Time to wake her up...

[jetmechmarty]

There is no separate vacuum shutoff (octy, spider valve, etc) on your G. Only the Specials have them and I believe they are more common than your standard.

[ekim]

Runs but ...

A couple questions.

1. I am also starting to go through the brakes. On an 1980 Std (G) - does the plastic fluid reservoir detach from the front master cylinder? It doesn't separate easily and I don't want to break it. I could more thoroughly clean if it could be removed. Yamaha parts breakdown do not list it as a part number nor is it detached in the picture.

2. Idle and running
I got the bike to run. From cold and full choke it fires right up. Coughs, stutters, misses and no power during increased throttle. Let it warm up a bit and drop to 1/2 choke. Same performance. Warm it up some more idle is a little low and same performance symptoms.
What should I do to proceed with trouble shooting?

Some focused direction from you guys would be wonderful since you have danced this dance already.

TIA

- ekiM

[jetmechmarty]

The reservoir detaches from the master cylinder. It held in place by a packing (o' ring). You will have to match that o'ring at a good hardware store. It does not come apart or go back together easily. You can twist it once the screws are removed. Twist it off and twist it on. You'll need some lube to get it on.

Make sure your coils are receiving full voltage. If you have voltage drops at every connector due to corrosion, it's going to run like crap.

[donebysunday]

+1 on Marty
May I add please, running on choke but not without choke, the idle circuits/jets are not flowing. Have you cleaned the carbs 3 times or more ? (standing joke) Sometimes you get lucky the first time but this is more for the professionals, guys that have cleaned a dozen or more sets. You tend to learn where special care is needed and double check common problem areas.

I need to fix minor leaks in a couple front MC reservoirs, and I've only watched it done once. Should be fun !!!!!

[BA80]

A couple questions.

2. Idle and running
I got the bike to run. From cold and full choke it fires right up. Coughs, stutters, misses and no power during increased throttle. Let it warm up a bit and drop to 1/2 choke. Same performance. Warm it up some more idle is a little low and same performance symptoms.
What should I do to proceed with trouble shooting?

Some focused direction from you guys would be wonderful since you have danced this dance already.

TIA

- ekiM

Your pilot circuits aren't clean enough yet. There is still some blockage in there..

Did you COMPLETELY disassemble the carburetors? The Needle jets (emulsion tubes) will get a lot of crap built up in the wells and cause what your experiencing.

[ekim]

some status

As for the front master cylinder...
I looked at it and give it a slight forceful twist. I can see how it could be coerced apart but I don't want to risk creating another project.
I did several cycles of cleaning with fluid/water/air and got it clean. Yes, the splooge hole is open. I will do some very light polishing on the inside where there is some dirt/roughness/??? - with a dowel and some wet emery cloth.
Seeing the mess I have decided to overhaul the calipers now too and replace the lines with SS. Just get it done and bleed it once.
Any reason not to purchase the techna-fit SS lines?

I went crazy cleaning all the electrical connections (well OK I missed 3 in the left side of the headlight bucket). Got both primary fuses and behind on the fuse block. Checked both the battery ground and the engine ground.
I must say that Deoxit is your friend. After the cleaning I think the bike runs not "stronger" but more "solid" - if that makes sense.

During my prior carb cleaning I removed/disassembled all internal parts in each carb except I did not touch the mixture screws. The rack was left intact and everything soaked, rinsed, air blasted and inspected (clear holes). I did that twice. Floats were removed too and height adjusted.
Today I backed out each idle screw 1/4 turn, then returned it to its original position. In hopes of exercising the seal/position and freeing any trapped crud.

During the electrical contact cleaning I hooked up a lawnmower fuel tank, attached via a tee to my in-line filters. I wanted to random test for improvement during the contact cleaning.

Performance
So after all the above the bike runs slightly better (more 'solid') but still is rough and misses.
A bonus clue (perhaps) is that since I had the external tank installed, the vacuum lines for the petcocks were unattached. When the bike would miss it was observable on the #3 carb petcock vacuum line.
Soooo - my #3 carb is having issues?

I guess I am in for carb clean #2.
It may be a case of some junk loosened and clogged elsewhere or it was just that dirty or operator error or ???

Rather than do the whole thing in the same manner I did prior (which may have been incomplete or incorrect) I need some guidance please.
I followed the youtube video and the carb 101 verbage as best I could.

What should I focus on this cleaning round?

[motoman]

As for the front master cylinder...
I looked at it and give it a slight forceful twist. I can see how it could be coerced apart but I don't want to risk creating another project.
I did several cycles of cleaning with fluid/water/air and got it clean. Yes, the splooge hole is open. I will do some very light polishing on the inside where there is some dirt/roughness/??? - with a dowel and some wet emery cloth.
Seeing the mess I have decided to overhaul the calipers now too and replace the lines with SS. Just get it done and bleed it once.
Any reason not to purchase the techna-fit SS lines?

I went crazy cleaning all the electrical connections (well OK I missed 3 in the left side of the headlight bucket). Got both primary fuses and behind on the fuse block. Checked both the battery ground and the engine ground.
I must say that Deoxit is your friend. After the cleaning I think the bike runs not "stronger" but more "solid" - if that makes sense.

During my prior carb cleaning I removed/disassembled all internal parts in each carb except I did not touch the mixture screws. The rack was left intact and everything soaked, rinsed, air blasted and inspected (clear holes). I did that twice. Floats were removed too and height adjusted.
Today I backed out each idle screw 1/4 turn, then returned it to its original position. In hopes of exercising the seal/position and freeing any trapped crud.

During the electrical contact cleaning I hooked up a lawnmower fuel tank, attached via a tee to my in-line filters. I wanted to random test for improvement during the contact cleaning.

Performance
So after all the above the bike runs slightly better (more 'solid') but still is rough and misses.
A bonus clue (perhaps) is that since I had the external tank installed, the vacuum lines for the petcocks were unattached. When the bike would miss it was observable on the #3 carb petcock vacuum line.
Soooo - my #3 carb is having issues?

I guess I am in for carb clean #2.
It may be a case of some junk loosened and clogged elsewhere or it was just that dirty or operator error or ???

Rather than do the whole thing in the same manner I did prior (which may have been incomplete or incorrect) I need some guidance please.
I followed the youtube video and the carb 101 verbage as best I could.

What should I focus on this cleaning round?

What BA80 stated. Gonna have to remove the emulsion tubes, clean and toothpic all the side holes of them. Pilot jets still likely partially plugged(magnifying glass will tell the story). The sealing teeny-tiny O-rings under the idle-mix screw/washer/spring are likely hard little washer lookin' things and need replaced also.

[TopCatGr58]

Hey ekiM,

This thread I posted a while back has scrolled quite deeply, so you probably haven't seen it, but you might find in enlightening with regards to why the cleaning is so critical!!! http://www.xs11.com/forum/showthread...t=carb+anatomy

Here's the first photo in that thread for a teaser!



Remember, you can click on photos to access the full size if they are larger than 800x600...the default site size it resizes all photos to. Aside from the photos, there's a good discussion regarding the different types of pilot jets and how they are atomized with air!

So....we really recommend REMOVING the pilot screw so you can squirt cleaner more effectively down thru that to better get to those three little ports holes on the inside of the intake portion of the carb throat in front of the butterfly zone as well as the one more posteriorly.

T.C.

[ekim]

Ah Ha moment

TC,

Great link/posting!
Lots of good data for techies like myself (and of course the great pictures).
Things now make more sense.
I recommend that thread become a tech tip/FAQ. Knowing 'why' helps during the process.

Tear down/rebuild round 2 is in process.

[BA80]

One thing I just noticed TC. Not a biggie.

You have the needle jet listed there as the jet needle. The needle and slide aren't shown there. Just sayin'.

[ekim]

almost assembled post cleaning...

Carbs are cleaned and back together except for the idle screws.

Do I need to replace the black o-rings? A hardware store/harbor freight/??? item?

What is the assembly sequence?
O-ring, washer, spring, screw - as put into the carb body

- it is not in any diagram I can find....

[motoman]

Carbs are cleaned and back together except for the idle screws.

Do I need to replace the black o-rings? A hardware store/harbor freight/??? item?

What is the assembly sequence?
O-ring, washer, spring, screw - as put into the carb body

- it is not in any diagram I can find....

Well, if there still black, not broke, and look like an o-ring.....likely be fine.

Idle mix scew in hand......spring/washer/o-ring........approx. 2turns out from lightly seated for initial start-up.

[donebysunday]

Performance
So after all the above the bike runs slightly better (more 'solid') but still is rough and misses.
A bonus clue (perhaps) is that since I had the external tank installed, the vacuum lines for the petcocks were unattached. When the bike would miss it was observable on the #3 carb petcock vacuum line.
Soooo - my #3 carb is having issues?

I guess I am in for carb clean #2.
It may be a case of some junk loosened and clogged elsewhere or it was just that dirty or operator error or ???

Rather than do the whole thing in the same manner I did prior (which may have been incomplete or incorrect) I need some guidance please.
I followed the youtube video and the carb 101 verbage as best I could.

What should I focus on this cleaning round?[/QUOTE]

Flushing the tank is a good idea, I've had a couple that I took off filled with fresh fuel and a whole bottle of Chevron Techron (this is not the weaker Chevron with Techron) put on the shelf for a month. Don't use this fuel in any vehicle, don't ask.

Also check the exhaust for bulges in the muffs, this can mean they are plugged inside with rust. Won't be able to tune if you have this !

[cajun31]

Ekim

It wouldn't hurt a thing if you would grab this off of Ebay. http://www.ebay.com/itm/390954370048...%3AMEBIDX%3AIT. May not need everything listed, however the price is right for everything you are getting. You need to remove those pilot screws and clean the air and fuel passageways within with a good carb cleaner spray and air. You obviously still have some restriction there which is causing your idling sputtering problems. Go back up to TC's response and look at the existing picture as well as the link he posted which shows the carbs sliced in half. He did a good job illustrating those passageways. If they are restricted by debris or pieces of the disintegrated o rings down in there then you will never get the bike running right. A small investment now in new parts and a thorough cleaning will last you years so it is a wise investment. Also before you start the removal process get a small light screw driver, will enhance what you feel, and lightly turn the screws in one at a time until lightly and I mean lightly seated. Count the number of turns for each screw and record that by carb. Once you have cleaned the passageways to your satisfaction reassemble with the new pieces and again seat them lightly then put them back to the number of turns you recorded back out by carb. This will put you spot on to where they were and then you can work from there getting them tuned in.

[ekim]

Sigh

Motoman,
Thanks for the assembly sequence on the o-rings.

All,
So I did another (#2) teardown, clean and reassembly of the carbs.
I removed everything on the carbs. All parts, o-rings gaskets looked fine.
I soaked the rack in the Yamaha water based carb cleaner for a couple hours. I rotated the carb and squirted cleaner in every hole. Several times.
(Prior to that I had squirted some rattle-can carb cleaner into idle screw hole.)
I rinsed the carbs and then air blasted them. All small parts (jets, tube etc) were cleaned and inspected for clear passages. Even used a magnifying glass.
Float levels to spec. Idle screws set "backed out" 2 full turns from being gently seated.

Put her all back together and still kinda rough on choke and stalls on no choke. Missing and backfiring depending on choke setting and throttle positioning. Runs great at higher RPM (4K)

I am at a loss and need guidance.

Could there still be an electrical gremlin somewhere?