GS650 carbs - are they corroded beyond repair?

[sacruickshank]

Rescuing the '83 GS650L, currently working on carbs. The needles/slides for carbs 1&4 are stuck, which I'm trying to free up with ultrasonic water & vinegar. The slides for 2&3 are fine since they were spared much of the dirt that invaded 1&4.

Looking closely, years of dirt & water seem to have corroded the carb bodies to the point of damaging/pitting the surfaces (certainly) and perhaps evening locking the slide in place.

If the surfaces are this pitted are these carbs shot? Could they be locking the slides in place? The pic below shows apparent pitting where the slide meets the body.

 

[Guest]

Not exactly encouraging​, but might not be beyond hope.

 

[Nessism]

Photos not good enough to judge.

Try heat to loosen the slide. It looks like varnish, not corrosion, holding the slide in place.

 

[sacruickshank]

Photos not good enough to judge.

Try heat to loosen the slide. It looks like varnish, not corrosion, holding the slide in place.

It's already had some heat, in the form of crock pot with Dawn and then heated ultrasonic with vinegar, but no luck with either.

I've been avoiding super strong chems since the diaphragm is still intact, but I may need to sacrifice it to save the carb itself.

Next step is the heat gun or a brass brush at the joint.

 

[Guest]

Benjamin Moore Paint has a product that is an emulsifier. It is called KP-83 and was developed for the slaughterhouse industry. It turns animal fat into detergent. I experimented with a set of carbs a few years ago and soaked them overnight. It loosened up a lot of the sludgy stuff and I was able to free the slides. I left them in for a few more days and on the third day the aluminum turned a charcoal color. It is a 15% solution in water but it might work faster in the sonic cleaner. They used to sell it in spray bottles for about $7.00 Also experimented with it on removing pine pitch from saw blades. Spray the blade and leave it soak for less than a minute, use a small nylon finger brush on the teeth of the blade and it removes pine pitch instantly. I use it a lot in cleaning kitchens in apartments before painting. Somehow I cant get the spray bottles any more but I usually buy the gallon and mix it with water.

 

[Nessism]

A heat gun on the carb body while prying up with a soft wood or plastic tool should free the slide. Heat both sides of the carb body. I've loosened dozens of slides using heat and gently prying. A propane or butane torch works faster and allows more pinpoint heat, so that's what I use.

 

[sacruickshank]

A heat gun on the carb body while prying up with a soft wood or plastic tool should free the slide. Heat both sides of the carb body. I've loosened dozens of slides using heat and gently prying. A propane or butane torch works faster and allows more pinpoint heat, so that's what I use.

Did exactly that, using a bicycle tire "iron" as the plastic tool and leverage beyond what I would call "gently". No luck yet. Will try again after breakfast.

 

[timebombprod]

id dip the carbs in pinesol for a few hours or so and if you can heat the pinesol up for the carbs, it should help get most of the gunk off possibly making everything easier to come off.

 

[sacruickshank]

id dip the carbs in pinesol for a few hours or so and if you can heat the pinesol up for the carbs, it should help get most of the gunk off possibly making everything easier to come off.

Thanks, i have a garage crock pot for just such things.

But ... the current challenge is not just the corrosion, it's the slides that are stuck. If I can't get them unstuck, the carb bodies will be trashed. Tried ultrasonic, heat gun, and prying yesterday.

Today I'll try propane torch&prying, then maybe morph to PB blaster in the ultrasonic. Still stuck, now onto vinegar in a crock pot.

 

[timebombprod]

best of luck! could put some sort of lubricant if you havent already, im guessing thats one of the first things you did though.

 

[sacruickshank]

For posterity, below is the list of techniques for freeing the slides that have been tried so far with no luck:
1 ultrasonic with water & dawn
2 ultrasonic with witches brew of berryman's b12 carb cleaner, seafoam, and a little simple green
3 ultrasonic with PB blaster
4 Crock pot with water & dawn
5 Crock pot with vinegar, which damaged the diaphragms and discolored the carb bodies
6 Heat gun set to ~700F
7 Propane torch, which melted some of the plastic bits inside
8 Prying with plastic bicycle tire tool
9 Prying with long allen wrench

Success appears unlikely, so trying to source replacements for #1 & 4

 

[sacruickshank]

Photo below provides even more data on just how STUCK the slides are. Time for destructive options which hopefully won't damage the carb body