No acceleration when turning throttle, stalling, problems

I was doing some maintenance on Saturday (oil change, fix idle screw setting). So i did my oil change, also had a look at my air box because ive had a rich mix problem that i cant fix at the carb (the mix screw has no head on it, and im too poor to be able to afford a new carb). So i thought id whack a couple of holes in the air filter, tape them up, then open one at a time and test the acceleration. So all is going well as im doing this, and i get it set to a point where the exhaust gas no longer stinks of petrol (just a faint whiff), acceleration is better than it was, i turned the idle screw about 3 full turns down to get it back to point where the trans wasnt engaging.

So i gave it a few revs to just check it was still fine and disaster strikes. It is hard to start the engine now, and when i do get it running im getting white/grey smoke that stinks of petrol and is oily to the touch, out the back. Twisting the throttle does nothing, no acceleration, but it occasionally sounds like its bogging or misfiring. Applying no throttle generally results in a quick stall. At the same time the starter motor failed (just to annoy me some more), but a friend is sending me one, so that should be fixed on wednesday.

Has anyone got any ideas on what it could be. Im guessing this is beyond carb level (the venturi was closed when checked and not jammed wide open, and i couldnt see anything else that was obvious), and probably an engine problem. I tried searching google using the faults as search terms, and a couple of things came up, ranging from head gasket to blown rings. Obviously if the problem is a terminal one, id prefer to find out before i spend any money.

For information purposes the bike has done about 34,000 miles, and is a Honda Dylan 125.

Thanks for any insights you can give.

 

it could be your piston rings , what they do is when the engine is going through the cycles oil gets onto the bore to lubricate it and the rings wipe it off again to stop it burning oil n usually when there knackerd you got white smoke that smells distinctly of oil but as for the bogging that could be a air leak from the holes you drilled

 

Going to try and get it started prior to installing the starter motor, then take it from there. If the power issue disappears and i can ride it, even if it has no acceleration, i could live with it.

Hopefully not the rings as that would spell the end of this bike for me, and signal the need to find a replacement asap. I can do most things on this bike, but i haven't gone into the engine as of yet. Plus a new piston set is about £150.

 

I decided to do things by the numbers, per se.

Ok number one, rule out problems caused by sheer stupidity. And this is where i found myself. On saturday while i cleaned the air filter i stuffed some toilet roll in the hole to keep the wasps/flies out. When i removed it, i didnt get it all. So today i have to take the air box off to get at the starter motor, and stuffed into the carb is a whisp of toilet roll. and

Now in my Haynes manual it rates a starter motor change as 3 spanners, ie mid level. Now i have to say it is in no way a 3 spanner task, 2 spanners maybe. You remove the airbox (4 bolts and a screw), remove a further 2 bolts for the starter motor, a nut to get the power lead off, then jostle it a little to get it to slide out. Place the new one in and do everything in reverse. Job done in about 40 mins, less time than the damn carb took, plus id never done a starter motor before. But their is still a problem with maybe the switch, as you have to wiggle it a bit to get it to start.

Anyways i left 3 of the holes i put in the side of the air filter plastic closed with elecrical tape, and 1 open. Reassembled everything, replaced the battery and decided to turn it over, and guess what, it started up. Had to readjust idle screw again, but it works. No idea what the power/accel is like, but the exhaust fumes are less rich in petrol, and much nearer to your average car. So hopefully that means ive sorted out the lack of air problem (for now).

I will take it out in a bit to test it, but it seems to be running ok from what little i tested.

So sorry for wasting anyones time. I am an idiot, but then i guess you have to make mistakes to learn from them.

Thanks for everyones help.