Carburetor overhaul DIY or not?

[TerryS]

I got pretty good at pulling the carbs out of my 1100 until I realised I was actually chasing an electrical fault... Chances are all you have is a blocked pilot jet or two, but they are very fine and I doubt the Seafoam will get in there to dissolve the crud. My tips would be as follows:

The throttle cable assembly is very easy to remove if you unscrew the two cross-head screws holding the cable bracket on; no need to touch any adjusters on the cables at all. These screws are easier to get to once the carbs are up off the inlet rubbers.

If they haven't been off recently, the carb boots will put up a fight; they're easier to work with when hot and pliable so might be easier to do this after the engine has run for a while.
You can pry the carbs up off the LOOSENED inlet rubbers against the frame cross-member, just be careful not to break off any castings. You need a looong phillips head screwdriver to get to the boot clamps (and a torch). Pay attention to the orientation of the boot clamps and don't rotate them as that can foul the choke mechanism.

New carb boots will make refitting the carbs MUCH easier (especially with some silicone grease added), they were something like $8 each when I bought mine a few years back. You may also find the bowl gaskets have hardened and may tear on disassembly, I bought some aftermarket ones which were fine (and much cheaper than OEM).

The jets are easy to remove and clean, I got very fond of CRC Carb Cleaner after a few applications, may be some addictive substance in there and it has a nice fragrance...seemed to clean jets pretty well too. May have been said elsewhere but don't ream the pilot jets out and make them any bigger; very fine wire, lots of solvent, and gentle probing should get through.

Don't disassemble the carbs more than you need to; especially do not remove the plenum/trumpets, they are a giant PITA to refit. Ask me how I know... I learned a few more Garage Words!

If you have questions or get stuck I found Adam Frymoyer to be super helpful by email. Good luck.

 

[DeanR]

Agree with Terry's advise above.
Pulling the fuel tank (hopefully near empty) is easy, and makes prying off the carbs lots easier.

 

[GGely]

And by the way, when Terry says torch, he means flashlight...

A propane torch Is NOT a required tool for this job...

 

[Smudgemo]

And be sure to use JIS screwdrivers as opposed to phillips or you'll probably be buying new screws. I just bought the D-tool tip from MotionPro as opposed to the Honda adjustment tool that costs $100+.

 

[OkieRider]

Pour a full bottle of techron in a clean tank of 91 octane.

 

[jrp]

It's not that bad. It gets a little tricky if you disassemble the rack, which you shouldn't have to do unless the carbs have really been neglected (e.g. left sitting for 10 years without draining the fuel).

 

[Slydynbye]

That does it. I'm in.
Collective wisdom. All opinions considered.
I think I need to get a carburetor synch tool too.

I have one you can borrow and can assist if you need help. I'm just over here in Fremont.

 

[Smudgemo]

I'm in Berkeley and have a Morgan Carbtune for the sync if needed.

 

[Erdoc48]

Just my experience...3 carb pulls and I never took out the gas tank. Used the handle of a hydraulic jack and a towel to protect the underside of the carbs while levering them off. With mine, the low speed idle jets were clogged (manifest as low rpm at idle no greater than 500, but once on the throttle, it ran fine). Years ago, I used compressed air (needle attachment of air compressor and some carb cleaner) to clean the jets. I didn’t tear down the whole carb bank though. I would say the biggest impediment was getting them back on as it’s tougher to line it all up and pop them back on. New carb boots do help and swapping out the hoses, O rings, and elbows while you’re in there is a good idea. In the past, I’ve had very limited mechanical ability (and still, I’m no master mechanic), but I was able to do this well. I’ve also never synchronized carbs, but last year, I bought a CarbTune and synched the 00 ST. It was a straightforward job as well.

Good hunting...

EDIT: If you’re doing all this, it might be worth taking out the slides and cleaning them as well, plus making sure they’re not torn (rubber diaphragms). As others have said, label carefully (including the body panel hardware) that you’ve taken off

 

[larryg]

We lose either way. My perfectly running 97 ST1100 has been sitting for months. I put Sea Foam in the tank to keep the fuel fresh. And yes, now, it is running rough - won't hold idle with the choke off. I drained the fuel and it runs better, but I'm sure the carbs need a good cleaning. Everything else has been done.

I don't have an 1100, but I do have a 1980 CB900 Custom - which has 4 carbs.
I disassembled and rebuilt my carbs when I got the bike, in 2010.
Since then, I carry a small bottle of Startron with me and put about 1/2 oz in the tank at EVERY fillup, so the gas is always treated for Ethanol.
After 10 years, I've had no more carb issues. The bike starts right up and runs well, even after winter storage. I don't use any other fuel treatment.

My suggestion, before you tear into your engine, is to put a 1/2 can of Seafoam in your tank (and fresh gas), and take the bike out and run it HARD.
You may find that this clears up your problem. It's certainly worth a try.

Seafoam is not a preservative - it's a cleaner. Startron neutralizes the ethanol, which is what screws up your carbs.

Good luck...

 

[red one]

Wasn't it Clint Eastwood that once said a man's gotta know his limitations? I work on my bike and do maybe 75 percent of the maintenance on it but.... things I ain't comfortable with I ain't doing. Luckly I have a good shop that charges reasonable for parts and labor.

 

[Ashley971]

It runs smooth when it's off the idle circuit. When it's on the main, it's fine. The problem I have is that I'm reluctant to ride it without a smooth throttle under 1500 RPM. I need that for slow speed manuevering.

What's a pair system?

 

[Ashley971]

That's multiple recommendations to run it before tearing into it. I'll try it this weekend.

By the way, Sea Foam advertises that their product is also for storage. I used to use Stabil and tried the Sea Foam. Never again.

 

[Ashley971]

The DYI mechanic's dilemma.

1. If I take it to a shop, I'm spending a lot of money on a hobby and I could have done the work myself.
2. If I do it myself, I'll have spent time working on a hobby when I could have done other things around the house.
3. If I take it to a shop, they won't do all of the extra things like replacing aging parts and giving the bike TLC. And if they do, they'll nickle and dime me.
4. If I do it myself, I might make a mistake. It's easier to have a shop do the work.
5. If I have a shop do the work, I'm lazy.
6. If I do it myself, there goes my leisure time.

95% of the time, we can all make a good call as to how to proceed. In this case, however, I have multiple projects going on, with a half disassembled Toyota engine (wife's car) sprawled over my garage.

You guys really helped!

 

[Erdoc48]

I’ll counter the argument this way...when I worked on my bikes, each was apart in the garage for a full week, and I did it piecemeal, a little bit at a time. If I found myself getting frustrated (and it did happen quite a bit), I walked away, did a little more research, and came back. Little by little it came back together, fired up fine, and I was happy. Please note I have NEVER done this type of work on a bike, so it’s a learning curve, but one I have no doubt anyone with a reasonable set of tools could accomplish. I would not let the shop do it, but that’s just me. The only work I have a shop do is use the tire machine to put on my tires (mount the tires).

 

[naedlaen]

Without reading the referenced tutorial, I do not that a lot of people only take one carb apart at a time, or mark the carb and a bag and put all the parts from that carb in that bag. This saves having to figure out which needle goes where if there are different sized needles in the same position (idle or main) in different carb locations.

Neal

 

[dkruitz]

I am working on mine right now, the fuel valve/needle stuck in the seat and are corroded in the 40,000 miles I put on them. Takes about an hour to pull the carbs and fuel tank. Its not very hard. Get yourself a JIS screwdriver so you don't strip screws on the bowls. Carb kit is important to replace the bowl gaskets and fuel valves. All metal bits can be cleaned and rarely need replacing. You can do it yourself well within a day imho.
Do consider changing the coolant bits as folks have mentioned, along with the carb boots to make reassembly easier.
Don't soak carbs or risk damaging diaphragms. Just clean bowls and all that you can get to from there.

 

[Uncle Brian]

@Ashley971
Curious as to which route you took (DIY/shop) and the final outcome!

 

[Mophead]

Pour a full bottle of techron in a clean tank of 91 octane.

Okies and Texans agree. Full bottle of Techron and ride the entire tank. If it doesn't work then you are only out a bottle of Techron. The stuff does wonders.

 

[Aladinbama]

The DYI mechanic's dilemma.

It's July now - what did you do?

With that asked, I'm about to dive into mine. I have a rebuild kit ordered and will determine whether or not it has diaphragm issues when I get in them (but it most likely does)!