Ripping my GD hair out

OK. I have adjusted valve clearances to spec. I have CHURCH OF F'N CLEANED my carbs. Thanks to CHACAL I just put new o rings, shaft seals, the WORKS. If it is rubber it's been replaced. Clunk tested, new gaskets everywhere.

Bench synced.

Attempted for 2 hrs, after riding and getting her road temperature, to sync. BUT NO. She revs high, she dies out, she's all over the map. I get her to idle right, and then look at the throttle and vrooooooooooom 6k rpms. I have spent the better part of my day adjusting little by little the idle adjust screws, then more syncing.

WTF!!!!?!?!?!?!?!!

I thought the order was, Valve Clearances, bench sync, vacuum sync, colortune (idle screw adjust). RIDE.

I am so sick of working on my bike. I would love to ride her sometime before winter comes.

 

i should have just bought a new bike.

 

oh dont say that! a new bike would be reliable and boring, personally i still think 82 and older are still pretty new...... just me.

have you eliminated a vaccum leak, sounds symptomatic of air getting in, hope you get it sorted out

 

+2

 

Bad intake gaskets, cracked intakes or clamps are not tightening right. Any air leak will cause that.
Most importantly did you wet set the float levels with the clear tube method?

MN

 

ok. So before I tell you why I'm an idiot. I'll tell you all the things I DID do and check.

Valve Clearances. Check
Church of Clean Check
Float Levels. (clear tube on all 4) Check, check, check, check
Boots from Carbs to intake Check
Boots from Airbox to Carbs Check
Checked for leaks around the "hats" on the vaccuum ports on boots Check
New Throttle shaft seals Check
New Fuel rail Seals Check
New idle mix screw seals and washers Check and check
Home made Manometer Check
Proper Bench sync Check

As I made haste to beat the thunderstorms, which never arrived, I forgot one... minor... thing.

Staring me in the face, LITERALLY the whole time.

YICS.

YICS..

Might want to vacuum sync with a yics tool actually IN the YICS chamber...

**facepalm**

I put my YICS tool out of sight, therefore, out of mind. The WHOLE time YICS on the valve cover was probably laughing at me.

It is too late now, as my neighbor has twins, to check to be sure that this is the issue... but i'm going to go ahead and guess that it is.

Way to go STOOPID

 

for whatever reason it just jumped into my head on the way home from the store...

I could've been riding right now.

But just wait for tomorrow's rant if this isn't the case.

Plus I do still need to colortune. Right now all idle screws are sitting at 2.75 turns out.

 

ha ha (laughing with you) i think everyone on this forum knows exactly how you feel...... long periods of joyful riding punctuated by moments of terror and frustration.

well the problem is usually staring you right in the face i know as well as anyone.

but tomorrow before you go ripping around on your perfectly tuned piece of two wheeled perfection...... i think you owe her an appology for that awful thing you said about shoulda got a new bike

enjoy the sunday ride

 

well i did just buy her some new shoes...

 

"Might want to vacuum sync with a yics tool actually IN the YICS chamber..."
not really necessary

 

so what you're saying then is that i'm still screwt

 

ok then look. Tomorrow I'm getting up extra early. I will try to sync with the yics tool. If that doesn't work, right away, I wll go back to the beginning and will follow these steps. and report here my findings. from square 1


I will check again, my clearances.
I will then again check my float levels
I will then check all moving parts on the carbs
I will then check, after installing and bench syncing, for leaks with ether
i will then RE-attempt a vac sync

And if it doesn't work... i will then attempt to drop it off at the dump.

If it does work, i will try my hand at a colortune.
Does one colortune with, or without the yics tool?

 

Hold on there. Been there done that with how you are feeling. But don't let yourself get pushed by the situation. You have just put in an amazing amount of work! All that would have cost a mint to have a shop do, and YOU DID IT. So now that bike is worth a lot more than it was.

Do yourself a favor and step away when you get to the WTF!! point as it will not serve you. I had a computer that kept crashing and I replaced or fixed EVERYTHING on it (or so I thought) but it would still crash. Only thing I didn't replace was the F'ing mouse and yep it was causing a short!

So to your issue it can be solved. Do the YICS blocked synch anyway as it is the proper method and otherwise you can't match them. Somewhere air is likely getting in and it is possible that you won't be able to detect it with ether, propane would be better but still not foolproof. What do your plugs look like when you pull them? What were your compression #'s?

Murphy's dang law is in effect and I'm betting Rick would have some choice advice for you but he is going under the knife. Just don't give up.

Oh and the new bike being better theory..well hell yea until it something goes wrong and then you can't work on it, and it will cost you as much as a used XJ to fix.

 

I feel your pain- Just hang in there- once you get this figured out it will all be worth it.

 

One more set of crossed fingers on your behalf. There aren't any new bikes out there with the pure character of these things!

 

+1 on air leak check around intakes - it's reported that the gasket can degrade, then you do a messy job of sealing the perimeter with RTV.

You CAN check float levels on-the-bike by propping the front up by about a foot to level the carbs - may save you some time.

I wouldn't think you would have to double-check your valve clearances -

Good luck !

 

-valve clearances shouldn't need to be re-checked if you did them right.

-float levels ARE critical, any less-than-accurate settings will drive you crazy.

-instead of using a "feeler" of any sort when you do the bench sync, use a different technique: adjust the butterflies relative to one of the tiny bypass holes in the top of the carb throat. It's much easier to SEE the relationship between the butterfly and the tiny hole than it is to accurately gauge "drag" on a feeler. (Thanks to Polock for this method.)

-You're probably OVER-adjusting. If you got a good bench sync, the amount of adjustment needed should be very small.

 

Probably an off-base thought but (based on personal experience) you're sure that the two cables are moving freely,positioned properly and the throttle return spring is springing adequately ?

 

I ran into the same problem after doing the same work to my 750. The problem was caused by one of the butterflies hanging up just a hair. The first time I did the bench sync, I missed it because it was such a little bind that I didn't notice it. The butterfly had just a little, and I mean little, play in between the two screws and the holes on the plate to allow the plate to be mounted to one side a bit. It was just enough to cause the carbs to hang open a hair and it didn't happen every time. Seemed to start as the engine warmed up some. With no load on the engine, that's all it takes for rpms to take off. Take your carbs off and do another bench sync and make sure the close properly. You can loosen the two butterfly screws and move the plate enough to correct. Hope this helps.

 

Symptom indicates air leak.

BUT........

Did you remember to put the air filter back in the box, and close the box lid?

I am one who does not live by the YICS tool. I have one, but to date have never felt/seen the need to actually use it. I don't believe that is the problem. It may help you dial it in for that last 2% on idle performance, but it won't be what is causing the issue...........unless your yics passage is open from forgetting to put one or both of the plugs back in, of course.....

Did you in advertently put the o-ring and washer in upside down on the mixture needles, or forget one or more of the springs?

I would bring the mixture needles back to 2.5 turns for a starting point.

It is also possible to inadvertently swap some of the air jets, as there are a few that have identical sized threads and it is EASY to reverse them. You may need to double check what air jets are where.

Last on my list at the moment......make sure that the gaskets AND the O-rings for the carb-to manifold boots are sealing cleanly and tightly to the intake. It is VERY easy to get leaks there. Also, make sure that you have tightened the clamps evenly and that one or more of them hasn't pulled off of the carb.

Keep at it, you'll get it. Keep us posted, and we'll keep thinking more on it.

Dave F