carb bubble full or 3/4 full after a run, healthy?

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
N

new-fg-owner

Well-Known Member
Messages
260
Reaction score
0
Location
london
hey guys just a quick question its been asked in other threads i just want to make double tripple sure, if the bubble on the carb is full or 3/4 full after a run does that mean its good and healthy? i have a good amount of smoke out the exhaust plus a tiny spit of wet oil hitting the floor while running. when i initially squeeze the trigger the engine sounds a bit brrrrr but that may be because i have a 29cc engine. i have been adjusting the LSN slightly but not the HSN. just some reasurance would be awesom. thaaanks
 
3/4 ..as long theres a small air bubble at top then i think thats a good sign :)

if its running rich (lot of smoke & low speed/bogging when accelerating) lean the LSN a tad dude & see if that helps :)
 
hey tizdaz thanks for your reply dude yaa i mean this morning after a 40min run last night there was a small airbubble at top, but this morning i just ran it in garden for a few mins n bubble left full but ya now i ran the tank totally empty n the bubble is still full lol so dunno if i've tinkered to much. ill load up a video when i next get chance, gettin a bit dark out now though doh.
 
im sure theres something on here about carb bubble,,i think if its full after a run its to rich,,if its half full after a run its spot on,,and empty after a run its to lean,,im sure mike1970 posted it saying that ian oddie told him,i use this as a guide and the plug colour is another way oily black to rich,tan choclate colour just right,and white colour to lean
 
ahh yeh thats the one knew i read it somewhere! ..just got back wit mine from the track ..didnt have chance to empty tank cuz the fker stalled wit about 10% fuel left & wouldnt start back up, think it flooded but dunno ive made a post about it in the engine section :(

other than that though its running great, im happy wit it anyway, those rear arms extended make a difference too, only prob is though my shocks are past there use-by-date, need some upgraded ones or better springs & thicker oil maybe, will see :)
 
hey renbar hmm ya it is a bit odd the bubble still being full there is a small air pocket at the top but thats it. annoyingly i've screwed the spark plug in to tight cos it came lose once n now cant undo it grr. my exhaust is still dripping black oil again now so i'm thinking maybe a bit rich also. indeed guys i've read the two posts there is one by mike, there great posts was just a bit confused because some people say an emtpy bubble means to rich n visa versa so got a bit confused. did you manage to get your sorted tizdaz.
 
wouldnt worry too much about bubble being full after a run as long theres an air bubble in it, this just gives more of a sign that your running too rich.. this could be my prob to i guess as when my engine stalled my primer bulb was full & still is,, gunna try lean it off next run & see if that helps, i fkin hate tuning engines! :(
 
tizdaz said:
wouldnt worry too much about bubble being full after a run as long theres an air bubble in it, this just gives more of a sign that your running too rich.. this could be my prob to i guess as when my engine stalled my primer bulb was full & still is,, gunna try lean it off next run & see if that helps, i fkin hate tuning engines! :(
Click to expand...
oil in pipe is normal, 3/4 primer bubble is fine, i started the last thread on carb bubble being full to the brim because i changed the pop off spring near the metering needle from 25psi nto around 12,which was too low! hense running rich=- full carb bubble.
 
Last edited:
new-fg-owner said:
hey renbar hmm ya it is a bit odd the bubble still being full there is a small air pocket at the top but thats it. annoyingly i've screwed the spark plug in to tight cos it came lose once n now cant undo it grr. my exhaust is still dripping black oil again now so i'm thinking maybe a bit rich also. indeed guys i've read the two posts there is one by mike, there great posts was just a bit confused because some people say an emtpy bubble means to rich n visa versa so got a bit confused. did you manage to get your sorted tizdaz.
Click to expand...

yeah sorry about that i did say i wasnt sure couldn't remember and wasnt looking through 4 million posts to find it,,mines always half full after a run and plugs allways a good healthy colour so i leave it well alone,,plus as soon as i tune the 23 oddie to try to get more i can never start it again ive got no choke to worrie about which don't help,i think though its tuned as good as it can be and ive got as much power a 23cc can giv,,but im looking for more so i thinking of a new one
 
hay again ive just been on youtube watching random videos of people starting up there fg's and the exhaust smoke level is around the same as mine so not too worried about that. kinda wish i hadn't fiddled around with my LSN now it just seemed to be idling slightly fast, runs ok though doesn't bog down, starts second pull (touch wood) lol. ya i hate engines too i'm finding it still the hardest thing to fully learn. gotta wait till next friday now as when i get back from work its dark doh. it be interesting to hear how it goes with your engine tizdaz? hyper how much exhaust smoke you got?
 
hey dwarfy thanks matey ill give him a message gonna get ready to watch topgear in twenty mins woop woop. haha oh no not coke damn bet it goes everywhere full speed lol, soon it'll be doing LSD with green rainbow coloured smoke coming out of it haha
 
POINTS TO REMEMBER
When tuning your engine, after every run make sure you check the bubble on the carb. If this is empty after testing then this means your engine is too hot and running too lean. What you should be looking for is a full bubble or nearly full at least.

TOO MUCH SMOKE
You should also be aware of your engine if it smokes to much, this means it is running too rich and is getting too much fuel. To adjust this turn your L screw in by 5 mins, remember imagine that the screw is the face of a clock, small adjustments is all you need.
 
hey guys thanks for so many replys thanks outaluck thats awesom looks like i've pretty much got it bang on then with the carb bubble. ill keep an eye on the smoke level, ill upload a video soon when i can get one done during daytime. btw is that your boat in the photo outaluck thats amazing?
 
Happy you got it soughted..... and no thats not my boat but will be building a rc drag boat shortly
 
Back
Top