New Muffler, muffled power

[Echotraveler]

im gonna re-read that last post again in the morning..right now im a bit sad, because i dont understand that much, but i gurantee ill learn!....
went out with the GF on her new bike and i was following...it wasn't very good i could get into speed but with that strange 4 stroke sound nothing like a weed wacker... found a pretty steep slope and tried to go up...the bike was vibrating and on the verge of shuting down....

some days before (with the open exhaust) i could do zip fast up that same slope! as i said ill re-read but for now i sleep...see ya Norman
just did a gallon with 4oz of oil..did

also i can feel something is loose inside! i need to open the motor to check....the motor never did this before......

 

[Echotraveler]

ok so heres my game plan

im gonna do 2 things today:

1. gut the muffler
2. put the spark to .025

then seee whats up....the mechanical sound worries me the most...its not normal! could something come loose when going backward on the bike? cause i know ones i was putting the chain on the small motor sproket moving the sproket backwards, and something came loose, got it tight back again, but maybe by moving the bike backwards i got it loose again...is this possible?

 

[Norman]

something loose? Have you made sure that the big nut on the front sprocket is tight and the nuts and the big slotted screw on the engine crank is tight? You can put a rag in the teeth of the two gears to lock then up so you can tighten up all of those gears nuts. That sounded naughty but it was not meant to be that way.
there is 3 screws under the clutch that could be loose but I kind of doubt it. One thing that will make some terrible noise is the short rod and ball under the front sprocket cover its the parts that work the clutch. If they are not keep greased they will cry sounds really nasty when they need some grease.
see if it has a cat inside the device that converts unburned fuel into non toxic particles You might just want to remove that if you can I have not had one of those mufflers so I'm shooting in the dark .
You are going to be using a light go to 0.020 spark plug gap it will like that more and work just fine.
I hope you get your bike to running good.
Norman

 

[Bikeguy Joe]

Sorry to step on your toes Norman, forgot this is your special forum, just trying to help with an issue you seemed to have missed.

Good luck echotraveler.

 

[Echotraveler]

another update

well i went home an rode the bike back to work after eating!

starting: when cold iddle is not very good, but one the engine is hot the iddle is pretty normal.

acceleration: had to take a pretty steep slope and it didnt stall, but had to put the thorttle to max....the 4 cycle sound is still there, when going from low to high rpm it stalls a bit but gets going ok. had to push the throttle to the max the whole time to get here. max mph 20, asked a motorcycle that was by my side. ( i guess 20 is ok for break in, but not on max throttle....

the mechanical sound: when i got home, released the clutch tension and opened the small sproket cover. the nut inside the small sproket was very loose....so i tightend it as hard as i could.....im not sure it fixed it because i cant really hear much inside the helmet..lol

im waiting right now for the engine to cool a bit to check if the spark plug cleared a bit.


what do you think Norman?

ps the needle is in the second slot top to buttom

10 minutes later update: GOOD NEWS! the spark plug is brown!

oh another thing i may point out: my throttel cable still has a lot of adjustment to it, i mean i can accelerate more by twisting the little nuts that adjust the cable tension.....

sorry for editing so much lol but im "ocd" with this....could it be that i think my intake is sealed when its not?

 

[Norman]

need to see the spark plug did it run better on your new mix?
I'm thinking your main jet is too big or out of round hole if the spark plug is still black I would sure find out what size the main jet hole is.
Have you measured you needles diameter? The taper by chance could be too much( makes it rich) but most are way too fat(not enough taper makes it lean)
The nut you tightened was it the front sprocket nut? You can tighten it easier if you remove the clutch cover and as your tightening the front sprocket nut jam a rag into the gears on the clutch side it will lock the gears up and allow you to put the needed torque on the nut or any of the nuts on the clutch and gear train of the engine.
Most of the below can happen in extreme conditions like the seizing, burn holes in the piston if left untreated or neglected
rich will make it 4-stroke, fowl spark plugs, smoke to beat the ban and use too much fuel it can also make the exhaust drip unburned fuel.
Mark its spot like a Harley. Mine all mark their spots even with the proper fuel/air mix so don't get too excited if your bike drops a couple of oil drips on the floor now a puddle would get my attention. I would then make the MB's stay away from my Hog, I don't want them teaching it bad habits.
Norman

 

[Echotraveler]

ive edited my message so much...

yes, the spark cleared right up, its brown! yeS!
im going to write down teh measurements you gave me for the needle and the jet, im going to a machine shop today.

what do you mean by the "taper"?

tightened the nut on the sproket that holds the chain the one covered with a lever on top..it was pretty loose so i just tightened it up the best i could, noticed a little ball of black stuff, like a little ball of burnt rubber or something

also opened up the right side of the motor, theres a black small nut with a screw holding it in place, i can see its not screwed all the way to the end.

what else, havn't noticed dripps, but ill be sure to park the bike away from the carpet!

so its too rich....
now that the mix changed, and the plug is brown..should i try to lean it out by putting the c clip on the uppermost part of the needle?

after we finish this disussion you should rename to thread so other Newbees can search for it and read...i just re-read the other thread "muffler fell" and the info is very good! its like a class.

 

[Echotraveler]

hey Norman heres a pic of my spark plug..check it out

 

[Echotraveler]

this morning i put the needle on the upper slot (1st slot of the fat end) and took a ride, the bike started very well
iddle was ok
acceleration was sort of dull, but im thiking 20 mph our in my 100pound bike is very good.
Noticed a prominent stacatoo sound on the uphill part of my commute,


so right now the plug is brown
the intake is sealed
now getting the cat out or opening a bit more the muffler. do you think its ok to ride as i am?

 

[Norman]

Your plug is still rich more black than brown look at the center porcelain that is where you need to look I have a picture and some of the needle. You might get a better idea of what they should look like.

picture of my plug its been idling but you can see the center is Grey and dry. The grey probably due to the oil in my mixture using Castor and a syn. oil other wise it would be a more tan or brown could be its a little lean but it runs cool (350 degree's on the head) good power all the way from idle to wide open.

top needle measured about 0.078 this in the idling circuit part of the needle

this is at the tip of the needle around 0.067 to 0.068. controls 3/4 throttle . Wide open will be controlled by the main jet I think mine is 0.026or 0.027"

does this help?
Norman

 

[Echotraveler]

i can understand now the difference in width, but how can the top of the needl control anything? i mean how does the thicker top control the iddle?

i thought the needle went down to the little arm that holds the float in the carby. and by placing the clip up or down you control the preassure on the float. so the needle doestn really control the air, it controls how much gas the carb will mix with air...obviously more gas means less air, and less gas means more air to some extent.

now im a bit lost on how can the thicknes of the needle affect both iddle and accel.

 

[Norman]

Oh boy! the air is controlled by the throttle slide slide and engine speed open throttle the slide goes up so more air can enter. makes since to you?
the slides needle is in a seat the long tube made of brass at the end of that tube at the bottom is the main jet. with the throttle closed the slides needle is all the way into the seat of the long brass tube or emulsion tube so very little fuel can come up into the carbs throat/ venturi and the air is blocked off by the slide being shut. fuel does get by the needle as it slightly smaller in out side dia than the long tubes insides dia. As you open the throttle the slight taper of the slides needle allows more fuel and the slide allows more air and it allows the engine to speed up.
in simple terms.
The float is there to keep the carbs float bowl at a constant level as fuel goes out of the float bowl through the main jet up inside of the long brass tube which has the tapered needle sort of allowing a measured amount to come out into the venturi of the carb all of this is due to low pressure inside of the carb due to the pistons movement.
Back to the float as soon as the fuel level lowers just a little bit the float opens the needle that when at rest it is holding closed (float needle the very short pointed thing inside of the thing that the fuel line is connected to on the carb) its supposed to keep a constant fuel supply in the float bowl. there is a long taper needle attached to the throttle slide and a short fat needle in the float chamber so 2 needles so to speak inside the carb that do 2 different things check out my carb tear down and you will see it all taken apart. Then it might make more since to you.http://motorbicycling.com/f39/motorized-bicycle-carburetor-install-rebuild-302.html did I confuse you? Just be glad when it all works right. There is lots of things going on what we take for granted and never see. Glad your interested that is good.
Norman

 

[Echotraveler]

hello Norman,

yesterday after work i went to visit a friends machine shop

ill take a pic...the mufflers straight tube (the one blowing smoke out) was changed for bigger diameter tube. now it sounds quite but not so restricted.

Cheers,

ill continues tuning it as yesterday after work i went out of gas...and had to refill with my eyeball mix lol

(this last message was written on friday before i left for the weekend)

 

[Norman]

Can't you use the oil bottle for a measurement device? Most oil bottles are marked in ozs. The wallword 8 oz bottle would work or go to the store and get a baby bottle mark in cc's and ozs. use that to measure the oil then get your self a gas can and mark it for 1 gallon. that way your on the money for the mix. If you use a 2 gallon can 8oz of oil will mix up 2 gallons of fuel at 32 to1.
You might google how a motorcycle carb works I haven't but you might get lucky
Norman

 

[NEAT TIMES]

Norm, This Is My New Avatar By The Great Artist "hiker". I Would Like Him To Put One Of Your Head Lites On It. Ron

 

[Norman]

COOL bike ol Hiker is on the ball with the avatars.
Norman I like this one

 

[ibcnya]

I use a liquid codeine bottle for measuring out my mix. Marked in ounces.... Go .022 on the plug gap for best top end results. Get a #65 jet and set your needle at a point where the engine doesnt bog when going from idle to WOT.

 

[Norman]

there has got to be 100 ways to tune one of these maybe? thanks for your input.
I like 0.018 to 0.020 for the gap and if I have to I'll go to 0.017. Your measuring bottle is a good idea but I'd remove the codeine label if you haven't don't need the police stopping you and trying to bust you if you carry it on your bike.
Norman

 

[ibcnya]

there has got to be 100 ways to tune one of these maybe? thanks for your input.
I like 0.018 to 0.020 for the gap and if I have to I'll go to 0.017. Your measuring bottle is a good idea but I'd remove the codeine label if you haven't don't need the police stopping you and trying to bust you if you carry it on your bike.
Norman

Already done, the label came off before I ever used it. Its able to measure out up to 4oz of oil and the cap prevents it from leaking out. This way when I go to fill up the gallon jug I carry in my storage compartment its pre measured and all I have to do is pour, shake, mix and fill. I have a moped BTW that I removed all the oil injection system off of and chose to run premixed fuel.. Tomos peds have issues with the oil injection systems failing and destroying engines.

 

[Echotraveler]

hey guys thanx for all the advice! right now the motor is working ok.

the muffler (as you can see on pics above, on my other post) has a bigger end pipe now....the original one fits right inside this one.

so it rides on the top of the needle, it gos from bike to motorized pretty smoothly, with a bit of that sound the tranny in car make when going backward, the same sound it does when your goin uphill slowly and engage the little motor and it gets confused you gots to WOT to try and save it...that kind of sound...

when i lower it to the 2 needle slot (from top to buttom), the motor does that same sound more....in the setting right now (top of needle) at least you can accelerate from iddle and get some torque.

but! the iddle seems too accelerated to me, i can release the clutch and the bike will continue, not fast but you know its right there no need to accel more....it maybe normal you tell me.
also heres the weird part on my iddle ...it sort of gos from accel to low rpm with a bit of delay, just slight.

cheers friends!

edit:

the iddle, if i unscrew the iddle more the motor starts dying.