cant get my idle

I was able to take the carbs off bench sync them using the holes in the carb which gives you a much better bench sync then anything else I've tried. Thanks polock and fitz.

Hooked it all back up went to sync them and got them all within 2.5 lines on the Morgan carb tune. Pretty close. I didn't want to leave the yics tool in 2 long. So I shut it down.

Took the yics tool out and hooked everything back up to c how it ran. Idle was a little high. Turn it down. Idling right at 1200. Fingers crossed and it slowly started to creep back.

Here's where it gets interesting... When it put the screwdriver on the sync screw with a little pressure it came back down. Binding carbs???? New seals all around with silicon grease on them all. The carb were level all the way around while I was putting the rack back together. So i don't no why they would b binding or how. And if they were binding would that make the rpms creep up?

Now do I go back and check to throttle shaft seals make sure there all good. Or go back and try to get the bike perfectly sync????

Thanks again everyone.

 

when i had my carbs squeaky clean they did something like that, the weight of the screwdriver would change the sync. try this, bike off, open the throttle all the way and let it snap closed a few times, listen to the sound they make, now get a little oil on the springs for the throttle shafts, the sync screws and the little plates the sync screws push on. now listen again for a change in that sound. your listening for the thunk to change to a thwack,
try to get the sync perfect before you go back into those seals.
here's another thing. i'll most likely get some flack over but try to sync them without that yics tool in, works for me.

 

You won't get flack off me, bro.

 

Once again, Mr. P. has nailed it. You've got a slight bind somewhere; you need to get all of the linkage parts to "settle in."

Inspect the whole rack very carefully. All of the linkages and double-spring "sandwiches," the return springs, the various tabs, etc. You may have a return spring binding on its linkage or something just slightly out of position, a tab or the end of a spring rubbing where it ought not rub, etc.

Using the Morgan, you should be able to get them to match perfectly.

Being as they're Mikunis you don't want to go through the whole butterfly screw thing again, I'd hold off tearing into them to revisit the seals.

And I'm not going to rehash the YICS tool argument. Science is science; it isolates the cylinders so you're dealing with them individually. Whether or not that is an advantage when tuning is the only facet that can be debated, and Yamaha seemed to think it was.

 

Valves in spec...
Carbs clean... (three times)
Floats wet set at 2mm below the bolws. (ten hrs all perfect)
The only thing thats not new on the carbs are the air box to carb boots. Pass the propane and wd40 test.
Proper bench sync as well. Many times.
I'm at the point where I can take everything apart put it all back together and bench sync with my eyes closed. No joke. 8 months of going through this.
But not gonna quit.
Turned to the manual and performed everything matinence related. Except my front brake. Which why should I do it if the bike dont run right anyways. Lol.
Tried syncing with the Morgan carb tune which I was able to get everything in sync. (with the yics tool blocking the yics and without).
Still runs like crap.
I've tried everything that everyone has said and more and multiple times.
I don't have a float level tool but if I get the fuel levels all the same with the clear tube method they should be good right??
Really I'm running out of ideas. I'm starting to think about going through the electrical system (which looks good). Could anything with the electrical or exhaust system cause a hanging idle?
It only want to idle at 1000 or above 2000rpms.
Thanks for all the help everyone I'll keep at it. But at some point I might have to turn to the M word. (mechanic). So I can waste some money that I don't have for someone that doesn't no what there doing... to tell me THEY DON'T NO... Lol
Ps. New plugs and caps from Len. Cut the wires a 1/4 inch back as well .

 

Well called a mechanic 50$ he comes over and weather it takes 20 min or 8 hrs and if he can't fix it then it's free. He said he's booked for the next 4 days. Good sign??? Guaranteed he's not a xj mechanic but seems to think something's up with the carbs. what's there to loose 50$ and he fixes it or I pay nothing have have the same problem.
Any thoughts.

 

The Lady next-door to me is a Witch.
She says she'll remove any curses on the bike for $75.00
She's booked 'til after Halloween.

 

Thoughts?

I dunno, want a broken float pillar or two?

"He's not an XJ mechanic." No kidding. He won't fix it and could very well do damage.

Personally, I think it's a bad idea and I wouldn't let him touch the bike. You know more than he does at this point.

You're either not in sync, have a vacuum leak (did you change the little rubber vacuum port caps?) or the float levels aren't properly set to spec even though you think they are OR you've got leaks between the valve seats and the carb bodies (new o-rings there?)

Pilot screws removed, new o-rings; all passages flushed and all set at 3 turns out?

You took the carbs completely down, removed the butterflies and replaced the throttle shaft seals?

HAVE YOU DONE A COMPRESSION TEST ON THIS MOTOR? If not, do so and report back.

We'll figure it out. Don't pay some numbnuts to F* up your bike.

 

Like Fitz said, you know more than a non-XJ mechanic....this guy will probably try to get you for some money whether he fixes or not......be leary of him....I am in San Diego in the La Mesa area.....you and I are XJ mechanics.....self taught from a lot of advise from here.....

Cancel your appt with this guy.....this guy was probably standing on the median yesterday panning for money.....

LOL

 

Remember too, you can vacuum sync it to within a silly millimeter and a bad float level or a misbehaving pilot circuit can imbalance it. A truly good sync is a combination of vacuum and mixture synchronizations; one cylinder too rich or too lean can hang your idle even if the vac sync is solid. And a float can bite you if your pilots are fine. Or vice-versa.

In my own case it was float levels that needed to be revisited...

 

XJrider92117,

You can upgrade to my Xj750 Maxim when I get it running.....j/k....when your bike & mine is dialed in....we will have to take a ride up to the Laguna Mtn's ....what do you think.....a pack of 2 bikers......no wheelies on sidewalks , no brake checking in front of SUV's.....just a fun ride up to the local smokies....

Hope you get it dialed in soon.....I am almost there...about a month away for me...maybe...

 

oh yea, carbs. Pilots, vac sync, float. got a total of 50 miles on my beast and all in diagnostic miles. Hopefully Jan, feb, and march will give me the time to tear my carbs aprt and re-do last summers disaster.

I wanna be a rider not a mechanic ..... guess what, I'm doing nothing but mechanic work.

Maybe the bike gods with help next summer.

 

Rick if I still can't figure this out after Halloween I may need the witches #.

Well I've been talked out of the machinic...

Carbs are already off. I will revisit the the fuel levels.

Question... If my fuel levels are in spec and all the same then all my floats are all the same correct???

Vacuum caps new pilots screws removed and oring replaced. New throttle shaft seals. Fuel rails oring as well.

Dmlyster... I feel you man.

Five... It's almost winter don't we have to put the bikes away.... O wait. We're in sd and its 70 degrees all winter long. Just gotta watch out for 10 days of rain that will be coming at some point. All jokes aside a ride is kinda far from my mind you sound closer than I am. But YES at some point a ride would be cool.

Thanks again everyone will report back.

 

can anyone enlighten me on this little tab. Its on the right
hand side. When the floats fill up this litte tab sits on the float pillar. I cant find any info on it. Still messing with fuel levels. When i bend the tang arm it doesn't seem to change anything. Any info would be great.

Thanks

 

that little tang stops the floats from going down too far and getting stuck down there. they come into play if you ever run out of gas

 

I have the same issue of reving to 3000 rpm and slow to idle down, but I havent replaced the seals yet. They are on the way. Hope you resolve your issue.

 

Nothing at all wrong with that, but a 30 year old bike wouldn't be the way to go. Anyone who just wants to ride should buy late model bikes.

http://www.xjbikes.com/Forums/viewtopic/t=14581.html

 

The thing is, if you're willing to put forth some serious effort and are very thorough to begin with, you can "just ride it." Within 1980's parameters of course.

Yes, there is maintenance that needs to be done, like any high-performance machine. But checking the valve clearances every 5000 miles, changing the oil and filter, and feeding it tires and sparkplugs on occasion is about IT if you did a proper recommissioning.

Done, right, it's like having a new 198x Yamaha. Lots of riding, very little work.

But you do have to sink a lot of time and effort into it up front. Otherwise it becomes an ongoing battle, which isn't any fun after very long.

And if doing it right means your skillset needs to expand, what's the harm in that? I've been doing this for over 40 years, and I'm still learning new things in the process.

 

Basically your born with it or not. Sad to say many people aren't. Especially if this is your first go around. It can be frustrating. This is the first bike (besides a dirt bikes) that I have ever worked on. It can be challenging the first time I took apart the carbs I was a little nervous. But I got it all back together which most people that were around to see them apart said I would never get them back tegether. Well I did and it's runs. The same people said the same about valves. Did it which was pretty easy after you get the tool down. If you dont want to do the work buy a new bike they'll do your oil charges for you as well. When you need some real matinence done to it you can park it on the side of your house for the next 25 yrs...

but enough about that...

I talking fuel levels...
Here's what ive been going off... http://www.xj4ever.com/setting%20fuel%20levels.pdf
Any tips shoot them my way...
And I have the ruler if anyone was curious...

Anyone ever get air into the clear tube when measuring the fuel levels?
I put a golf tee in the vacuum line from the petcock I think that stopped the air bubbles that were getting into the line but not sure. And a golf tee in the clear tube until I crack the drain plug.

 

I question that statement. I think some people are more developmentally directed towards mechanical tinkering, but it's a skillset and can/is learned. Certain brain physiology is helpful, such as the spacial reasoning that is arguably stronger in males than females (studies still aren't definitive), but as a skill it's still about the time spent on it. Anecdotally, I'm a perfect example...knew bupkus about bikes mechanically a few years ago and now I'm competent, thanks to this site and the members as mentors.

I don't disagree that some people aren't interested in that, which is why I say if you just want to RIDE and not be involved with the bike mechanics, these old bikes aren't the way to go. Life is pretty short, so it pays to do what you enjoy doing with your free time before you become worm food.

Unless you're lucky enough to live next to Fitz tho, I hear he'll rebuild your bike for beer. Or was that Eco?