need help with my '77 xs650 Not idling and blinkers stay solid

legendary yamaha

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I bought a xs650 couple months ago as my toy, and since then I have been playing around always trying to fix and repair but lately it wasn't going very well.
Well where to start:
When I bought it it was running fine and idling fine.
I noticed it had rust problem in tank so I took out the tank, did the apple cider vinegar for the rust, it worked great after 2 days the tank was looking like brand new inside, so I sealed and came out very good, very happy, I replaced the petcock because the others were shot, new petcock looks great.

I saw it had inline fuel filters so i bought other ones, replaced one was working fine, the other was standing kind of horizontal and the gas was not going to the carbs, so removed and used the old one, worked fine.
After couple of firings, when the bike warmed it started idling at 3k, I looked at this forum and most cases were the ATU springs, bought a pair from MikesXS and replaced, not to hard to replace so that was done.

This is where the "fun" started, I fired the bike, and noticed a click after every 10-15 seconds, looked at the carbs and saw that when was making that noise it was smoking from the airpods, so I thought maybe because gas drooped on the pods while working on the filters would cause that but I knew it wasn't the case just bought new airpods, removed the old ones and fired the bike again and the smoke from the carbs continued every 15 seconds. I turned off left it for couple of minutes.

When I fired back on the bike start running only on choke and not idling anymore, so I tried couple of times on and off, but no luck it was not idling anymore and runs only on choke.

At this moment:

I have removed the carbs, because red that most of the cases is the pilot jet, but I need some advises before I open the carbs because I don't want to make things worse.
Things i noticed on the carbs is that the parts in the pic "have no idea what the name is" circled red are not lined up, maybe they were set up that way.

Also I'm trying to connect led blinkers because it didn't had any but they turn on and stay solid.

SO MY QUESTION IS:

Do I need to do carbs cleaned related with the idling issue??
Or do some have any idea what can it cause that??
"if Carb job needs to be done, what kit should I choose, if you have any link would be great"
Have seen some kits online but none of them has the same jet
Main jet #117.5 Needle jet Z-8 Pilot jet #25 this numbers are taken from yamaha manual service book.

For the blinkers, what type of flasher relay should I chose to replace in order to make the LED work.

Thank you in advance,
Any type of help or advice is greatly appreciated

Best Regards

-Legendary Yamaha
 

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@Team Junk thanks for responding, That is my question, how do I get a rebuild kit with jets that fit on my carbs, because couple of kits that I saw had #130 or #140 main, #27, #28 pilot.

Any name or brand for the flasher?
Saw that ep-34 works, but not sure.
 
Most of the rebuild kits are junk. Just clean the original parts according to the guide. In particular do the slide test to check the rubber diaphragm on the slides. First thing is to figure out which carbs you have. What year model is the bike?
 
Read through the carb guide and do the tests. Could be air leaks around the carb spigots or the slides hanging up.
 
If it was running good before you should not need any parts. The rebuild brass parts sold in kits don't look so good and the orignal parts. Looking at the picture of your carbs If the brass butterfly valves are what you are referring to as not being equal, the screww between the carbs is what adjusts the butterflies.
 
the majority of rebuild kits are either incomplete or they are not suitable for your carbs. Most dealers haven't a clue which kits are required for which model carb set so they sell them as suitable for all which is often not the case.

These carbs need comprehensive and meticulous cleaning and setting up or you will have all sorts of issues .

First of all tell us the model year of your bike and give us a picture of the air filter side of your carbs so that we can identify the carbs and advise what jets should have been fitted

There are numerous video guides on youtube which you might find helpful
 
Rebuild kits are not recommended and besides, as you've seen, nobody seems to make one with the correct jets for your carb set. A "rebuild" consists mostly of a thorough cleaning. You only replace any parts than may need to be, but if you're careful, that shouldn't be many. There's only one o-ring in your carb set, on the needle jet, but it usually isn't included in rebuild kits. For floats and float needle and seat assemblies, it's best to use originals or at the very least, genuine Mikuni replacements. Genuine Mikuni jets are best as well. Any rebuild kit would contain aftermarket knock-off parts, sometimes of questionable quality.

Yes, you have BS38 carbs, but there were no fewer than 4 different sets used on the 650. Since yours are a linked set using one throttle cable, that narrows them down to one of the two later sets. They could be the correct '76-'77 set for your bike but they may be the later '78-'79 set as well. You have to positively identify the year of the carb set because the jetting is based on that, not the year of the bike you're putting them on. There are several visual "tells" you can use to I.D. the year of your carb set. A '76-'77 set will have drain nipples on the bottom of the float bowls .....

TxUZ73r.png


..... and a '78-'79 set won't have them, just a blank spot where they used to be .....

mv4p1Rc.jpg


On the bodies, the big "tell" is the location of the air vents for the float bowls. On the '76-'77 set, they are external, hose nipples sticking out the inner sides of the bodies. On the '78-'79 set, they were moved inside and are along the edge of the intake bell at the 3 and 9 o'clock positions .....

3mQOwp3.jpg
 
legendary yamaha, 77 is a very good year to work with in my opinion.
We can see your bike pics in your “Icon” image there ?
Post a nice big pic of that bad boy and maybe you’ll catch some more attention of members off rambling lol
Welcome ! -RT
:thumbsup: :cool:
 
the majority of rebuild kits are either incomplete or they are not suitable for your carbs. Most dealers haven't a clue which kits are required for which model carb set so they sell them as suitable for all which is often not the case.

These carbs need comprehensive and meticulous cleaning and setting up or you will have all sorts of issues .

First of all tell us the model year of your bike and give us a picture of the air filter side of your carbs so that we can identify the carbs and advise what jets should have been fitted

There are numerous video guides on youtube which you might find helpful

I will do so, as soon as I go home, because I'm at work and don't have any pic of carbs on my phone
 
Here's a stock jetting spec chart I drew up. As you can see, each of the 4 BS38 carb sets are jetted differently. This is why you have to know what set you're working with .....

7wbHkpb.jpg
 
Here's a stock jetting spec chart I drew up. As you can see, each of the 4 BS38 carb sets are jetted differently. This is why you have to know what set you're working with .....

7wbHkpb.jpg
I don't recall I remember if they had the drain nipple at the bottom, but 90% sure they have it, so 90% sure they are original for the year, but noticed they have been worked on them before so not sure how original will be inside
 
legendary yamaha, 77 is a very good year to work with in my opinion.
We can see your bike pics in your “Icon” image there ?
Post a nice big pic of that bad boy and maybe you’ll catch some more attention of members off rambling lol
Welcome ! -RT
:thumbsup: :cool:
Yes, that is my toy.
 
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