Carb Noob

[cowboyup3371]

Honestly, you started the long process to bring this bike back to life. Pictures are encouraged please

[bwringer]

Yep, nothing unusual or insurmountable here.

It's well worth it to do a thorough job now -- you're trying to skip some steps.

You have 32 years of entropy to undo. Take your time, spend a little money when needed, and do it right. It'll be worth it.

[MisterCinders]

Yep, nothing unusual or insurmountable here.

It's well worth it to do a thorough job now -- you're trying to skip some steps.

You have 32 years of entropy to undo. Take your time, spend a little money when needed, and do it right. It'll be worth it.

I don't plan to skip any steps, but if I am missing something, let me know.

With tank, air box and carbs off, the plan is:

1. pull the intake boots and replace o-rings and fasteners;

2. check/adjust valve clearances;

3. clean/rebuild carbs;

4. remove and replace the oil filter cover bolts because they have dodgey threads;

5. obtain the thread expander/helicoil to change the No. 3 plug (which some PO bored out such that new plug won't fit.

Some other possible tasks are:

1. ditch my crappy airbox and go with pods;

2. tighten up the wiring situation -- everything works apart from the gear indicator, but I should replace and restore the insulation around the wiring harness; and

3. change out the jets.

1 and 2 are related, as I understand (barely) that changes to the air system will require changes to the jets.

What am I missing?

[Big T]

1 and 2 are related, as I understand (barely) that changes to the air system will require changes to the jets.

What am I missing?

You're over thinking this part

Changing the valve settings does not require new jets - you tweak the 2 adjustment screws

If you really feel you need new jets, get some from Z1 or jetsrus. Don't use the cheap junk in the K&L kits. Jets are precision devices, poorly made jets just cause you problems

Before you do any changes to the carbs, take them apart, clean them and note the main jet size, pilot jet size and needle position. This will let you know if your carbs have already been rejetted for the header

All the other steps look good. You are now on your way to curing the previous owner syndrome.

[MisterCinders]

Oh boy, this gets better and better.

Got the carbs off and separated.

Pulled the slide assemblies out to find that the slide on No. 2 is dented at the bottom edge. Here are some pics:





Checked Z1 and Bike Bandit, neither has that part. How the hell do I replace that?

Also the pilot screw on No. 1 had no spring.

The adventure continues.

[BassCliff]

Hi,

See if Parts'N'More has what you need.

https://www.partsnmore.com/cat_index.php?model=gs&category=carb

EDIT: Sorry, those are for CV carbs. You might have to check ebay and the Parts Wanted and Parts For Sale sections here in the forum.


Thank you for your indulgence,

BassCliff

[MisterCinders]

Found a set of 4 on ebay for $24. I guess this gives me a few more days to play with valves, clean carbs, and watch others enjoy the beautiful riding weather.

[Big T]

Oh boy, this gets better and better.

Got the carbs off and separated.

Pulled the slide assemblies out to find that the slide on No. 2 is dented at the bottom edge. Here are some pics:





Checked Z1 and Bike Bandit, neither has that part. How the hell do I replace that?

Also the pilot screw on No. 1 had no spring.

The adventure continues.

Now, you beginning to grasp the previous owner syndrome

You just never know what you're going to find!

I wonder how he managed to bend a slide?

Was there any debris/gunk in the carbs?

[MisterCinders]

Actually, there is a mistake in my prior post. That slide is for No. 3.

I have not disassembled Nos. 3 and 4 yet, so I don't know what the bottom of that carb looks like yet.

So far, 1 and 2 look pretty clean inside. No real gunk that I can see.

[MisterCinders]

Other details, FWIW.

Glad I picked up those rebuild kits.

The float seal gaskets are pretty shot. They are so stuck in the bowls, that they have only come out in pieces. Hopefully, I can scrape out the remaining bits after the soak.

Still more questions.

The carb slide show has an ingenious "special tool" using a wire brush bristle to poke into small openings. Fearful of harming more brass, will any wire brush work for this? Should I stick to a certain bristle type?

Any other ideas for good poking tools?

[MisterCinders]

OK, so the float drain plugs on two of the carbs are never coming out. Seriously, the brass screws on them have been stripped to ****. Soaked it in penetrating oil and carb cleaner.

That plug is not budging.

Any ideas on how to get that out?

[Big T]

OK, so the float drain plugs on two of the carbs are never coming out. Seriously, the brass screws on them have been stripped to ****. Soaked it in penetrating oil and carb cleaner.

That plug is not budging.

Any ideas on how to get that out?

Heat them up, the aluminum bowl will expand more than the brass plug

Put them in a 400 oven if you can

The, use a proper size screwdriver or impact bit on the drain plugs

Lots of people poke a wire strand in, I just soak and spray to clean it

[TheCafeKid]

Now, you beginning to grasp the previous owner syndrome

You just never know what you're going to find!

I wonder how he managed to bend a slide?

Was there any debris/gunk in the carbs?

Id bet money that the PO experienced PPO syndrome The VM carb bodies were made of very very soft compound metal, mostly zink and aluminum and some magnesium from what I understand. The BS series were a bit more solid, a bit harder. If those VM carbs were left exposed to precipitation for any length of time, the corrosion of the slides vs the bore of those carbs will lock the slide up tighter than a drum. I made this mistake once.....ONCE. And I tried EVERYTHING in the world to unstick the slide. Prying only did damage (just like the pic) to the slide, and no chemical soaks I tried (Berrymans, CLR, Boiling it in CLR, etc etc) would free that puppy up. Apparently the compound metals in the older carbs and the slides become VERY VERY fond of eachother.

You'll definately want to replace that slide. While the damage done initially would look fairly superficial, the cutaway on those slides are precise and necessary. While I cant say that it would cause a whole lot of problems, at this point, you need to eliminate as many problems or possible problems from your equation as possible.

Which brings me to my next point. Your plan of attack sounds quite sound. I would suggest that you follow the carb cleaning to the letter. And better still, do it twice. Even a little tiny bit of gunk in, say, the choke pickup in the float bowl, or the pilot passages, will cause you grief. The tollerances here are very very small. Besides the soaking in dip, the cleaning with spray etc, some strands of COPPER wire are your best friend here. Copper is softer than the brass in the jets, pick up tube, and passages in the bodies themselves, so it wont do any damage to them such as gouging or the like that could cause problems in the AFR later on. But copper will likely be harder than any crap that might be lodged in the pilot jet, needle jet or emulsion tube etc etc. Use it liberally, push that crap out and then blast the passages and jets with carb spray, making sure each sprays roughly the same pattern. Oh, be sure to wear saftey glasses here. Some of those passages come right back around to your face, and carb spray in the eye is exquisitely painfull. Dont ask how I know..just trust me

While youre waiting on your carbs to soak (and let them soak a day, 24 hours, but no more, as the bodies will start to "skin" with a metallic, sticky residue that could cause your slides to stick... dont ask how I know about that either. And if you can get one, a nylon bottle brush is a nice tool to have on hand to assure your slide bores are nice and clean..) adjust those valves! This is key to assuring you have a proper baseline to start your carb tuning. If you do the carbs first, and then adjust the valves, you'll find you might have to mess with the carbs again.

Lastly, If your airbox is in workable shape (and a good cleaning and a spray with some Duplicolour Low Gloss Black will make her look damn nice again) USE IT FIRST. Its much easier to tune the bike for aftermarket performance parts when it is running well in the first place. Remember, you're setting a baseline for everything here. So having it running in STOCK setup is the best baseline for later changes...


Good luck!

TCK

[KEITH KRAUSE]

Didn't read every post.
If the bowl drain bolts won't come off you can always get some used bowls or live with it for now.
I think your biggest problem may be compression. You mention black/oily plugs. Even if you have good spark and fuel flow, combustion will be poor with low/uneven compression. Leaky valve seals will keep fouling your plugs. Worn rings too. You need to check the compression first and fix it if needed. Any smoke and/or popping at warm up or later?
Carb and electrical service are expected on these older bikes. If your ignition is still points then they need to be checked too for being in good condition and properly gapped. Verify the main jet and pilot jet sizes while you have things apart to be sure the PO didn't make poor changes. Verify jet needle e-clip positions too. I assume the bike is stock and if so the jetting should match the factory installed jetting.

[MisterCinders]

OK - Checked valve clearances. They are all terrible.

My smallest feeler is 0.127mm. None of my valves have clearance to let this pass.

Don't have the tappet tool, but tried to use the zip-tie trick to hold the valves open. http://members.dslextreme.com/users/...ol_zip_tie.pdf

Didn't work.

So I need to get a tappet depressor to figure out what shims are in place. Thought about springing for the full shim set, but I may need more small shims than the set will provide. So I get to wait for the tool to come in and then figure out what shims to order and wait for those to come in.

Also need to replace the gasket for the valve cover and breather cover, as neither survived careful removal to get to the valves.

At least 2 of the main jets are never coming apart, so I guess I am replacing those as well.

Finally, the intake boot on the No.1 carb resists all measures to remove it. Dremeled a slot, but the screw head prefers crumbling to turning. Even a screw extractor refuses to grab anything in this damn bolt.