83 Yamaha XJ 550 SECA First Bike Woes

Hello Everyone! I'm new to this forum, seems like theres a TON of info in here and some VERY smart people so I thought I would start a topic to try and pick yalls brains a bit while I go through the rebuild process. This is my 2nd bike ive ever had, First one in almost 10 years, and I haven't worked with Carburetors for over 13 years so I've forgotten most of the little I did know/learn from back then So, the bike is in pretty good shape. 14k Orig miles, wasn't sure if it ran when I bought it, but for $500 I knew it was going to be a project! All the plastic is there! both side pannels, rear fender, even the (dorky looking) front fairing! Although that front fairing did have some damage so I took it off. Looks much better now. This bike is going to be an ongoing process. It needs a LOT of work, Front brake issues, throttle cable is kinda questionable, but for now I just want to get it to IDLE! Right after I got the bike I ordered a set of carb rebuild kits, Cleaned out the carb pretty well and replaced all the gaskets (one carb didn't even have a float bowl gasket on there! Another had a cracked one) Replaced the float needles etc... put the carbs back on the bike (no I didn't break them apart..didn't want to bite off more than I can chew trying to relearn carbs again, taking it slow, trying to be thorough) The bike started! So with $600 into it including the purchase I had a bike that would run, but wouldn't Idle. Then I read (on this forum) one of the problems/symptoms so I pulled the carbs off and took out the... uhhh.... Engine Side adjustment screws on top of the carbs (you know the ones, down in the little hole...) and the jet under the diaphram (correct me if im wrong, I dont have a schematic in front of me and my memory is kinda bad...so I dont remember their actual names atm. lol) Those were pretty gunked up, so I cleaned them out, put the adjustment screws back in seated them and backed them out 2 1/2 turns. While I had the carbs off the bike I also looked at the floats and dry checked the float heights, All were very VERY close and right at about 20mm from the top of the float to the gasket (well seated) So after all that was done I put her back together and started her up! With Full choke she revs up to 5k rpm after starting, Lower the choke and it drops rpm quickly, but once it hits 3k RPM it REALLY wants to die. After fighting with her to keep her from revving to high but stay running I got it to Idle... Kinda... Without the choke the RPM's are ALL OVER the place, and it hovers around 3k rpm. I Adjusted the Idle Screw to drop it down and it wants to die. I can keep it alive with the Throttle, and the throttle IS responsive, and it revs up fine, and I can keep her running with a few blips of the throttle but it will not Idle on its own at all. I'm just guessing but it kinda seems like its running lean, and I dont wanna burn anything up so I put her away for the night. I figured after cleaning the carbs, adjusting the floats and all it would at least be able to Idle. Any Suggestions on where to look FIRST to try and get her to idle on her own? Any suggestions on where to start looking would be great! (Also, i'm still new to these motorcycle carbs so pictures are worth 1000 words... you know ) Thanks guys and I look forward to talking with all of you!

 

Hey! Congrats on getting an xj, if you're patient and listen to the wealth of knowledge the members on this site offer you will have that bike purring in no time.
Start with the main things.
Valve clearances
http://xjbikes.com/forums/threads/airhead-valve-adjustment-with-pics.14827/
And
http://xjbikes.com/forums/threads/airhead-valve-adjustment-part-2-the-tool-vs-ziptie-w-pics.29209/
Once they're in spec do a compression test to make sure you're all good.
Then you'll need to really revisit your carbs. If you follow the church of clean you'll only need to clean them once and know that it isn't an issue short term.
http://www.xjbikes.com/forums/threads/in-the-church-of-clean.14692/
Also a ton of good info here
http://xj4ever.com/catalog/info.html

Keep in mind before you ask a question you think may have already been answered, hop over to Google. Type in "site:xjbikes.com (insert question here)"
It is a more accurate way to search the site.
Good luck!

- EM

 

I was going to work on the valves later today! I am skeptical though, on the valves being whats causing the lack of idle, RPM's Hanging up when revved, and the ridiculous "bouncing rpm's" when I do get it to sit at 3k idle (lol, that just sounds so wrong... ) But im going to do them anyways, even if its not the primary cause. I have read through most of the "Church of clean" article ive seen and I think I went to the "Bible study of clean" lol. Not as elaborate or meticulous as the church of clean article but it was in really good shape when I did tear it apart, Granted I did find a few places but I think I got everywhere where there could be something gumming up, All the important areas are clean (I know, ALL of it is important, but seeing as I would rather not take them COMPLETELY down until im familiar enough and confident enough to get them back together....plus breaking them apart and everything would require me to spend more money on a vacuum balancer, which the wife may not be too happy about at the moment.) I was thinking more of a carb issue as to the problems im having. What would cause the lack of idle below 3k rpm? What would cause the RPM's to hang up high and not want to drop back down? Also, I HAVE to use the choke to start it, and if its not warm I have to keep partial choke just to keep her running. As soon as the RPM's drop below 3k she just dies. I know it could be several things at once causing this problem but I'm just looking for where to START working first in order to get it to Idle. Could improper fuel levels in the float bowls cause something like that? I expected the floats to be way off but they weren't.

 

Valve clearances are a must do. Many bikes never had them adjusted and all carb tuning efforts will be for nothing if they are out of spec.

Bad throttle shaft seals can play havoc with your idle and the rack has to be broken apart to replace them. It may seem daunting, but I managed to do it with the help of the church of clean. Just remember to take lots of photos and keep everything neatly organized with the corresponding carb.

You can make a very cheap carb synch tool out of two baby bottles and a length of hose.

 

BigT when you did your carbs did you break the rack and do one carb at a time or do the same step on each carb.
-EM

 

I worked on all 4 at the same time. I think In the church of clean they suggest using cup cake pans to keep all the parts with the correct carb. Worked well for me. I used a punch to number the carb bodies.

I did get tripped up in two places. I put one of the butterflies on incorrectly even though I marked them with an arrow showing the correct orientation. I believe I had the throttle shaft turned 180 degrees and it would not allow the butterfly to seat properly. Took me a while to figure that one out.

I also had trouble getting the rack perfectly level while I tightened the rack screws even though I was using Len's rack assembly jig and a level. An extra set of hands could be a big help at that point as the rack tends to twist as you tighten the rack screws.

 

As a side note I believe the 550's has Mikuni carbs instead of the Hitachi carbs that I rebuilt and they require the butterfly screws to be filed off if they have never been removed. I would replace them with Allen head screws from Len, which is what I did and don't forget the loctite.

 

Thanks for the points. I'm going to be tackling mine so I'm trying to soak up as much as I can lol.

-EM

 

Yes, this is absolutely correct. And getting the alignment of the carbs done correctly is critical to having the carbs perform properly.

 

Hmmm, Where can I get the Jig you used? Im heading into town soon so im gonna have to pick up some pie tins or something. Its so far to get to town I can't just 'run to town" for anything so I gotta plan my trips. I'll add Throttle Shaft seals to the list as well, Thanks a bunch, I'm off to town! Then pulling the carbs again *sigh...* Thanks again guys!

 

HCP20990 Aftermarket carb rack reassembly alignment plate. I ordered it from Len when I got my other carb parts, it's a plexiglass plate that allows you to get the 4 carb throats level to each other and has a slot cut into it for the throttle cable bracket which tends to get in the way.

It was helpful but I would still have somebody around to help hold the rack while you tighten the screws.

 

Who is this Len person? I may wanna have a talk with him, Order up a heap of goodies!

 

Welcome to the club. Member Chacal (who replied above) is also Len. Start a conversation with him. The average cost to recommission a xj is between $600 - $800. The $ you'll save on labor and the knowledge you'll gain...priceless.

Gary H.

 

I agree. I'd rather know where my money goes and know what work has been done than blindly pay someone who won't do as thorough a job as I will. Even inexperienced I still plan to take my time and do things right.
-EM

 

Also pull the plugs, see what type they are and check the gap. Two of the ht caps have screw in resistor holders. Make sure they are snug.

Gary H.

 

Will do. Thanks guys. The plugs are brand new, gap is good. I'm about to pull the carbs off again and go through them, while they are off after I go through them I'm going to wet test the float levels and then after putting it all back together i'm gonna borrow a torch from my dad and see if there are any vacuum leaks. I appreciate all the support!

 

This is very true, and its one of the reasons I decided to get an older bike. Sure I could have bought one thats good to go, but I wouldn't know anything about it!

 

Please forgive my ignorance, I know basic functions but names still confuse me... lol. Where is the Enrichment passage? Does that have to do with the choke?

 

-UPDATE-
So I did a thorough cleaning of the carbs again, found a couple things. After taking those carbs to "Church" (minus 1 or 2 steps) I found the enrichment passages pretty well blocked, and also, the float on the 3rd carb was not free moving. It moved, but not completely freely like the others. The float pin that holds the float on was a tad bent. so I pulled out my hammer and gently tapped it straighter.. I didn't manage to get it straight enough for the float to move like the others so I ordered some new float pins. Also the float levels haven't been wet tested yet, so thats also on my list. I can't really do that until I get the new pin for the float though. The pilot screws, (on top of carb, engine side, down the hole) were all seated all the way down, not too tight though, so I backed all those out to 2 1/2 turns and she ran WAY better than before. The difference is night and day, There are still some issues, but I think most of that will be resolved with the float pin and wet testing the float levels. If not I'm going to check for vacuum leaks. Kinda hard to check for those when the idle isn't stable though

 

Any suggestions for these rubber boots on the intake side? They are stupid hard to get connected to both the air box and the carb. How do yall do it? Any tricks that would make it easier? I was planning on running pod air filters eventually, (I know I would need to rejet) and after fighting with those intake boots with no success I'm leaning more towards just getting them now and ordering the jets.

 

I've heard of some people using heat to make the rubber more plyable, so a hair dryer even would work.
It just takes patience and brute force/ignorance.
lol
Also I would suggest leaving the carbs off the bike altogether until they are COMPLETELY church approved clean. Otherwise you're going to keep taking them off and putting them back on. The more you do it the more you risk breaking a seal or (if those boots are original) they can split easy.

Keep up the good work!

-EM

 

I believe you can loosen the air box retaining screws and slide the air box away from the carbs to give you a little more wiggle room. If you do decide to go with the pods, try not to destroy the air box as they are getting harder to find and you may change your mind and want to go back to stock.

 

How to clean Enrichment circuit well

 

just letting you know if you install carbs you will be able to start bike and run it before putting boots back on. check your fuel hight with carbs on bike , bike on center stand . to check if bike is level test fuel height on carb 1 to left side of bike then bring hose to right side of bike and retest from begining. (close screw and drain hose) if it is same height on right and left good to go if not shim center stand to level bike. would hate to have to take boots off again.
with bike idleing you can do the propane test on carb to motor boots do not forget the vacuum caps and throtlle shaft seals also test the enrichment (choke) circuits .
to see what will happen when propane enters the system do a quick propane release into the intake side of the carbs.
warming boots in very hot water helps soften them install boot on middle carbs first.
push them into air box past the outter seal then slide forward to carb and work the seal out from the box

 

Heres the thing, it still wont idle, I adjusted the float evels, put the new pins on the floats so they move freely, I just can't get her to Idle... anyone want a bike? lol. I'm so frustrated, I should have been riding it a while ago... Summer is almost gone, and I still cant even get her to run on her own. Ive taken the carbs to church, messed and tuned the fuel levels.bench synced them, but it still wont idle steady. Only time ive gotten it to Idle is turning the idle adjustment screw all the way off (so itdoesn't even touch the throttle shaft) , and turning the choke on, then it purrs at 1800 rpm. im kinda sick of this thing. Ive been working on it for a while and no progress whatsoever....

 

you really have to do a running sync, a bench sync gets to where you are now. take the mixture screws to 2.75 turns out.
make yourself a 2 bottle sync tool and it should come right in

 

Theres no way i can do a running sync when it dies as soon as i stop feathering the throttle. It refuses to even try to stay running.

 

2 bottle tool
http://www.xjbikes.com/forums/threads/how-to-make-a-2-bottle-synch-tool.15650/
5 dollar tube style
http://www.xjbikes.com/forums/threads/5-carb-sync-tool.4191/

hang in there I spent about 60 hours on my carbs alone. she purrs then roars
253 miles of riding so far

 

you can run with the "choke" on at 1800 rpm? without throttle?
can you ease back on the choke a little and still run?
if so you may be able to start syncing.
it takes a while before you can turn the choke off for the bike to warm up enough to idle on the pilot jets.
did you clean the pilot jets and associated passages?

look at this link it shows how the three circuits in the carbs work more so what has to be clean,
http://www.xj4ever.com/inside your carbs.pdf
folow the color arrows and you will see where you can spray carb cleaner in and where it should come out.
sounds like pilot jet circuit is not working properly.
also did you test the ignition circuit.
are your exhaust pipes all getting hot to see that all cylinders are fireing??

 

Well now that im a little more calm, let me explain more... It wont idle at all below 3k rpm. Ive tried adjusting pretty much everything. After the bike warms up it does run smoother, but still wont idle. I can get it to idle above 3k rpm with the idle adjustment screw adjusted to keep it at 3k, but as soon as I turn the idle adjustment screw down a HAIR the rpm's drop and it dies. When I use the Choke it will start and shoot up to 5k rpm, then I turn the choke down or off and it tries to die, (unless I have the idle adjustment srew adjusted enough to keep it at 3k rpm) It also does not idle down slowly. If I rev it up it kinda hangs up and very slowly the rpms will settle down. The only way I can get it to idle below 3k is if I adjust the idle srew as low as it will go, and FULL Choke. then it idles, and the rpm's dont hang up when I rev it. THATS what im struggling with.

 

Also, theres only 2 things I haven't done on my carbs. I have not replaced the throttle shaft seals, and I haven't pulled out the Choke plungers. I plan to, but I doubt either of those are whats giving me these problems. Maybe the Throttle shaft seals, but I gotta get some first before I can replace them.

 

Pull the mix screws and the plungers because it sounds like the problem may be there. Make certain the orientation of the spring, washer and o-ring is correct and are un-damaged, the plungers are good and there are no obstructions when they seat. You should be able to turn the mix screws out just a touch to make it idle when you take the choke off. Are you certain the ec in the bowls are clear? We just had a member with this same issue.
Gary H.

 

to thine own self be true if ,you mislead us we can not help you you stated above "After taking those carbs to "Church"" ...... I have not replaced the throttle shaft seals, and I haven't pulled out the Choke plungers. did you stand in front of the church or just walk past it
this is where the carb circuits work from Talkin Tech read the info
http://www.xjbikes.com/forums/threads/talkin-tech-various-thoughts-on-various-issues.14608/
The pilot fuel circuit is active from idle up to about 2500-3500 rpms, and at about 3000 rpms the main fuel circuit starts becoming involved, and by 4000+ rpms the main fuel circuit is responsible for about 80%+ of the engine's fuel supply conditions.
to add to that your enrichment circuit is what gets the motor running until it warms enough for the engine to run smoothly on the pilot valve.

you should change your name to PO

 

+1 ^ to everything but the changing of the name bit. Let's just get this right.

Gary H.

 

yes over stepped the name thing, i will stand in the corner and not ride to day as my penance.

when you get it running make sure to do a propane test on the throttle seal if it picks up rpm then you have leaks.

 

i.e. partially or fully clogged, etc.

 

Ive gone through the pilot jet circuit multiple times. theres nothing clogged there... Heck I spent 3 hours per carb making sure those were spotless the LAST time. but it didn't have any noticeable effect. All the issues point to the Pilot Fuel Circuit, but, I know its clean. which is why this has been so frustrating. I could always take them apart again and look at the pilot fuel circuit for the 4th time, but I'm not going to find anything... Chacal, Any chance you know where I can get the O-Rings for the mixture adjustment screws? And the Throttle shaft seals? Guess ill be tearing the carbs down again. Theres gotta be something im missing... the pilot circuits are clean... maybe a weird size pilot jet or something. I would think with the pilot fuel circuits being clean it would idle, but guess theres gotta be something im missing.

 

I had trouble with getting my bike to idle, it would eventually die once warmed up. I went to church of clean and did not find anything wrong with the pilot circuit, but I replaced the throttle shaft seals and it now it idles just fine.
I got my throttle shaft seals, mixture screw oring's, and fuel rail oring's from Chacal.

 

get the bike running at 3k rpm and do a propane test on your throttle shaft seals rpms should climb if they are leaking

 

Thanks BigT. Ill get those ordered. Seeing as thats the only part i havent played around with, and sonce nothing else ive done has had an effect im guessing thats where the problem is. XJ550H, ill do that when i get off work just to make sure as well. Now to find a torch... Lol

 

you can use carb cleaner instead of propane but I do not like the flamable liquid method or spraying it on rubber parts, but it does work and it is not like you are soaking the rubber in cleaner for hours

 

sounds good. Got plenty of that laying around. Also, found out my Petcock leaks... there goes half my gas. It didn't leak before..... Can something bad happen if the Petcock was leaking a little? I pulled the carbs off and it didn't seem to be flowing out of the carbs or into the engine at all, just from the petcock itself, down the side of the engine, pooling around my kickstand. (not a standing puddle, just damp)

 

Can something bad happen if the petcock is leaking a little?

Is a fire a bad thing?

So long as the float needles are doing their job there is no wat that fuel can get into the crankcase.

 

Im not completely retarded but i should have worded that differently. I know fuel in the crankcase is bad. But what are the major problems that a faulty petcock can cause and how do i troubleshoot for said problems? And how can i figure out if there is fuel in the crankcase and what can i do to remedy that.

 

Fuel, Air and Fire. The tank and petcock provide the necessary fuel to run the engine.

Gary H.

 

A faulty petcock can provide too little or too much fuel. If there is some kind of restriction it may not allow enough fuel through to the carbs starving the engine. If the diaphragm is ruptured it could allow gas to run down the vacuum hose into your intake and cause engine flooding or a rich mixture depending on how much fuel is getting through.

I would take off both hoses while holding a cup under the petcock. You should get no flow out of either hose on "on" or "res" setting. Then turn to "pri" and you should get good fuel flow. If so then put back to "on" and try sucking on the vacuum hose to see if you get fuel flow. If not then the petcock has a problem and needs attention.

If you are getting any fuel through the vacuum hose I would cap off the petcock and the intake and just run on prime until you can get it sorted.

To check for fuel in the oil just take the oil full cap off and give it a good sniff. If you smell gas the oil is probably contaminated. You can also check the oil level in the window.

If it is contaminated just change the oil.

 

Rebuild the petcock if you haven't already, replace the vac hose, fuel line and add a in-line sintered motorcycle specific fuel filter. Len sells everything you'll need to do it right the first time.

Gary H.

 

to test petcock disconnect fuel line disconnect vacuum line remove tank . set petcock to on then put a fuel line on it into a jar and a hose to the vacuum nipple and gently suck on it, does fuel flow? do the same for reserve. if fuel flows with out sucking on vac line in the on or res. position your petcock needs to be rebuilt or replaced.
cap off fuel nipple
if fuel comes out of the vac line in any position you need to rebuild or replace petcock

 

Thanks guys. I'll test that petcock and either rebuild or replace. The Metal is a little pitted and I'm not sure how well its going to seal even wit new gaskets and such. I dont want to replace the gaskets and rebuild it only to have the new seals not seal because the metal is not smooth. Almost cheaper just to get a new one. How do you guys feel about the NON-Vacuum operated Petcocks? As long as you don't forget to turn it off it should be fine right? What happens if the crankcase fills with fuel anyways? I don't think mine is, but what kind of damage can that do? What could happen if someone tried to start it after that?

 

Open the gas cap and inspect the large black washer. If it's cracked and or damaged (it probably is) you'll need to rebuild the gas cap too. If fuel + oil fills the cranckcase the crankshaft will be submerged in it. End result if you try to run it...it'll eventually blow the motor.

Gary H.

I should have said "ruin" the motor.