Carby CNS carb issues- or cat converter?

Sgt. Howard

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Malott, WA
Yes, I did do the thread search on this particular subject to no avail. The carb in question does NOT look like the ones discussed on this board. This is the 'high performance' carb that King Motors sells on their 48cc Grubee Mill. It will start up but not go much past idle- any attempt to demand power gives weak results with engine dieing past one third throttle. Muffler is wet and greasy inside- it is getting fuel. I did re-wire the electrical system to get rid of the cold solder joint of the coil. I am running 18 parts gasloine to 1 part oil for the break in as per instructions.
I just noticed- according to the instructions, this muffler has a catalytic converter on board... I did run this thing initially with a much higher oil content due to a miscalculation on my part. Cat converter on a two stroke? Isn't that like running a full-automatic gas-op machinegun on black powder? Does anybody have experiance with these things?
the Old Sgt.
 
a wet pipe is no indication of the good stuff happening... ;)

a muffler issue will just restrict it at a certain rpm onwards... it will still run.

if it dies completely when you open the throttle wide, not just "restricted", then it is way too lean.

i dont know the carb, but i assume that its a variety with a pilot(idle to 1/4 throttle) AND main jet.

increase main jet. :) learn what a plug chop is :)
 
cat convertors are destroyed by lead... a twostroke in good tune and with the right oil mix is pretty clean exhaust wise. they do need to be tuned up though. if the exhaust gas isnt hot enough, the cat doesnt get to operating temperature.


blow through it :) if you cant, its blocked :)
 
In my opinion, pull the muffler apart (if it's screwed together like the older versions) and pull the cat. out of it.
All the cat. will do is get plugged up with oil over time and give you headaches.
or, get yourself a long pipe (poo-poo) or an expansion chamber. Neither of these have the cats in them.
You can get the long pipe from bgf or luckyearlybird for around $30.00 on e-bay.
I know, lots of people don't like to use either of them to buy parts from, but their prices are cheap and they don't make the stuff....they just sell it.
 
carb/muffler mess

well, I did learn about plug chop, found I was running margionally rich, corrected that. In fact, I tried it on all 5 positions. Tried it with the standard non-cat pipe off my main ride (no improvement), checked the spark plug whilst I was checking the mix, messed with the oil/fuel ratio... as long as I'm running off the idle, I'm fine. It was during the ride home from the shop that I wondered if the main jet isn't plugged. Remember, I just put this thing together- there's any number of things could be wrong. I will look at it again tomorrow and see what's going on there... meanwhile, I'm charging the battery of my camera as it went dead while I was shooting pictures of my operation... want to post these so's everybody can see what's going on.
the Old Sgt.
 
carb & cat issues

took the carb apart and ran a pipe cleaner down the main- I have NO idea what that glop was or how it got there, but now the silly runs like the proverbial primate with the fancy fanny. Put the cat/muffler back onboard and performance actually IMPROVED!!!... I was running the muffler off my older rig. Full power in low and high, a bit muddled in mid but not a big issue- gets better the more I ride it. The 'Panama Jack' is actually a handsome bike with a Grubee motor onboard, almost as if they were built with each other in mind.
BTW- I forgot what mix I ran last Summer when I broke in my 'Flying Horse' motor out of Five Flags in Florida, but the instructions have me running 40-1 after break-in. I've been running that ever since without so much as a hiccough. These new motors call for a higher dosage of oil- what gives? I DOUBT I was running 16-1 when I broke it in and the final mix is remakably oily. Is this normal for Grubbe?
the Old Sgt.
 
theres a lot of whining about oil ratios here...

my opinion...even 50:1 is fine with nice modern oils :)

got to remember these things are chinese. low oil quality. cheap cheap :)

if you realllly are old and arent just preeeetendddding (for reasons unknown :p), youll recall say, a villiers 2 stroke. usually running 16:1 oil ratio.

back then you used plain old motor oil. no real specially developed 2 stroke stuff. they smoke, the smell, the stink!and when im running low on 2 bangers, well... i do the same. :D mix plain oil and petrol just like rum n coke. 5:1 :D

but usually run 40~50:1 with no probs.
 
how old is the Old Sgt.?

well, I'm 57 this month but I've never heard of the Villiers 2 stroke because I've only recently goten into 2-strokes. My big thing is firearms, particularly of the "Reach out and TOUCH somebody" variety. I happen to like long range competition... REAL long range. My first competitive piece was in 45-90. Currently I enjoy the ballistics of 30'06, 308, 8mm Mauser, 7.62x54r and naturally .50BMG
the Old Sgt.
 
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