Yet another tuning issue

you can use a strand of wire from a 16 ga stranded wire to clean out the holes
the shim in the slide needle is just a thicker washer or a washer that is shaved

 

Use the wire to clean out which holes??

 

2.9 could be just the quality of your meter compare the reading with your friends bike if you can. have you looked at the pickups? i just replaced mine one failed. the ones I took out looked like they were bent probaly hit with wrench when po did a shim change.
do you have access to a timing light? timing is not adjustable but you should check it to make sure it is in the window.

 

in the side of the emulsion tubes I really think this is where some of your problems lie.

 

do your slides pass the clunk test? there is a video on it in the church of clean or info overload .

 

Ok. I will check on his next chance I get. Again I got 2.9 ohms for primaries and 21 ohms for secondaries (with caps on). This should be all good right. When I look at the coils anything specific I should look for. I don't have access to a timing light. I will look into that.

Thanks for all your help. What else you got?

 

When I had the emulsion tubes out they were soaked in cleaner. I can't imagine there is anything left to clog them up. They were sparkling.

Yes. All 4 slides drop nicely.

 

could you see through the holes in the sides of the tubes there are sets on four sides of the tubes.

 

I don't remember anything that would cause concern. I was very deliberate and meticulous in the cleaning process. Every piece cleaned and inspected.

 

2.9 on both primaries? thats a fail but again check your buddies it could be the meter.
when i say pick u p coils I am not talking about whats under your gas tank. and you mean 21 k ohms correct?
the pick up coils are on the crank where you wrench to check your valve specs
pick up coils are 650 ohms +- 20%

 

seeing you think your carbs are all set
checking the ignition follow this flow chart as if you fail on each step except with replacing coil pickups and tci
starts with cleaning all connections, battery voltage and condition (also check your charging system)



i gotta go

 

Yes. 21K ohms ... my bad. Pickup coils are at 626 ohms and 626 ohms

 

From the Information Overload Hour: http://www.xjbikes.com/forums/threads/the-information-overload-hour.27544/

Make sure the compression gauge has a Schrader valve in the hose that screws into the engine plug holes.

- COMPRESSION TESTING:

Yamaha recommends that you perform a compression test every 5,000 miles or so, and that you should record the readings, per cylinder, for future comparison and evaluation. The acceptable readings (specified at sea level) are as follows:

To do a compression test properly, you should first make sure all of your engine valves are properly adjusted to their recommended clearances, as valves that are too "tight" (not enough clearance) will allow the intake or exhaust valve to be open more than is necessary, or at the wrong time within the compression stroke cycle, thus bleeding off compression that would otherwise be developed.

a) make sure the engine is cool/cold.

b) remove all spark plugs, and then stick the plugs back into their caps and make sure the plugs are grounded to the cylinder head (or even better, disconnect your TCI unit).

c) remove the airbox filter lid and the air filter.

d) make sure the battery is FULLY charged, and remains so throughout the course of these tests!

e) open the throttle FULLY and keep it open during testing.

f) crank the engine over until the needle stops advancing.

g) Let the starter cool down for a minute or so, then do the next cylinder, etc.

h) If the readings are below spec, then shoot about a teaspoon amount of motor oil into each cylinder, crank the engine over a few revolutions with the starter (to spread the oil around), and then re-test each cylinder using the above procedure.

i) now re-install the spark plugs, let the engine warm up to operating temp.

j) re-test as above (plugs out and grounded, throttle wide open, etc.

k) compare the two results and analyze.

l) keep all of your figures, and note the date and mileage from your odometer, so you can compare the next time you take readings (every 5,000 miles or so).


The specified compression pressures should be:

550 engines:
Minimum: 100 psi
Standard: 121 psi
Maximum: 135 psi
Max. variance between lowest and highest: 14 psi

Maybe you can borrow his carbs if your compression numbers are good.

 

my apoligies long day but 550 manual only states side to side level , Mikuni carbs . i guess they assume you are working on a flat surface.
the carbs are mounted on an angle and when you go up on the side stand even more so.
the gas will all ways sit level in the carbs front to back in relationship to earth. my thought is to be consistant where you measure it in relation to the carb lip because that is done from side to side so the point s of referance must be on the same plane

 

Compression test complete:
1: 120
2: 121
3: 120
4: 120


Now that I've testing the ignition system and ran the compression test it looks like I'm headed back into the carbs. Before I break the rack down (again!) I want to get a good list together of things I should be looking for. Here is what I have so far:

Emulsion Tubes - Remove and ensure there are no blockages
Enrichment Plunger - Pay particular attention to. Look for deformities or damaged parts
Throttle Shaft Seals and Fuel Transfer Tubes O-Rings - Replace and lubricate
Inspect Needle Jet - Look for damaged parts or shims
Fuel and Air Jets - Double and triple check the part size and installation location
Float Height - Double and triple check float height

Things that were replaced on the last carb rebuild (~6 months ago):
Float Bowl Gasket
Float Needle
Float Needle Seat w/ O-Ring
Pilot Mixture Screw O-Ring

Are there any other rubber pieces that I need to replace? I want to start with that before I start replacing metal pieces.

This go around I am going to try and take pictures of everything so that you guys can help me figure this thing out!!

THANKS FOR ALL YOUR HELP SO FAR!!!!

 

Don't know if the Mikuni's have screens in them, but even if they do I suggest adding an inline fuel filter. Also, when you wet set the floats be sure to get any bubbles out of the line or you'll get an incorrect reading. I shake my carbs a little just before taking a fuel level reading. Finally, I suggest that once you have the floats set you leave carbs sitting for a while with the fuel supply hooked up and then take another look at the fuel levels to see if there are any needle valves with a slow leak. I had that happen.

 

Thanks for the advice! Yes, I do have an inline filter installed (no screens on my Mikunis). When I get back to the "wet set" stage, I will be sure to give a little jiggle.

 

Good compression numbers. Add to your list: Replace the fuel rail o-rings.

Gary H.

 

do you and your friend have the same size sprockets, front and rear? and 1.4 to 3k, i'm thinking you can't really expect too much from any in-line 4, even normal riding the clutch isn't out till around 2k and things don't get interesting till after 6k on a 550. the only thing 1.5k is for, is to get you to 3k and don't expect much else.

 

Your plugs are sooty and it runs worse when you add enrichment with the choke lever. I agree in that it sounds like you are running rich.

It's not your bowl levels. They look fine.
It's not your jets or valves. You have verified they the correct sizes and are in spec.
It's not the O-rings between carb bodies. They won't make you run rich.
It's not your throttle shaft seals. They won't make you run rich.
It's not an ignition problem. That won't make you run rich.

You say it starts with no choke and runs worse when you add choke, so try this... Disconnect the choke cable completely. Start the bike, and then press down on the choke linkage in a direction to CLOSE the choke(s). Push each plunger down with your finger to make sure it's bottomed out in each carb. Take it for a spin with the choke cable completely disconnected. Does it get any better?

Also, when you had the plungers out, you can see the "business end" is the small elastomeric donut seal swaged into the tip. On the pic you posted earlier, you can see the dent in the sealing donut where it has been pressing against the carb body for all these years. I know it's a reach here, but maybe you didn't get the plungers back into the original holes and some of them aren't making a good seal anymore even though they appear to be all the way down? Maybe they are bottoming out on the brass portion before the sealing portion makes contact?

Like I said, I'm reaching here, but it sounds like you've got all the basic stuff covered.

 

https://drive.google.com/file/d/0B47oYEUgDxqfOXlEOVRBb1YwQ1k/view?pli=1
is this the right o-ring? it looks kind of "fat". did it come from xj4ever?

 

Good eye. It does indeed look fat (wrong size), or swollen from carb cleaner.

 

the screens are attached to the top of the float valve bodies, you have to pull them out to see them.

 

It looks more than fat, it looks morbidly obese.

That o-ring is actually the bowl drain screw o-ring. Some mfgs. include them in their "lower end rebuild kits" and don't tell you what they are, and people assume it's the mixture screw o-ring.

The mixture screw o-ring is tiny, not much bigger in OD that the washer that sits above it.

 

It's not the oversized O-ring on your idle mixture screw. That won't make you run rich.

I'm not saying it's something you shouldn't address when you get a convenient opportunity, but it's not what caused you to start this thread.

 

It sure the hell will. That o-ring is preventing the needle from being able to come anywhere near the needle seat. Bigger gap = richer mixture. I'd guess that he's the equivalent of 5 turns out when he feels the needle bottom out on the o-ring, maybe more.

 

Not from XJ4Ever ... from the local yamaha dealership shop. Definitely worth replacing. Great eye!

Oh yes, I replaced these screens on the last rebuild along with the float needles.

Another thought ... I was scanning through the catalog getting ready for my next carb odyssey and I came across a copper shim washer that sits below the main jet. For some reason I feel like that was missing in my carbs. Going to verify when I pull the carbs. Another possibility!

Feeling optimistic again!

 

YOU GUYS ARE GONNA LOVE THIS!!! POLOCK GETS A GOLD STAR!!!

First, I wanted to verify that the copper shim washer was indeed in place beneath the main jet ... it was. No problems there.

Then, I investigated this issue of swollen o-rings! Take a look at the pictures:

https://drive.google.com/open?id=0B47oYEUgDxqfVlZudFpFbEM0WXM

The o-rings that I installed during the last rebuild (~6 months ago) were purchased from the local Yamaha Dealership shop. When I removed the pilot mixture screws this afternoon, 2 of the o-rings were mangled. One of them was so big that it worked its way over the washer and up onto the spring. Wow!! Of course there was probably fuel just spilling through that orifice with no seal from the o-ring.

Now the question is ... how much of this stuff should I replace. Obviously the o-rings, but how do the washers, springs and screws look to you guys. Is this normal wear and tear or should I just go all in on replacement parts?

https://drive.google.com/open?id=0B47oYEUgDxqfWl9wVU9MRGdsblE

 

start with the orings, springs should be ok , would be tough to ruin a washer. you may want to measure your springs and compare to new, but you were not overtighting them they should be fine. i cant see your photos you can upload them directly to this site.
unless your screwdriver slots are junk or threads deformed reuse the screws oem are durable. it all depends on how far you are in the cleaning process on what you should do or replace. if you do not mind spending the money go full new assembly it would rule them out completly.
when i went to the yamaha shop for a valve shim they told me they did not have any 29mm thick, not going back there again.

 

Told ya! +1 Polock and everyone that offered advice.

Gary H.

 

I never doubted you. Gary what's your take on how much of the Pilot mixture screw assemblies I should replace? Did you see the photos?

 

No worries...it wasn't about doubting anyone. See the collective thought regarding wrenching on these bikes starts to get a bit uneasy when together we can't find the problem and a solution(which usually happens rather quickly). I think we were headed that way. You too are a member of the collective. I agree with the advice already given for the replacement parts. I can't see the pics. Load them directly as 550 stated.

Gary H.

 

Check them out!! See the oring on the spring. Yikes!

 

Now that we're seeing things...I'd go ahead and replace the springs and washers too just to insure there will be no hang ups during the running synch. Clean and save those tho.

Gary H.

 

Completely jumped the washer and got tangled up in the spring... Now there's a possibility that I hadn't considered. Glad you looked into it despite my belief that it was a red herring. Let's hope that's the only remaining problem and new O-rings will take care of it.

So the carb that was behaving "normal" on the colortune. How did the O-ring in that carb look? Was that one of the ones that had gotten tangled up in the spring or was that one still in the correct position?

 

Polock got a bucket of gold stars..............send cash!

 

I think the real problem occurred when that spring got hungry for a donut! It really ate that effin' thing!

 

UPDATE:

So today, I received the parts I ordered from Len ... installed the new o-rings, washers and springs (same screws). Started the bike ... NO IMPROVEMENT! Put in my Colortune plug and tried to adjust, but the screws were difficult to turn (hmmmmm....). Later, my friend came over with his XJ. I asked him if I could install his carbs on my bike to troubleshoot. He agreed. After installing and adjusting the idle speed, my bike ran better than it ever has (on a short ride ... not sure how it would do on a longer ride.) This made me think that my issue is DEFINITELY in the carbs. So after I removed his carbs from my bike, I did a side by side comparison. This is where things get interesting ... here are some more ideas:


1) The fuel level on his carbs is almost identical to mine ... I think we can officially rule out fuel level. (Picture attached)



2) My carbs don't have the metal plate/shield that sits below the bowls. Could heat from the engine be transferring to the carbs and effecting the mixture? (Picture attached)



3) Our Main Jets are different. They have the same number (112.5) but his is larger than mine. The orifice looks the same size, but I'm wondering if I have the incorrect Main Jet and the Jet Needle is not seating properly, contributing to a rich mixture. See comparison photos:

 

UPDATE -- Part 2

4) Our Pilot Jets appear to be different. I tried to remove one of his, but couldn't (so could not verify the numbers). It looks as if they are different sizes (his appears to be a bigger opening). See comparison photos. Also, there is a photo of my Pilot Jet. Does this look the same as what you guys have in your Mikuni carbs? I'm beginning to think that my PO had these carbs completely mismatched with different parts and I (not knowing any better) have just been replacing those parts with new versions of the same mismatched parts (if that makes any sense).

View attachment 17807 His carbs ... notice the size of the Pilot Jet orifice.
My carbs ... smaller Pilot Jet orifice
My Pilot Jet ... #35

 

What year/model is your friend's XJ?

 

the pilot jet has a hole in the end that you can not see when installed that is the hole you need to be concerned about.
you can use an easy out to remove the pilot jet, grind down the sides of your screw driver that you are using to remove pilot jets so it fits into the passage

that plate is a heat shield and you do need it

does the removed jet have the holes in the side? it should not, someone gave me a jet that had the same size number but the sides had holes in them not the correct part for my bike

use a different color for your photo back ground

 

His is an 81 XJ550. Based on my photos can you tell if I have the correct jets? Also, do you sell the heat shield?

 

Mine does have the holes. Now I'm concerned it may be the wrong part.

Which background is better ... the white work bench or the pink piece of paper? I want you guys to be able to see the details so you can help me figure out if these parts are correct.

 

That is the not the correct style for your carbs.

We should have a good used one, drop me a note if you want it, but.......although they are nice to have for originality purposes, they are not really necessary and makes bowl removal a pain-in-the-shield.

 

cameronleeharris
take a look at this link
http://www.xjbikes.com/forums/threads/yamaha-xj550-sitting-for-10-years.69473/page-2
you will see what your main jets should look like as well as the emulstion tubes that need to be claened

 

Haha! Sure they are... That'll teach ya!

So did you get the correct jets installed yet? After five pages, I'm wondering if you finally found the problem.

 

Well, the sizes were stock ... 112.5 main and 35 pilot. Didn't realize that there were different styles! I made a pretty big assumption that what was installed in the carbs when I bought the bike was "stock". Not knowing any different or seeing any pictures of the "correct" style, I never questioned that. Ughgh! The correct jets are on the way. I will definitely update when I get them installed.

 

I understand completely. You had mentioned before that you bought new jets and verified the sizes as stock. To be honest, I didn't know there were multiple styles either or I would have asked about that. I guess I've only ever bought jets from Len and he knows the right questions to ask.

I'm just hoping that you've found the biggest issue now and can get it running better. Wrong style jets are a biggie.