Muffler Issues

C

cruiserdude

New Member
i have a 50cc chinese motor w/ everything stock. Lately ive been hitting the max on the bike @ 26mph but on the last tank of break in using 16:1 ratio mixing. The Black Muffler sounds like it backfires while i twist the throttle staying under 20mph. It sounds like a Big Thump of Air that occurs sequentially til i let go of the throttle. After 20mph i cant really hear it. The Small Socket Screw by the Tip seems to be on there fine. What else could be the problem? Where can i buy a performance muffler to replace it?
 
thump thump thump thump thump thump , really fast. Instead of a smooth vrrrm vrrm vrrm vrrm vrrm i hear small ongoing backfires. thats really the best i can describe it. you cant notice it once you hit 20mph but its still loud. sounds like somethings loose in the muffler
 
I remember once I took my baffle out of my pipe to see how it would sound.
It sure gave that out a thump thump sound and I put it back in right away. I wonder if the insides of your pipe fell apart?
Only other thing that comes to mind is fuel, carb, and a short in your spark plug wire.
Does it back fire if you are moving fairly fast and then you let off on the gas and coast?
 
yup it sure does, if im going real fast and i suddenly coast at a speed you will hear it a lil, not loud enough for anyone else, but annoyin to ur ears lol. i know i recently had that mufler paint melt on me from how hot the muffler got, that thing stunk badly.
 
if its a cat muffler its probably the cat lighting off unburned fuel/oil and that will get very hot and can melt the cat inside but I don't think it will harn the engine just burn out inside then it will be just a muffler
 
well i cleaned the spark plug a bit until my NGK plug comes in , but i dont wanna switch my mufflers because the other one is chrome and im workin on the other build, if anything ill just buy a replacement black muffler for this one.
 
Last edited:
I would try that chrome muffler, it's only two bolts and is the old trouble free style.
You can't ask for an easier way of being able to test things out. If it helps-problem solved!
Don't know anything about the Catylitic mufflers but I have heard of others with problems. What Norman says could be very true, which brings us back to my question and your answer. I'm thinking you are getting too rich a mixture or too much fuel and you have unburned gas. When we were teens we used to turn the key off on our cars, coast for a few seconds and when we turned the key back on, it would let off a back fire like you never heard....BOOM! When I thought about your problem, you reminded me of those stunts.
 
ok , ill change the black muffler with the chrome one and see if it gives a smoother ride. Could the backfiring be caused by a 30 minute ride on GAS ONLY. I ran out of gas but all i had was the gas station near by where i filled up my tank, but no Oil. but when i got home i put 4 oz of oil. Ill change the muffler and see what happens.
 
I'm speechless!
Dude, don't ever do that again, carry a little four oz. bottle of oil with you.
Even some motor oil would have been better than nothing. I would not even dream of running without oil. You really need to be made aware of how important that oil is.
Please don't ever do that again, you are so, so lucky that it didn't seize up on ya.
 
haha you guys act like i put orange juice in my tank , lol. it was Unleaded gas, which all motors need to run, as i understand the oil is just to lubricate and clean the engine. So the half hour ride didnt hurt it, I added the oil once i finished my ride.

As i understood from the motor instructions...you could use 3oz instead of 4oz of oil after break in period? is that true? im still on my 16:1, in this case, after this tank of gas i jump to 25:1 which would be 3oz oil on a full tank.
 
Last edited:
cruiserdude said:
haha you guys act like i put orange juice in my tank , lol. it was Unleaded gas, which all motors need to run, as i understand the oil is just to lubricate and clean the engine. So the half hour ride didnt hurt it, I added the oil once i finished my ride.

As i understood from the motor instructions...you could use 3oz instead of 4oz of oil after break in period? is that true? im still on my 16:1, in this case, after this tank of gas i jump to 25:1 which would be 3oz oil on a full tank.
Click to expand...


You have to be kidding me.

I made this account so I could reply and say how stupid it is to run a 2 stroke motor with out 2T oil in the fuel.

As you under stand the oil "just" lubricates the engine...is that all? sheesh why even use oil, after all it cost money and all it does is "just lubricate the engine".

You're lucky that running 16:1 previously left tons of oil in your crank case and also your lucky for the fact that you can drop these pistons into the barrel (terrible tolerances) other wise your motor would be a write off.

As for your future oil ratio, why not try "New Piston":1 and see how that goes, it surely must be better than 1:0!
 
DIYMark said:
You have to be kidding me.

I made this account so I could reply and say how stupid it is to run a 2 stroke motor with out 2T oil in the fuel.

As you under stand the oil "just" lubricates the engine...is that all? sheesh why even use oil, after all it cost money and all it does is "just lubricate the engine".

You're lucky that running 16:1 previously left tons of oil in your crank case and also your lucky for the fact that you can drop these pistons into the barrel (terrible tolerances) other wise your motor would be a write off.

As for your future oil ratio, why not try "New Piston":1 and see how that goes, it surely must be better than 1:0!
Click to expand...

dang man sorry but that just blew my mind right there...i didnt understand any word you just said. If you would like to elaborate, this is why were here. r.ly.
 
I'd rather put orange juice into my bike than run with no oil.
welcome to the site DIYMark, your "entrance" has got to be a first so that is cool.
No more lurking!
 
Elaborate...well...

It just sent shudders up my spine knowing a 2 stroke was run with out oil for 30 mins! lol

But what ever you do, don't do it again. Your engine NEEDS that oil and more than ever when your wearing in the motor.

If for some reason you fill up at a gas station and don't have any 2 stroke oil or money to buy some - at least use the "courtesy" oil they offer for top ups as "replacement 2 stroke oil". Just add as much as you would if it was 2 stroke oil and away you go. BTW plain motor oil works well as 2 stroke oil (maybe even better) however, it does not burn so running it in your engine for long periods (years) will clog up the exhaust/engine.

Your very lucky that the engine still runs!
 
Last edited:
You must log in or register to reply here.
Back
Top