carb cleaning

[what2do]

Hi there, i've picked up an old qt 50 here in the uk (extremely rare) and am very impressed with myself fo getting it so cheap, because very few people in the uk realise that the engine is the same and that the rear hub has a more desirable gearing in it.

It's an early 80's model but had only done approx. 100 miles before being left for dead in a shed! The carb is like new but when i removed the carb bowl, the liquid which ran from it was very gloopy, obviously 2T oil that had been there for an age, the internals are heavily varnished and i've been soaking it with aerosol carb cleaner for several days but it's no where near clean enough for me. My question is this, would it be ok to media blast it with a very fine peen? The obvious method for cleaning is the ultrasonic choice, however, i don't know anyone local to me that can do it and i do have the facilities to 'b;ast' it myself. I won't be surprised if i'm told that this is a ridiculous idea - i just thought i'd ask.

Over the next few weeks, i plan to undertake most of the machining mods for a pw 50 engine mentioned elsewhere on here but i think it is essential to get this thing running correctly first. thanks in advance for your replies, you will be rewarded with even more questions lol.

[shortyr6]

sounds like you either need a new carb. i would not blast the carb as it is pretty delicate.

also you could try a acid bath.

[bronc3]

It may not look "new", but if the passages and jets are clear and there is no loose material after a serious soak, it should work fine.

[what2do]

New carb definately not required, it is still like new apart from the varnish deposits. I've been advised that blasting with bicarbonate of soda works well so i'll probably give this a go. I'm interested to know what an acid bath is, can i do this myself and what is the cleaning agent?

After several applications of carb cleaner to remove the worst, this morning i tried to remove the pilot jet but can't. it unthreaded easily enough but it won't 'fall' out of the recess that it sits in due to the gunk lining the walls. any ideas on how to get it out, i've repeatedly hit the carb with a piece of timber, nice and gentle but it's not moving!!!

perhaps this is where the acid clean may be of most use to me, please explain what if involves, cheers.

[bronc3]

New carb definately not required, it is still like new apart from the varnish deposits. I've been advised that blasting with bicarbonate of soda works well so i'll probably give this a go. I'm interested to know what an acid bath is, can i do this myself and what is the cleaning agent?

After several applications of carb cleaner to remove the worst, this morning i tried to remove the pilot jet but can't. it unthreaded easily enough but it won't 'fall' out of the recess that it sits in due to the gunk lining the walls. any ideas on how to get it out, i've repeatedly hit the carb with a piece of timber, nice and gentle but it's not moving!!!

perhaps this is where the acid clean may be of most use to me, please explain what if involves, cheers.

You might be able to get some carb cleaner past it while it is loose, and gently wiggle and pull with a pair of needlenose pliers. The cleaner should break the buildup loose.

[what2do]

the aperture which the pilot fits in is (from memory) about 4 mm diameter and it is about 10 mm deep!!!!! no pliers of any sort or tool will reach that far. i guess my last option would be to drill it out but i'm worried about catching the thread on the carb - not worried about sacrificing the cheap pilot jet. any other opinions would be warmly received!!!!

[driedupmotocrosser]

check this out picked it up a few days ago might work for ya

http://www.aircooledtech.com/tools-on-the-cheap/soda_blaster/

[what2do]

thanks for the soda link, saw that earlier on today, got to love those cheap but effective methods!!!! still interested in the acid treatment if anyone has any experience. i don't any form of media blasting is going to help with the removal of the pilot jet, not sure what to do about that just yet. cheers.

[driedupmotocrosser]

try using a small easy out... maybe an icepick might work aswell

[what2do]

Hi again, a little bit of translation from us english to uk english is required here!!!!! what is easy out? cheers.

[driedupmotocrosser]

should be able to get one that small??

[shortyr6]

can you blow it out with the air compressor?

great link to the baking soda blaster. looks like it does the trick.

[what2do]

hi again, i will try using the compressed air method tomorrow but i'm not that optimistic as there is a substantial amount of gunk in the passageway preventing it from coming out and it doesn't help that i can't get 'behind' the pilot to blow air at it to assist it's removal. my last hope will be to use a reverse threaded stud extractor like the one shown above, not sure if i can get one that small though, cheers, mitch.