82 XJ550R starting and running issue

Here's the whole story.
So I have possession of my father's 1982 xj550 Seca. Prior to this, it sat in a shed with gas in it for 10+ years.
Removed the tank, drained the gas, removed the carbs, replaced the battery, and spark plugs(no resister), changed oil and filter.
My friend cleaned the carburetors and we replaced the needles and emulsion tubes. When we started the bike to do the dynamic sync(with yics tool installed), one of the spark plug caps was arcing. So I replaced them with new resister caps. We kept running into an issue with carb 2, so I took it to a local repair shop and had them go through the carbs. It had a bent float pin and the brass bushing came out in pieces.
Everything got put back together and i took the bike home. When i went to start the bike, it would crank and crank but not start. Called the shop and they said to hit it with some ether. Started but the revs were hanging. Also when in gear with the clutch in, it was hanging at about 4k rpms. when i let the clutch out a bit, it dropped back down to 1.2k. Took it back and they went through the carbs 2 more times in case of a reclog. They pulled the YICS tool and a couple orings were gone so they replaced them with my extras and reinstalled. When starting they noticed the spark was weak, but when they let go of the starter button, there would be one strong spark. They tested the coils and the coils tested bad so I ordered new ones. While they had it, they started it like 10 times and had no issues. Then the last time they tried, it wouldn't start.
At this point we thought it was the ignition control box. I had a spare from a donor bike, popped it in and it fired right up. Rode it around, revs didn't hang, throttle response was good. Later on I took it on the highway, got it up to 80mph. When getting off the highway and coming to a stop, it stalled. Started it back up, next stop it stalled again. Giving it a little throttle kept it from stalling after that.
About 8 hours later, I went to ride home and it wouldn't start. Hit it with ether and it fired up but the idle was sitting around 1k and stalled. I adjusted the idle so i could at least make it home, and it started doing the clutch 4k rpm and hanging revs. Tried starting it today and it belched once and that was it. it just cranks away.

Any ideas?

 

Vacuum leak at manifolds is a possible cause

 

did you remove and clean the enrichment plungers and the tube in the carb bowl and the well in the carb bowl?
carb to manifold boots may be leaking (vac) you can clean them with carb cleaner and coat with black rtv to seal them up could also be the gasket on them.
when i removed the carb to manifold boots the secrws were so loose that the weight of the socket wrench was all that was needed to get the screws moving , not torqued properly 3 bikes all the same.

did you replace throttle shaft seals?
have you checked the valve clearances? it is where you should start we have a link for that too.

do you have a factory service manual? How about a carb rebuild book? start a conversation with me if you want a copy of each NC .

a few links for you the naked one is carbs cut up by circuits.
THE SECRET LIFE OF CARBURETORS

Something New, Something Naked

IN THE CHURCH OF CLEAN

 

did you clean the tank? you may want to install a fuel filter


here are some links for you that will help you understand and fix your bike your self
some reading for you

The Information Overload Hour

The Ultimate Relay, Switch, Sensor, and Diodes Guide

IN THE CHURCH OF CLEAN

THE SECRET LIFE OF CARBURETORS

Something New, Something Naked

TALKIN' TECH: Various thoughts on various issues

AIRHEAD VALVE ADJUSTMENT with Pics

AIRHEAD VALVE ADJUSTMENT Part 2: The Tool vs. ZipTie -w/pics

Choosing Oil for a Wet Clutch Motorcycle


SAFETY ALERT Drum rear brake bike owners please take a look


our forum supporting vendor plenty of parts and advice Chacal

XJ4Ever - Supporting Vendor

his web site
www.xj4ever.com

 

was 80 as fast as you went or the bike would go? it should have a lot more top end than that.
did you lube the chain ? id it as standard chain or o ring or x ring chain.
if it is a standard chain take it off and soak it in oil overnight then hang it for a few hours to let excess oil drain off.

o or x ring chain may not have a master link riveted on you can use spray lube for them.

 

Forgot to mention the bike only has just over 4k original miles.

• Carb boots are new.
• Tank was sent out and derusted/coated. In line filter was installed.
• The valves have not been adjusted.
• No idea what wasn't actually cleaned in the carb bodies. My friend had them broken down completely to my knowledge and the shop went through them again a couple times.
• I only rode it up to 80mph, it definitely would've gone faster.
• No master link, oiled with spray chain oil.

I just find it weird that it ran perfect for a couple hours and then back to square 1.

 

HAve you checked to be sure that the throttle cable isn't binding?

Unhook it from the carbs. What's the idle like with it disconnected?
How is the throttle response when you move the carb linkage manually?

Keep the YICS tool out. YICS is a good thing, really.

 

4 k miles it is time to check your valve clearances.


may be the vent in the gas cap is clogged
Your Gas Cap and You
open cap next time it stalls
idle should be 1200 by spec but 1500 is better

 

I took the yics tool out and no go. Started it with ether and checked around the carb boots with propane and there was no change in idle. I increased the idle to 1500, didn't make a difference in throttle response.

 

I also find it weird that after going through all that, it was running fine with the donor ignition module but after a highway ride decides to go back acting exactly like it used to; i.e. before you swapped to the spare module - running but not properly and hard to start. I wonder if it is not fuel related but an electrical issue. I'd check each spark plug wire carefully, remove the plug caps and check for green corrosion on the wires. Cut each wire about 1/4" shorter, check each spark plug boot for proper resistance (5 K Ohm if I recall), remove each spark plug and clean them good. Now reassemble the boot onto the new shorter wires with a little dielectric grease, ground each spark plug and crank with a known good, fully charged battery. You need to see a nice, clear blue spark on each plug. Check the power to the coils and the connections to that ignition box. Make sure all are good and corrosion free.

Next, put all plugs in and try to start it again, noting how the bike reacts (does it misfire? does it catch on only one or two cylinders? do you smell unburnt gas at the tailpipe?)