Ultrasonic cleaning carbs

[Guest]

Hey guys really new here. Just bought a 1980 GS550E and working on cleaning the carbs and fuel tank.

I have access to a very big ultrasonic cleaner and my question is what all do i need to remove from the carbs to be able to clean it in the ultrasonic tank? Also would cleaning the fuel tank in the tank be worth it as well?

[Steve]

What to remove from the carbs?

EVERYTHING.

I don't have an ultrasonic cleaner (yet), but can't imagine how the sonic energy would get into all the little nooks and crannies that are necessary for a proper cleaning, unless you strip everything off the carb that might be blocking the end of one of the passages. That pretty much means that you have to strip them down just as far as you would if you were chemically dipping them.

When you put them back together, DON'T use "carb rebuild kits". The parts are usually of questionable quality, and there are not enough parts to do the complete job. All you really need is an o-ring kit from cycleorings.com. The guy that runs that place is a member here and provides a wonderful service to members here. Be sure to also get the o-rings for the intake tubes, as well as the stainless bolts that hold the tubes. All together, you will spend less for all that than you would for a single "rebuild kit".

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[gsrick]

Hey guys really new here. Just bought a 1980 GS550E and working on cleaning the carbs and fuel tank.

I have access to a very big ultrasonic cleaner and my question is what all do i need to remove from the carbs to be able to clean it in the ultrasonic tank? Also would cleaning the fuel tank in the tank be worth it as well?

I don't know how big a very big UC would be, but mine is a 30 liter tank. I can put multiple carb racks in it and if it is at least that big, remove everything possible, but you don't need to separate the rack or gang of carbs or to remove the butterfly plates. Some of the choke plungers can be hard to get out when the rack is left together, so when I can't get them out, I'll leave the bar that ties them together on the rack and wire them in the open position, so the choke passages also get cleaned and I also stick something in one of the carbs to hold the butterflies in the WOT position.

The cleaner I use in my UC tank doesn't hurt rubber like carb dip does, so you don't need to worry about the choke plunger oring or the oring for the fuel connecting tubes. These are in the oring kits Steve mentioned, but if there was no previous leaking from them then I don't think it will from being in the UC.

As far as putting a fuel tank in the UC, mines not that big, but I don't see why you would want to do that anyway.

[Nessism]

With old carbs like those on our GS's it's important to change the fuel transfer tube O-rings and the only way to do that is to ungang the carbs. These O-rings get exposure to ozone and that turns the O-rings hard and brittle. It's typical for them to literally crumble when you try to remove them from the transfer tubes.

[standswithabeer]

i had serviced the carbs on my 79 GS550E project, and after a little bit of deliberation decided to replace the o-rings on the fuel transfer tee and straight connectors. turns out i don't have o-rings there. it appears the tee and straight connectors were replaced with ones that have little ribs where the o-rings would be, but are rubber (or otherwise) coated for sealing. not sure why that's the case, but wouldn't be too surprised if i had probs there. if so, think i'll source connectors w/o-rings. anyone else seen this?

[Nessism]

i had serviced the carbs on my 79 GS550E project, and after a little bit of deliberation decided to replace the o-rings on the fuel transfer tee and straight connectors. turns out i don't have o-rings there. it appears the tee and straight connectors were replaced with ones that have little ribs where the o-rings would be, but are rubber (or otherwise) coated for sealing. not sure why that's the case, but wouldn't be too surprised if i had probs there. if so, think i'll source connectors w/o-rings. anyone else seen this?

Some versions of GS/Mikuni's were this way. The rubber dries out, cracks, and shrinks. There are some aftermarket parts available that take real O-rings, or you can make one with a small lathe if you are handy.

[Mr.humbucker]

I have an ultrasonic cleaner and have done about a dozen sets over the last few years. I agree with Steve's direction here but would add not to attempt to remove the butterfly/throttle plates or whatever they're called. They're a pain to remove and reinstall. You can clean them and the mechanism by putting them in the ultrasonic cleaner. For sure replace the o rings with using those sold by Cycle O Rings and the little rubber plugs as well. Be sure to disassemble the choke mechanism before the cleaning. Spend the time, follow the instructions found in the reference sections on this site. YouTube has a couple of great videos too.

A 3/16th slotted screw driver will be the ticket to remove the jets for cleaning. I if they don't come out first time I try I spray some liquid wrench in and wait a bit. Heat will sometimes help too if they're stubborn. The key to successful removal is the 3/16th screw driver, $5 at HF.
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[THartsock02]

Thanks for all the advice. I have the carbs mostly taken apart but still ganged. Gonna take the bath this week

[UKAndy]

I have owned my own ultrasonic cleaner for a few years, I use it for carb and brake rebuilds many. My experience is that you have to remove all jets, chokes etc. Whilst I will always use an ultrasonic cleaner please be aware they will not always clean badly blocked jets or passages. I have not experienced this with VM carbs but I recently helped restore an RD400 and its air jet and needle jets were blocked with dirt and after the first clean in the ultrasonic cleaner I head to manually clean the air jet and needle jet with a jet cleaning needle. My advice is to remove and much as possible. Don’t put any rubber parts in an ultrasonic cleaner. You need to add a carb cleaning solution and heat the bath to 60-70C to get the best results. I cleaned my GS750 carbs and during cleaning one of my starter jets fell out due to the vibrations so check carefully before you empty your tank in case anything has become dislodged.