took the carbs to church and now I cant get the bike to start

Hello, I have an xj 550 maxim 82', did a carb rebuild, bench sync, measured and fixed valve clearances, even fixed the gas tank which was rusted and leaking. I turned the mixture screws 2 3/4 turns out. it turns over when I press the starter but it doesn't start up even with starter fluid. choke was pulled out as well. there was gas in each bowl as well although I have not done a fuel level check on it. It was running at one point and then I found it had a vacuum leak so I think the fuel levels are fine. I will check that at some point but I want to at least get the bike running to some degree and tune it. I am at a frustrated loss. any advice is welcomed

 

start by ohming out the ignition system
are your plugs fouled that will happen with starter fluid.
measure battery voltage before starting and during starting if voltage goes below 10 volts your when cranking bike will not start.
looking for 12.8 volts before turning on bike.

keep battery fully charged.
hit thee prime selection with petcock to make sure bowls are full 5 seconds will do it.


specs for ignition system and charging system will be found here
The Ultimate Relay, Switch, Sensor, and Diodes Guide

remove headlight fuse to keep headlight from coming on.

clean tci connectors and ignition coil connections use electronic contact cleaner spray and dielectric grease. battery connections dirty connections cause voltage drop.

check voltage at battery. then fuse in and out then at tci for the ignition system. you are looking for voltage drop as you go deeper into wiring.

clean ignition switch contacts. voltage flows from battery to main fuse to ignition switch then back to your other 3 fuses

Clean and lube the ignition switch

you will need to check wet fuel levels
Setting the fuel levels

 

Yep been there done that. Pull the plugs, are the wet? Place the plugs in the boots and check for spark on each of them. If the plugs were wet, shine the light down the plug hole and see what you have going on in there, wet, full of carbon? If you have compressed air blow out each cylinder as well to dry it out well. If it was not wet and you have everything hooked up, gas carbs ect, they should be wet of have gas in the cylinder.

Just tapping on the side of the carbs might free up a stuck float bowl as well. Be ready to turn off the gas if you didn't do a fuel level test outside the bike.

Let us know what you are doing to fix the issue and good luck.

 

Hey guys, Quick update. I replaced the fuse box and am quite pleased with the craftsmanship! and it freaking works. I am having an issue with the left turn signal not blinking or blinking once or twice. any thoughts? then the real head scratcher. I'm trying to set the float heights and they were all in spec. when I am measuring the fuel level though they are 10mm from where it is supposed to be which is the section where the bowel and carb body meet. I am fiddling with the tang to increase the fuel level but wont that take it out of spec for the float height?

 

Fuel level in-situ over-rules float height with carbs upside down off the bike.

 

thanks man, I am hoping that is the case. its just weird that at one point the bike was running, granted with some issues (vacuum leak in the carbs, shim clearances, etc.) and now the fuel height is low and probably the reason why the bike wont start and the sparks were dry. I feel like I am playing whack-a-mole with these problems

 

If you put a new float needles they are a different length than the originals which is why the float Spec is not as accurate as the wet set

 

Yes the carbs take some time but it is well worth it. If you don't take the time then you will be taking them back off anyway, so get it done right the first time. As for the turn signal issue how is that battery of yours? New or newer and fully charged? You didn't put any LED's in anyplace? You have changed out the old fuse box but have you cleaned up all the contacts for the rest of the connectors? Weak battery and possibly a bad turn signal relay.

 

new and has been on a trickle charge. no LEDs. Probably the connectors or relay switch since I haven't checked them. The fuel Levels were crazy low and I bent the tangs and got them to a more appropriate level but my two outside bowls are nearly in range and my two middle bowls are absurdly low!! any idea what can be causing that? I will be taking pics this weekend of what I am talking about. just very frustrated, I feel like my floats are nearly as high as they can go to let in max amount of fuel. I am about to just take them out to see if the bowls will overflow. I did put in new needles but thought they were the same height as the old ones but will double check.

 

What height did you set the floats at?

 

15cm

 

Whoops I mean mm

 

I believe for the xj550, you should make your initial setting at 21.5 mm. The 550 rack is really finicky, so you’ll surely need to do a wet setting.

the 550 came with a heat shield underneath..... but most times we will not re-install them because in order to adjust float levels, it has to be removed. In order to remove it, the rail screws must come off. When those are removed, the rack becomes a bit “loose”. This will mess up your sync! So just leave it off.

that said, the mixture screws for the 550 could easily end up even around 5 turn out.....

As I said before, the 550’s are quite temperamental, and often take more time to dial in.

dfox

 

Thanks for that! I did put the heat shield back on but will leave it off going forward. They were initially at 21.5 mm but the wet levels were very low

 

Should I be checking the fuel levels while the bike is on the center stand or should they be off the bike and perfectly balanced?

 

Many people check levels with the bike on the center stand, others build a PVC rack to hold the carbs on the bench.

there are numerous pics of carb stands through the forums.

 

Alright, Latest update: I have the carb wet levels finished or at least as close as I could get them! the bike did start!!! but only with the choke on and it went up to 6k and definitely smelt some burning plastic. I cant get it to run without the choke on or to get down to its ideal idle. any thoughts on what I can do next? i assume I have to do something with the Idle screw?

 

Keep it running, and play with the idle screw til you can hold an idle that’s not too fast—then try to SLOWLY turn off the enricher. You may have to play with the idle screw , you may have to play with the throttle. Somewhere around 1100-1150. You need to get it to idle on its own, so you can get ready to do a running sync. The running sync, and the color tuning will dial it in a lot more. The bench sync is just to put the rack in a state where the bike can start up and run to warm up so you can prepare for your running sync.

 

any advice on a good way to turn the idle screw? my hand wont fit

 

never mind I tried it from the other side and I could reach it. My other thought is once I get it to an ideal idle, I shouldn't have any trouble getting it to start when I push the ignition. For humors sake though, if it is still having difficulty firing or takes a while to start what would you suggest I look into as far as possible culprits?

 

Have you done running sync? If not it should start right back up while it’s still warm. You want to hook up pretty quick. If it gets cold again, you’ll have to pretty much start all over again

 

Not yet, I have a homemade manometer and tried to make my own yics tool but it doesn't fit lol.

 

Forget about the YICS tool. You don’t need it.

 

Why is there so much about doing it vs not doing it?

 

They want to sell the tool. Many of us did like you are doing and trying it right by the book. Other on here will also say you don't need to use it. Just to the best you can without the tool and it will be close enough. Going through the effort to make or buy the tool and then use it, will not bring you measured benefits. Try it without the tool, do a good job and you will be supper happy with the results.

 

So update, got the levels set off of the bike and put the carbs back on. the bike started back up instantly! It then revd up to 3k and as I let up on the enricher I could get it to drop down to 1500, but when I take off the enricher it just dies on me. I have decided that I will give the carbs another thorough cleaning and check all the passages but any other ideas as to what could be causing that? I took those carbs to church last summer and replaced everything that is recommended.

My other issue is that I would hear a click from the solenoid half the time I tried to start the bike. going to rebuild the starting motor and clean the connections/relays.

any thoughts on the first problem would be greatly appreciated!!

 

It is still cool outside. Did you let the engine warm up enough to run without the enrichment being used? Sounds like not.

 

when it starts with the choke, it running on the choke. when you shut the choke off it runs on the idle screw, maybe all you need to do is turn the idle up.
it's going to be ruff and want to stall and race until you get a running sync started. the trick is to get it running bad so you can get a tune started

 

Try shorting (blade of an INSULATED screwdriver) across the two solenoid terminals............if the starter motor turns the engine over just fine, then the starter motor is okay, and the solenoid may be toast. OR.......it could be the START pushbutton on the control switch; pushing this button completes the ground circuit for the solenoid, and with no or poor ground your solenoid can spazz out as-if it were toast.


YICS:

https://www.xjbikes.com/forums/threads/yikes-all-about-the-yics-system.14757


To review:

According to Yamaha, the function of YICS is to promote more complete combustion at low to mid-range rpm by swirling the mixture around the combustion chamber. They never made any direct power claims -- the system was promoted as increasing mileage up to 10 percent and promoting lower emissions through a cleaner burning charge. The increase in mileage was not through leaning out the mixture -- the increase in mileage and reduction in emissions was because less throttle was required to maintain cruising speed. They could use the same cam timing, jetting, etc. (for performance) and still meet EPA regulations. Yamaha stated that the greatest effect was while cruising at 50 to 60 mph.

The swirling accomplishes two tasks: first, it assists mechanically in atomization of the fuel and second it speeds and distributes the flame front (and therefore combustion pressure wave) more evenly throughout the cylinder. The later "Genesis" (water-cooled "X" engines) design accomplished this even more effectively through the 5-valve design, which accomplishes the same task through a wider rpm range.


To blank or not to blank (during engine synch), that is the question. Ok, what is the function of synchronizing? Manufacturing tolerances and wear. Multiple carbs offer the advantage of increased power and performance over the single carb configuration for reasons beyond the scope of this discussion. But at a cost.....

As each carb is dealing with a fraction of the total air and fuel flow requirement, each carb must meter things in fractions of the total. That makes for some very tiny tolerances. In effect, we have 4 separate engines -- if one is fighting the others, then we are wasting power and fuel and are worse off than we would be with a single-carb setup! So it is crucial that each one be perfectly adjusted and that all 4 then be synchronized to work in perfect harmony.

So, how can we reliably adjust an individual carb based on the results of the adjustments, if it's companions are contributing to the results? Now, to be fair-----if the bike has been reasonably well maintained and the cylinders are all fairly close to begin with, you can usually get away without blanking the YICS passage and still achieve a reasonable state of tune (synch) At the opposite end of the maintenance spectrum, the YICS passages are often already plugged up with many years worth of accumulated grunge and grime, so the bike is effectively being tuned with the YICS system disabled and the presence of the tool is irrelevant. But we have seen some examples of carbs where one cylinder was effectively relying on its neighbors to supply most of the mixture through the YICS system, and this most certainly affects performance, especially the top end.


A Dirty Dirty YICS; take a look for yourself:



So, our recommendation: for an engine with approximately equal compression across the cylinders and valve clearances in spec, make sure the YICS passages are clean and use the blanking tool to tune the carbs.



The most important point to remember:

The pronunciation of "YICS" is "yiks", not "yikes!", no matter what anyone else tells you!

 

it was a warmer day, at least 70 and the bike was running for a few minutes I am going to try it again once I fix the electrical issue and make sure the carb passages are clean...again...

 

(This was a reply to the question about what might cause starting problems after getting an ideal warm idle) Enrichment channels plugged. Mixture screws set too rich or too lean. Other mods (pods, exhaust, K&N air filter) without corresponding changes to pilot jet sizes. Valves out of spec. Float height.

 

valves were changed to be in spec, float height at ~2mm, I do have a K&N air filter that I put in a few years ago, the bike was able to run with that change. mixture screws set at 2.5 turns out. if the enrichment channels were plugged wouldn't the choke not work?

 

does the air filter type warrant a different pilot jet size?!

 

Depends on how plugged. So, originally when you installed the K&N filter you didn't have a cold starting problem, but now you do? Those enrichment circuit galleries are pretty small - easy to clog, hard to clean.

 

The air filter was one of the first things I replaced years ago, I eventually took the bike to a mechanic who kinda fixed some of the problems, but he didn’t change the shaft seals so I had a vacuum leak. I took them apart and really cleaned them but perhaps they have had funk or something since I have been running fuel through them

 

Checked the starter motor and it works fine which means that it is in the wiring, right?

 

Hey guys, found this notch, is this going to be a problem?

 

At my wits end, just took the carbs off and checked all the jets for clogs and they are all good, checked the other tiny wholes in the carb bowls and sent a wire down the shafts. Starter and solenoid both tested and worked and sprayed contact spray on all of the connections.
Is this tube supposed to be plugged when I’m starting it? I felt like it should be since it isn’t hooked to the gas tank. I’m messing around with the idle but the bike is either all or nothing! Any ideas?!

 

Today I plan on trying again to get the idle with the enricher off, I am going to try and turning out the air mixture screws a quarter turn to see how that effects it. I also am going to remember to use a fan this time, the engine started spitting out some oil. good learning moment!

 

Have you not listened? Vacuum leaks? And you think as if it's OK to leave the vacuum pipe open while trying to run the engine? Some thought on your part might not go amis here.... come back with your thoughts on this?
And you haven't turned out the "air mixture screws" out at all yet? They aren't air mixture screws, they are mixture screws, start introducing "air" into it and you could confuse them with air screws, which do the same things, and don't exist on this engine, but in the opposite way - d'you see where this could lead?
So put the mixture screws 3 turns out, start the bike, reduce the enrichment - you might not even need it to start. Once running without enrichment you can do a running sync. If the engine doesn't run without enrichment screw them mixture screws all back out some more until it does.
Magic doesn't happen, it's all logical, but you have to understand the process.

 

The vacuum leak was happening when I had the fuel tank hooked up and wasn't using an auxiliary tank so when I finally switched over I had neglected that part until yesterday.

I double checked for vacuum leaks with the vacuum pipe closed and it did not take off when I sprayed starter fluid around the carbs so there is that positive note.

I sincerely thank you for the bluntness of your messages. The mixture screws are set at two and a half rotations out while I have been working on it this go around. Also earlier in the thread I saw where it can sometimes be 5 full rotations for the idle screw to be turned out on these carbs. It has been difficult to measure since I have to use a screw driver to adjust it but once work is done I am going to give it another go.

 

Here you go then, screwdrivers have been used since mixture screws were invented. This is how you do it.
Mark your screwdriver, if it doesn't have a makers mark on it. Place it in the slot, somewhere you can see this marking. Turn it out, counting revolutions - in this instance, to make this easy, go for 3 turns. Anything in between you just guesstimate.
Apologies for being blunt, but two pages in and your still asking silly questions instead of riding - people will lose interest, and you'll get no help.
Krack on, and come back to tell us it's running and you've done a running sync, and it idles smooth as anything.

 

Taking apart the spark plugs and look what I found! 1 is the closest and 4 the furthest away. I can smell gas in the first two but not the second two. Taking the carbs off and doing a thorough recleaning of the fuel passages

 

Ran a compression test with the carbs off and the bike wasn’t at operating temps.
4 is 175
3 is 165
2 is 170
1 is 170
Manual says it is supposed to be 130-160 psi, I feel like the good news is that I don’t have to replace any rings or bores. Could my valve clearance be an issue? I put those into spec last summer but will be doing a quadruple check when I take the top off to fix a small leak in the gasket.

mom another positive note @XJ550H helped me solve the case of the mystery wire which turned out to be the low oil switch. The wire diagram has that marked as if it is supposed to be a black wire with red stripe, not a white one.

going to check the coils next, I have spark with all four plugs but it doesn’t hurt to be thorough

EDIT: I got 2.7 ohms for both coils but got diddly squat for both of them on the second test between the coil and caps. How am I getting a spark If I’m not getting a reading? Watched a YouTube video on top of reading the manual on how to test it

 

plug wires are 21K ohms with caps on turn the dial on the meter to higher setting

 

Still no reading

 

remove the caps the cap unscrews from wire cap could be bad or end of plug wire may be corroded trim wire back about 1/4 inch.
wires should read 11k with each cap at 5k ohms.

if they are oem caps youu will see a slot in the spark plug side snug it up there is a resistoe in there thats replacable.

 

thanks, I actually tried this after your earlier post. The wires still had no reading and I am sure that the caps on the Xj550 are 10k ohms, my readings were 8,8,10, and nothing on my 3rd cap so I guess I need to replace both coils and one of my caps, I will probably just replace all of them, but you say there is a little slot that I can just replace instead of all the caps? hmmm I will look into trimming the wire back and see if that does anything.

 

Replacement NGK caps are a few bucks a piece. I hadn't heard of being able to just replace the resistors. That's cool... but how much would an OE resistor run, if it's even available?