,
I have had to do this a few times.
and by opened the idle screw just a little bit you mean the knob in the rear of carbs
yes your enrichment circuit is working if it goes to 5k rpm.

mixture screw will end up at a 2-3/4 to 2 7/8 turns up from soft seat 2 1/2 is a good place to start as suggested

check your battery voltage when cranking bike if it drops below 10 volts the bike will not start but will turn over at a good clip. did not fire on starting fluid i would suspect voltage
also check out your charging voltage once you get the bike running it should climb to 14.4 volts at 2k rpm

after bike is warmed up well it should be set to 1200 rpm that is what it says in my side cover which is different than the fsm which says 1050 rpm.
look on the side cover for data

there is a vent in the fuel cap but I do not think this is your problem

 

The mixture screws are ballpark as described. Yes it is the idle screw between 2+3 bowls. Yes it was on prime, filter in the tank is clear, and I can see the fuel filling up the in line filter The whole way.

. I'm thinking it may be electrical also, but it has a brand new battery that I just charged over Christmas and put on last weekend. It seemed to start easier with a battery charger. Charges corrctly 14.5v, and the cranking voltage is 12v Is there anything between the battery and the ignition system that would cause a high resistance symptom or something?

 

If the engine has cranked for seconds and your plugs are bone dry, I doubt it is an electrical problem.

 

clean the connections also the ground conections at motor and frame .
do you have the glass fuses?
get one of these to jump across the clips to test the clip


tci pluged in tight and clean.
I would check the coils ohms the plug cap ohms and the pick up coils ohms to rule them out.
when you test the cap ohms trim back the plug wires 3/8 of an inch a little dielectric grease or silicon on the plug wires will help put them back into the caps they unscrew

specs in this link
The Ultimate Relay, Switch, Sensor, and Diodes Guide

when you cleaned the carbs could you spray cleaner into main air jet and have it come out
the holes where the emulstion tube is under the main jet?
into the air jet and come out the holes in carb throat and pilot jet?

could be your needle valves got pluged from the first fuel fill up. or screens on the valve body

also open up the bowl drain screws to confirm fuel in the bowls

 

also check for 12 volts at the right side connector at tci box red white wire (may be red) .
pick up coils are to be ohmed out on left connector black wire is common
read gray to black and orange to black

on right connector you can read primary of coils
unplug connector read orange to red white and gray to red white
if primary is out of spec read at coils you will have to remove gas tank

have you seen this diagram
http://www.frankjohansson.com/stuff/xj550/XJ550ElectricalDiagram.html

 

If you spray ether and get nothing ,no back fire,then you have no spark,still could have fuel issue.but I would look at the tci....because they ARE
the devils work.

 

is your avatar a painted helmet?

when my caps failed and 1 pickup coil it was intermitant until full failure.
bike would run then fail then run after sitting

 

Yes it is she did this one too

 

+1 on no spark
-1 on heading straight to the TCI and their being the devil's work.

 

OK the devils work might have been a stretch.... what I meant was check the connection since it seems to be an intermittent problem.

 

Besides everyone knows TCI"s are the work of wicked witch's

 

They are the (somewhat distant) spawn of Bell Labs

 

the neg 1 is going to the tci before testing all other components

 

Being serious for a Minute,after reading the whole thread it looked like most everything else had been checked and tested.at any rate. I here by sincerely apologize to any devils,wicked witches,and TCI"s that I may have offended.with my thoughtless comment.

 

SHHHH if the tci hear you the will decend on you inflicting all kinds of pain and misery

 

that's why I edited it and said sincere.you can't be too careful