Got myself a pocket rocket :D :D Now what? Fuel ratio?

[Joshmcmillan]

Hello,
In the next couple of hours I'll be going to pick up my pocket rocket. (pictures below). Not exactly sure what engine is in it at the moment, but I assume a 49cc 2 stroke. It was $215 and comes with a new chain, sprocket and stand.

The guy said to use a 20:1 fuel ratio, but I thought that most were 40:1 or 50:1. What's your opinion? Do they vary?

Not that I want to do anything yet, but eventually I'll probably be looking to mod it a bit. Is there any free mods that you can do to 2 stroke engines? What are some of the most common and effective mods?

I'll make a video later this afternoon most likely, and I'll post it here

 

[Russ2251]

The guy said to use a 20:1 fuel ratio, but I thought that most were 40:1 or 50:1. What's your opinion? Do they vary?

Very generally, the hotter a 2 cycle runs, the more oil it needs.
My ratios (between several makes and models) run anywhere from 11 to 100:1. Better to run safe. 20:1 will never hurt.
Run less than recommended and end up with a lump of aluminum.
Run the 20:1 until manufacturer tells you otherwise.

 

[robin]

a proper exhaust is a good mod for a 2 stroke

 

[Joshmcmillan]

a proper exhaust is a good mod for a 2 stroke

How expensive are they? Noticeable power increase?

 

[robin]

i could not tell you i have never bought one for a mini moto i think ebay is your best bet


if you change your fuel oil ratio you will have to change your jets say if you went from a 50 to 1 mix to a 20 to 1 mix the engine will run lean and will over heat in wort cases eat pistons

 

[Kenny_McCormic]

i could not tell you i have never bought one for a mini moto i think ebay is your best bet


if you change your fuel oil ratio you will have to change your jets say if you went from a 50 to 1 mix to a 20 to 1 mix the engine will run lean and will over heat in wort cases eat pistons

Is english your primary language?

 

[jr dragster T]

Lol his grammer isnt that bad.

 

[Russ2251]

if you change your fuel oil ratio you will have to change your jets say if you went from a 50 to 1 mix to a 20 to 1 mix the engine will run lean and will over heat in wort cases eat pistons

I've heard this rumor before. Please articulate w/sources.

 

[jr dragster T]

I heard that jetting VS oil thing isnt true, heard on dirtrider.com
Like jetting is the ammount of fuel and oil the engine gets. If you whent from 20:1 to a thinner ratio then I'd see some overheating issues but going fatter on the oil? I dont think so IMO.

 

[Kenny_McCormic]

Something about a thicker liquid needing a bigger hole. But it could just be as people are enlightened to the benefit of NOT starving their engine of oil they also realize that they are running far too lean.

 

[jr dragster T]

I think aslong as your blowing some good smoke at you watch your CHT's and EGT's you'd be fine.

 

[Russ2251]

Clinton 2 cycle manual clearly states that during break in, a mix of 20:1 is necessary for first 2 gallons.
After break in, mix is to be 32:1 for entire life of engine.
Also, when heavier mix is used, exhaust smoke is equally heavier.
When engines with heavier mix are disassembled, more oil (not less) is found in bottom of crankcase.
The jetting/oil mix argument is clearly flawed.

 

[jr dragster T]

So Russ is it normall to have a small puddle of oil in the bottom of the crankcase?

 

[Russ2251]

So Russ is it normall to have a small puddle of oil in the bottom of the crankcase?

If not a puddle, then at least some dripping from critical parts such as connecting rod and/or crank throws. If it weren't there, I'd be more than little concerned.

 

[jr dragster T]

Ok thanks I guess the 2 strokes that I have are doing good.

 

[Joshmcmillan]

I got it Bought myself a 1L bottle of castrol 2 stroke motobike oil and a tin to mix it in too. I put the new sprocket and chain on it (as he broke old chain and bought a new one that has different teeth). I put it on, and tried to start it without throttle, I think I flooded it (3-4 pools like that). Because it just starts and stops now. I'll wait 20 minutes and try again.

BTW does it hurt to spin the wheel therefor spin the engine shaft while it's turned off?

I hope it's just flooded :O

 

[Joshmcmillan]

Hello,
I got it going, it goes about 2km/h, struggles to start moving, and it puffs a lot of smoke and drips fuel out the exhaust.

It's got the fuel he put in it, so it should be the right ratio (20:1).

The man I got it from would weigh as much as me, he used to race it, whats wrong

 

[BradenM]

These engines normally use 25:1. I use 15:1/10:1 and have never had to re jet the stock carbi. 20:1 is a safe bet. My understanding is that these engines are more susceptible to breakage then this one which we use for Energy Breakthrough. You are very lucky, because your motor has lots and lots of upgrades available including exhausts, flywheels (the stock one is performance robbing) carbi's, e.t.c. Very nice buy!

 

[BradenM]

Whats it revving like? Sound normal? The clutch on these things are ****, we run direct drive. It could be a maladjusted carb, poor mixture, clogged jets, clogged intake, or an exhaust problem. It could also be running far too rich. Run over these things and try again.

EDIT: By process of elimination I would replace the fuel and mix your own.

 

[Joshmcmillan]

OK, I took all the junk plastics off the front and bottom, so it's a lot better to steer now. I took the spark plug out and it looks good. I adjusted the throttle a by around 2 turns, and It made it go about 10km/h, so I turned it right down the bottom and it didn't start. Where abouts should I have the throttle. btw I'm adjusting kind of a long nut, that's it right?