professional mechanic stuffed my carbs !

[s head]

I have just read all the threads on carbs on this site and think everything I need is there but still need help with the emulsion tubes.
My bike is a 1980 midnight special that did 37000ks in the first 4 years of its life and has more or less sat for the remaining 23 years with the same fuel in it.5 years ago it was taken out of storage and sent to a well known motorcycle business where a mechanic called trev rebuilt the carbs,installed a new exhaust valve on No1,and changed all the fluids to get her running.He charged the owner $2200 dollars for this.The owner ran it another 120ks and was put in the garage until I bought itat 37120ks.
I got it running sort of and took for a ride and it is impressive above 4000rpm but ran like crap below this fouling the plugs etc.Took the carbs off ,took the bowls off and everything is brown with green fur on it,no suprise after sitting for 5 years,
trev has butchered everything that need s to be removed for cleaning but of most concern are the emulsion tubes.It appears they were seized in place and trev tried to pull them out with some needle nose pliers from the top with the slides removed and has deformed the top part on 2 of them pretty badly which leads me to my first question?
What does this top cut out part on the emulsion tube do and is its shape critical for correct fueling.
Second question is the float heights where set at 18-19 mm which would cause a very high fuel level in the bowls and the mixture screws were all 2 and a quarter turns from seated,would this combination have caused the rich condition and plug fouling?
And finally because I pulled these carbs apart BEFORE joining this forum I ordered 4 K&L rebuild kits! Are they really that bad or should I get something else?
Thankyou for any help on these questions.

[Snow]

When the K&L kits arrive, open the package carefully, take all of the jets out of the kits, carefully place them in a bag, drive out to the river, and chuck the bag into the river. The jets are no good.

[TADracer]

I have a 79 special so I am not sure what differences, if any, there are between that and the 80 special carbs.

To get the emulsion tubes out try tapping from the main jet end with a small brass (or other soft metal) drift. Make sure the main jets are removed since they actually fasten the tubes into the carb bodies. Try to be careful you do not damage the threads for the main jets. The cut away top part is to help create a low pressure area at top of the tube as the air rushes by. Just try to re-form it and it will probably be OK.

18-19MM float heights (measured from the bowl gasket face) sounds like the fuel levels will be really high leading to a rich condition....and possibly dripping of fuel from the carbs when not running. Try 26-27MM

K&L kits are OK but check the pilot jets that may be included. Some of their kits include pilot jets. If they are included, check that they have 6 holes and not 8. The last time I got K&L kits for my 79 specual the pilot jets caused me headaches until I found out about this.

Have fun and good luck.

[skids]

That tab on the top of the tube probably encourages any liquid fuel to spray into the airstream. Not all micunis are like that. You can probably try and polish it so that the main jet needle slides on it better (does it make contact?). I think the 78 and 79s in the US have spring tension to tip the needle towards that tab, so mabye it works as a guide as well. I would try fine grit paper followed by polishing compound.

[underdog57]

A soaking of carb cleaner around the emulsion tubes helped me.
Actually , I stripped my carbs totaly . took the shaft seals out .
So I dunked the carb bodies in a can of non caustic carb cleaner .
For a weekend I let them set on one set ...
Yamaha has a carb cleaner that you can submerge the seals in too...
I would not pound out the emulsion tubes with out some cleaning first .
Bob

[mro]

impressive above 4000rpm but ran like crap below

About 3,000 mains kick in.
Untill carbs clean and floats set won't know if damage to tubes is a problem.

Have removed tubes by removing main jet, then screwing it back in less about a turn and tapping on jet to un-seat tube.

80 carbs stock float height = 23mm
Pilot starting point 1 1/4 or 1 1/2 turns out.

Don't have any experience with K&L rebuild kits.
If current jets clean up....would just re-use em.


mro
BTW, welcome to XSland
promise to not poke fun at ya on yer first post

[prometheus578]

Skids and TADracer are correct.
I do have issue with the K&L controversey. I take an opposing view.
Nothing wrong with the kits.
Yes, there are actually three different syles of pilot jets available that will fit this carb. The problem is, as I see it, was that owners where ordering the wrong style when they ordered them separately from dealerships.
K&L offers all three types. When the parts guy opens the catalog, point to the ones you want. Simple.
Secondly, Yamaha years ago changed the style of pilot jet that they use in the later carbs.
Whether K&L ships the "no holes" jets with their kits... Oh well. These are the same style jets that Yamaha has switched to.
If one wants the original design, order the jets separately.

Here's a long, boring read... "The K&L Controversy"
http://www.xs11.com/forum/showthread...K&pagenumber=1

[tommystinson]

I would have to say that the half circle "lip" on the top of the emulsion tube is critical. It prevents the air flow from hitting the front of the orifice and aids in fuel mixing. I don't think that they are readily available, so an eBay carb set or perhaps motorcyclecarbs.com would be options. Zanotti motor company might have a few in stock as well.
As far as removal goes, I've taken a metric socket head cap screw and threaded that into the emulsion tube and tapped it out that way. If they are really stuck, I would use a transfer punch of a similar diameter, as long as the small point on the transfer punch is small enough to fit fully inside the threaded ID of the jet.

[Erik the Red]

one more way

I initially tried using needle-nosed pliers to pull the tube out. I think Clymers might say to do it that way. Mine were stuck, I bent that lip some, so I just tried to bend it back as best I could. I haven't noticed anything terribly wrong with the carbs that might be a result of that. (Granted, I hadn't ridden her before that, so no point of reference)

To ultimately get the tube out, I ended up using an allen wrench just barely smaller than the inside diameter of the thread hole that the main jet screws into. Light taps and a lot of patience got it out (WD-40 helped). There is a slight hexagon imprint in the brass of the tube, but nothing that'll affect it poorly.

A wooden dowel (as big as barely fits in the hole) would be my method of choice next time. You get the force distributed over the most area that way, and won't risk dinging the brass with harder metals.

[Snow]

They look like this by chance?


Mike's XS has those for Mikuni BS34 CV carbs at $12 a pop:
http://www.mikesxs.net/mikesxs-fuel_...ategory_id=4.4
P/n Part #48-0660

I'm not sure if those are the right ones for your carbs though...I think I read somewhere that there were some from Mike's that worked but I cant seem to locate that now..

[tommystinson]

The Mikes XS jets/emulsion tubes are the same type, but the fuel hole pattern and ID are different. motorcyclecarbs.com has a pretty good chart of all the different subtypes. I would think that it's possible to drill them out, but the tolerance is pretty tight.

[underdog57]

wonder how the taper is on those needle jets(Emulsion)..
I know for a fact 82 and 79 have differant jet needles ....

Bob

[TomB]

I have to agree with Prometheus.

I've used K+L kits and found the quality really good and the fueling on the bike excellent.

I'm cleaning out/rebuilding carbs for a mate at the moment and have found that because the main jet holds the emulsion tube in they are tightened more than normal jets. The consequence is that the jets can break off at the thread when undoing. One of my own jets did this and I put it down to one bad jet, when my mates set of carbs had the same problem I began to wonder. On inspection of the break you could see where the jet had been cracked almost all the way through. As a precaution I've replaced all the main jets.

For cleaning of the carbs I can recommend Ultrasonic cleaning.
Here's some pics

[underdog57]

but if you get a set of needles to match the jets , hmmmm.

bob

[s head]

Thanks for all the advice.
The emulsion tube came out no problem when I stripped the carbs sorry I did not make that clear.They came out really easy with a squirt of carb cleaner from the top but guess they did not come out so easy for the mechanic who stripped the carbs 5 years ago after 20 years of sitting.
pictures are the way to go so I will post a picture of the emulsion tubes.The pilot jets in the K&L kit have the same number of holes but are a different shape?The original mains have deformed slots and are still looking dirty after 2 days soaking in carb cleaner,so would like to use the nice shiney ones in the kit.I live in australia and the kits came from florida so its not easy to exchange them.I will read the K&L thread.The float needles in the kit dont look as good as the ones I took out of the carbs Quality wise so might reuse them.
the carbs are generally in great shape it just Fraser motorcycles ham fisted mechanics seemed to attack everything with a impact driver as all the jets have damaged slots.I restore lots 80s jap bikes 5 on the go at present and am used to butchered parts.I generally leave tuning including carbs,cam timing and gearboxes to the professional professionals but do everything else myself,now I am semi retired I have the time to start to do this work myself and figure the real knowledge
belongs to the owners who love there bikes,so thanks again for your help.
It says in the forum rules YOU MAY NOT POST ATTACHMENTS how do you guys get your pictures posted on the threads?