GX 140 emulsion tube
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GregMartin
I like fast cars
I have one coming from NR racing for my 6.5HP clone. However it isn't here yet. I have an open header pipe and a K&N style filter fitted so the engine will run way too lean without some minor carby mods. I have installed a main jet drilled to 36 thou and the engine runs well and makes plenty of power. The gx140 E tube has less holes in the shaft. It has either 3 or 4 groupes of 3 holes (I think) and from memory the gx 200 E tube has 4 or 5 groupes of 5 hole. I think it also has a different hole diameter in the shaft.
Anyway what all that means is that the engine will run richer with the gx140 E Tube and this should equate to more power at low revs depending on the jet size.
Anyway what all that means is that the engine will run richer with the gx140 E Tube and this should equate to more power at low revs depending on the jet size.
r_chez_08
Should be in the shop...
You can modify your stock e tube with some solder or heatshrink so that you have less holes. The 140 tube is a 3x3 tube. My clone one was a 5x5, and I have seen some 5x6 IIRC.
Doc Sprocket
*********
Great idea! We love the cheap/free performance mods! Thanks!
r_chez_08
Should be in the shop...
No problem, I got the idea from 4 cycle (i spend way to much time stalking that forum!)
GregMartin
I like fast cars
Yep I've seen those modified E tubes on 4 Cycle too. Here's a picture.
Silver solder would work pretty well.
Of course it's only a $7 part or $15 if you want a genuine Honda.
Silver solder would work pretty well.
Of course it's only a $7 part or $15 if you want a genuine Honda.
Doc Sprocket
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I've gotta try that. Why? because I'm a cheap bugger! I've soldered a few jets, so the e-tube oughta be pretty straighforward.
GregMartin
I like fast cars
Yeah Man why not!
Doc Sprocket
*********
Actually, I have the opportunity to try this sooner than later. My kids' kart is running a bit lean since putting the Cherry Bomb on, and removing the governor. Since my son and I will be working on jetting tomorrow, I'm going to give this a go!
GregMartin
I like fast cars
I just (like 10 minutes ago) installed a gx140 E tube in my kids gokart. I can't help but feel it might be limiting the revs, but it could just be in my head. I guess only a road test will tell. It went like a banshee on the weekend with the standard gx200 E tube, a K&N filter, header pipe and a 36thou jet. Plenty of power to spin the wheels on the grass and a top speed of about 40mph.
Doc Sprocket
*********
So- for scientific purposes-
Garry and I were re-jetting tonight. Still a bit lean, but I do not have the next size drill bit. Gonna have to go get one. After we finished playing with the jet and testing, we yanked the emulsion tube. It had 2 rows of 3 holes, and 2 rows of 4. Out of a total of 14 holes, I soldered up 5, leaving 9. I chose that number somewhat randomly, at approximately 1/3 of the total. I soldered because I did not have the right size heatshrink.
The kart definitely got a boost in the low-mid range. Conservatively, I'd say acceleration is up by 5-10%. Difficult to quantify, but was noticeable on the butt dyno. Top end did not appear to suffer at all.
As she's still running a tad lean, I can see how blocking some air holes would not hurt. IMHO, it's better to do the emulsion tube before finalizing jet size. If jetting is perfect, and a richer e-tube is installed, it might require a slightly leaner jet. Maybe.
Garry and I were re-jetting tonight. Still a bit lean, but I do not have the next size drill bit. Gonna have to go get one. After we finished playing with the jet and testing, we yanked the emulsion tube. It had 2 rows of 3 holes, and 2 rows of 4. Out of a total of 14 holes, I soldered up 5, leaving 9. I chose that number somewhat randomly, at approximately 1/3 of the total. I soldered because I did not have the right size heatshrink.
The kart definitely got a boost in the low-mid range. Conservatively, I'd say acceleration is up by 5-10%. Difficult to quantify, but was noticeable on the butt dyno. Top end did not appear to suffer at all.
As she's still running a tad lean, I can see how blocking some air holes would not hurt. IMHO, it's better to do the emulsion tube before finalizing jet size. If jetting is perfect, and a richer e-tube is installed, it might require a slightly leaner jet. Maybe.
r_chez_08
Should be in the shop...
I heard that once you get the right jet, then you should play with the e tube as it is like going between jet sizes.
cumminsbayou4x4
New member
what is a e tube iv never herd of one and where is is it at on my 6.5 clone
r_chez_08
Should be in the shop...
e tube= emulsion tube. Helps mix air and fuel before it enters the venturi.
To find it:
Remove the carb bowl (turn off gas first)
Look up the threaded hole where the carb bowl bolt screws in. There should be the main jet.
Remove the main jet with a flat head screwdriver. The e tube should fall out. If not, tap the carb on a hard surface, or push the top of the e tube down with a screwdriver (it is visible as a little brass tube in the venturi.
You can see it here
To find it:
Remove the carb bowl (turn off gas first)
Look up the threaded hole where the carb bowl bolt screws in. There should be the main jet.
Remove the main jet with a flat head screwdriver. The e tube should fall out. If not, tap the carb on a hard surface, or push the top of the e tube down with a screwdriver (it is visible as a little brass tube in the venturi.
You can see it here
cumminsbayou4x4
New member
do you even need one
Doc Sprocket
*********
Carburetor engineers think so...
cumminsbayou4x4
New member
yeah but it dieals with performance couldnt run with out it
Doc Sprocket
*********
Well- it works like this. The emulsion tube is also the main fuel nozzle, so yes- you NEED it! The fact that it has holes in it to introduce additional air is another thing. That's a fine tuning thing- you could probably get away with no holes at all. Obviously, it will have some sort of effect on performance. I have seen nozzles on other carbs that do not "emulsify", but then- the other carbs are not exactly the same.
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gixxerkart
Big Boss
Can we get a stioch reading on this? A little a/f ratio gauge? Lol. Oh boy, if someone does this we are going too far down the rabbit hole...
r_chez_08
Should be in the shop...
They have afr gauges on a lot of the dyno graphs I have seen for the Hondas and clones. Ridiculous ain't it!
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