2 stroke engine help ...FIXED

had this sat around for a while but now my son is older hes showing an intrest
can anyone identify the make,theres no markins at all
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i got it as a non runner,so i stripped it all down to the frame and found two problems
1.some of the wiring was dodgy
2.the fuel deliver pipe was nipped and no fuel would go thru
now its running but i have another problem,i have very limited knowlage of 2 stroke,soo it starts ok,bit smokey tho,i mixed the fuel correctly (25:1)
on slight hill it wont pull on full throttle but will on half throttle
initial set off is very juddery too
black oil from the exhaust flange
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can anyone help,thanks

 

tsc is your man for this.

 

25to1 maybe to much oil, the rotax engine is 50to1

the oil leaking from the exhaust may mean the exhaust wadding is full of oil or the mixture is way to rich.

 

thanks ,ok tsc where are you lol
yea it says on the bike 25 to 1 but my neighbour put his han over the fumes and rubbed his fingers and said too much oil in there,so if i dilute the mix to 50 to 1 and thi mix is wrong the engine will seize will it not
the nagging thing is theres no I.D on the bike at all

would too much oil cause the hesitation then

 

looks like one of them cheap chineese imports ?

 

yea i reakon so but i got it for nothing so was very very cheap for me,but to my lad its like having a blade or an r1,just hope i can get it sorted for him

 

ok few more pics number 1 in the pi...is that mixture screw and whick way is weaken
number 2 ,the lever ,this just blocks air going in the carb,i assume it should be open all the time,is that for switching the engine off when theres no electrics
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the engine itself
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the lever (2) is the choke, if fully open it will make it run funny at full throttle .
on mine had to wait for ten mins or so for it to warm up with the choke fully open then close it 3/4 for it to run smooth on full throttle

 

ah right,so when the lever is fully down and the airway is totally open this is "on choke"

 

yeh as far as i can remember ,ive looked for the manual but cant find it

 

see im thinking like carbs on a car,when choke is on the flap is closed,choke off flap open to let air thru

 

to be honest i cant remember witch way . the manual did say . the best thing is to start it up and give it a try , let it warm up for a few mins and give it a go in fully open or part closed , sorry im arguing with my self on witch way so please let me know or i try mine tomorow
cheers

 

ill give it a go,excuse to ride it again

 

well have fun.
hope that is it

 

Choke is in when the airway is restricted, richer mixture for starting.

 

thats what i thort cause when its fully closed it cuts out

 

25:1 is crazy heavy on the oil - I run my chainsaws at 50/1 synthetic (revving to 16k) and my outboard at 100/1 synthetic. I'd try it on 50/1 synthetic first. Sounds like your carb could be gummed up - yank the whole thing and soak it in meths for a while. If you can dismantle it any and have a look, all the better. If you can get to the exhaust manifold connection to the cylinder, pull it off and have a look at the piston and ring(s) for any scoring. Sounds like a carb problem to me, it's flooding at full throttle and dumping loads of oily petrol in. But pull that manifold flange first and take a picture of the piston! And clean the plug...

 

Oh, and check the fuel pipe hasn't collapsed internally where it was nipped - could
be as simple as replacing that.

 

ok thanks tsc,i know the fuel pipe is fine thats the first thing i put right so il do the rest

 

ok update on this,couldnt get the carb off they are cross hea bolts and are locktited in,god knows why,anyhow got the exsors off and tried to take a pic but couldnt get a good one ,however no scoring on the rings and looked very clean in there
re-did the pipes to be 100% sure,blasted carb cleaner in the carb,did a 50:1 mix which looked very week,so put 5ml more in,then it was worse just dying on full revs,so i took the air filter off and it felt better,then i wound the screw 1 ( in pic post 7) out an 1/8 of a turn each time,untill the srew was about 1 and 1/2 turns out and bingo,its pulling fine ,running smoother and idles great
one thing i found is the exzorst bracket was twisted so tight when i took the bolt out it moved the exzorst .5mm to the right and on an angle and allowed me to get another turn on the bolts on the flange,so could have been loosing pressure there,and the engine doesnt shudder half as bad now,so all in all good result,thanks every one for helping out