Removing ethanol gum

[beezermacc]

Hi Folks! I'm in the process of getting a bike going which hasn't run for about five years. The bike is the A10 with the Rotax engine in my avatar so I'm not sure if this question should be posted on an A10 forum. At the risk of being chucked off I'll pose it anyway and perhaps this question has been posed before...... The carb is full of gum, presumably from stale ethanol. I cleaned it out by dismantling and using all sorts of products like carb cleaner and white spirit but nothing seems to dissolve the gum properly. I thought I'd done a good enough job but on refitting the carb there is still obviously a problem with the slow running. I've just dumped about a quarter of a bottle of Redex injection cleaner in the tank, hoping that might help and have also purchased an 6.5L ultrasonic bath with enough cleanser to make about 40L of cleansing solution so I'm going to get there in the end! But just wondering whether anybody out there knows the identity of a 'magic' fluid which might do the trick? I've seen the thread about Seafoam but I think my problem is different. I'm not looking for a fuel stabiliser or fuel additive but something to actually clean the carb out once the damage has been done. Obviously I need something available in the UK.

[unclerob]

Hi, came across the same problem on a Pan European a couple of months ago....looked like the owner had been trying to run it on araldite!! In the end I found the only way to get it really clean was a soak in a bath of acetone. If you try it be careful to keep it well away from any rubber bits though, I obviously wasn't and found once I'd put it all back together that I'd neatly bonded all 4 float needles to their seats!!

[Butch (cb)]

Had the issue with a Ducati - sent them off somewhere and they came back clean ... for a price. Acetone trick sounds plausible though.

[beezermacc]

useful info. Thanks. The ultrasonic bath has arrived today. The instructions are absolutely useless, hence my next post!

[markyboy64]

Dump the ultrasonic bath. Or let your wife clean her jewellery with it.  You need something that works.

Go to a paint store that knows their trade and get a litre of Methyl Ethyl Ketone. It is a solvent.
(not Methyl Ethyl Ketone Peroxide...) that is the catalyst used in fibreglassing.
Beware, use acid resistant gloves when using this stuff.
Whilst not an acid, it will strip all the oils out of your hand and has been linked to causing cancer . (But then, so is gasoline).
Just treat it carefully.

I have just had a set of Keihin carbs ultrasonic cleaned for a Honda I am restoring and all the "shellac" remained in the float bowls.
I tried Turpentine, Acetone and whatever other solvents I had , but when I used the MEK, Wow.
All I had to do was swish it around the bowl for 30 seconds, discard that and rinse again with the MEK and it was brand new !!!

I would hazard a guess that it would be less than sympathetic on neoprene o-rings and such but have not tested it.
This is not third hand information... It really works !

[RichardL]

Having been in the loudspeaker manufacturing business in the '60s and '70s, MEK was everywhere, since it was the basic solvent used in most of the adhesives. Vapors abounded and, at the end of the day when your hands were covered in glue, washing with MEK was the best way to get clean. I'm not saying it's safe. Nothing so volitile is (MEK has the fastest evaporation rate of any solvent I know of) but, so far, the only apparent illeffect is a tendency to write in a longwinded fashion on seemingly inane topics and with little expertise.

Richard L.

P.S. I always keep a can of MEK in the garage.

[worntorn]

I have the same problem but have given up on cleaning in favour of replacing the Carb with a clean spare.
The crud in the dirty Carb looks more like the material found on old battery terminals, white and very crusty, tough to remove.
MEK is effective solvent but also  considered dangerous to health, like most products that work well it seems.

Glen

[jachenbach]

Soaking in lacquer thinner has been working for me with clogged fuel injectors.

[Butch (cb)]

MEK is effective solvent but also  considered dangerous to health, like most products that work well it seems.

If it doesn't have an outline of leafless trees and upturned fish with crosses for eyes on the label on the back it's probably no good and best avoided.