Any time you replace a piston and rings or a new cylinder your rings will have to seat. Seat mean wear of the little imperfections on the rings and cylinder so you have constant contact between the two.
Lack of power and speed can anyone help?
- Thread starter KoolBreeze420
- Start date
Most all 2 strokes will have some carbon build up when running break-in oil ratios. I would'nt worry about changing the piston rings and cylinder till they are needed. And no the head does not have break in, it has no moving parts so if it seals good and holds a spark plug secure its job is done.
I think this new muffler is clogged somehow I can take the muffler off and the bike runs load and fast she also doesn't idle properly with the exhaust off and the idle screw backed off is this normal or do I have 2 issue's. 1 being a plugged exhaust and the other in the carburetor, after our last conversation I found the piston was sticking when it got to the bottom of the stroke so I took a closer look and found that one ring had a small chuck broken off so I replaced the piston the cylinder body and the head of course I also changed both rims part of the issue was caused from having ceased bearings in the axles.
Currently it will start but wont run with the exhaust on it will only run with it off and I am not sure if there is a fix or if I need to buy another fracking muffler.
Currently it will start but wont run with the exhaust on it will only run with it off and I am not sure if there is a fix or if I need to buy another fracking muffler.
Pucker up those lips and blow on that muffler. Dang easy way to check bad restrictrion on a engine this small. In the Auto shop we had a guy that would use the blast tank from a tire matchine. Would do it to a car every once in a while. That is a bit scary. Still not convined it was right half the time?
Update: The new muffler must be clogged I managed to find my old muffler it is missing the end cap. Here's what I did I took the new muffler off and put the old muffler on I then went for a ride and it was not running correctly but at least it ran.
I let it cool then I looked at the carburetor I took it off removed the idle screw and noticed that the barrel did not go all the way down so I concluded that the throttle cable was too tight so I adjusted the various position's until the barrel went all the way down I then put the idle screw in and I turned it until the barrel lifted up a little then while I had it off I turned the throttle to check that it went up and down and it did so I put the carb back on I then went for a ride and when she warmed up I had throttle control She idle properly she is fast she is finally acting like a gas engine bike not perfect but damn close so I installed the new carb neck and the boost bottle. Now that I believe I have all the other issues solved if I put the new muffler on will the engine be able to clear the clog??? I just bought this clogged muffler April 4 ever since I put it on I have had issues but I didn't understand nor even thought it could be the brand new muffler.
I think. "Correct me if I am wrong" but I believe this new muffler was defective and that it is the sole cause for everything that happened becasue of the clogg, the pressure blew the spark-plug out of what may have been weak threads, causing me to have to replace the head, after I replaced the head I started this thread....
Opinions??
I let it cool then I looked at the carburetor I took it off removed the idle screw and noticed that the barrel did not go all the way down so I concluded that the throttle cable was too tight so I adjusted the various position's until the barrel went all the way down I then put the idle screw in and I turned it until the barrel lifted up a little then while I had it off I turned the throttle to check that it went up and down and it did so I put the carb back on I then went for a ride and when she warmed up I had throttle control She idle properly she is fast she is finally acting like a gas engine bike not perfect but damn close so I installed the new carb neck and the boost bottle. Now that I believe I have all the other issues solved if I put the new muffler on will the engine be able to clear the clog??? I just bought this clogged muffler April 4 ever since I put it on I have had issues but I didn't understand nor even thought it could be the brand new muffler.
I think. "Correct me if I am wrong" but I believe this new muffler was defective and that it is the sole cause for everything that happened becasue of the clogg, the pressure blew the spark-plug out of what may have been weak threads, causing me to have to replace the head, after I replaced the head I started this thread....
Opinions??
What I am getting at is if I am correct and all of the issues can be caused by a defective muffler then maybe I can get it replaced without spending more money, if I am wrong about what I think may have happened then I have to buy a new one, I would love to put the cap on my old but the screw that cap nut screws on to broke this is why I bought the new one.
Some times you have to be creative when something breaks. One of the guys that I ride with also works where I do, once his cap came off after the center mounting stud broke. He made it to work but barely. We found a chrome cap in our plumbing supplies, we then drilled two 3/8 holes for exhaust and attached it to the muffler with two drill screws. It worked so well he is still running it, that was two years ago. Every male here probably has seen the cap I'm talking about, it is a cap for a manual flush water control.
The muffler from my vendors costs 24.95. I have not found one cheaper anywhere.If I am correct and I believe I am that defective muffler cost me hundreds of dollars.
Canadians may be a little nicer when it comes to issues like this.
That defective muffler caused issues that should have never happened.
I only use my bike for shopping I may ride it 2 or 3 times a month so if there is an issue with a part it takes awhile before it shows itself.
The muffler caused the sparkplug to pop breaking the head and then it snowballed from there into a money and frustration pit. When I put the new head on I had lost speed and power hence this post as I tried everyone's suggestions I also tried many things myself I bought a new bike becasue it was cheaper then buying the parts separately 2 of the cheapest rims would have cost 110.00 and I bought the new bike for 110.00 but I though maybe my bearings where starting to seize and causing the loss of speed so I got all new parts and put them on my bike it had no effect, then I bought the boost bottle replaced the throttle the clutch cable the piston the cylinder body all the gaskets and the clutch pads.all of this cost me 118.35 so that's like $228.35. When all I needed to do was replace the brand new muffler.....
Last edited:
I wish you luck with that.
I doubt even a totally plugged muffler could rip a plug out of the head - I'd guess you cross-threaded it at some point. I'd also guess the lack of power to be due to scoring on the cylinder wall due to pieces of the damaged threads getting caught in the rings and dragged by the piston. Just a guess tho.
I doubt even a totally plugged muffler could rip a plug out of the head - I'd guess you cross-threaded it at some point. I'd also guess the lack of power to be due to scoring on the cylinder wall due to pieces of the damaged threads getting caught in the rings and dragged by the piston. Just a guess tho.
I believe that the threads were weak it's the only thing that makes sense. I bought the muffler I installed and I started having problems right away. I chalked it up to the muffler being new and needing to be broke in.
Everything leads back to that muffler the back pressure had to go somewhere so it must have popped the sparkplug out if not then tell me why everything leads back to that point in time coincidence?
I doubt it. Since the beginning of this thread I have been chasing a problem the piston ring broke after I changed back to the old cylinder body and tried to start it you can see that in this thread.
I can find no other reason for the events leading to all of what happened if you have a better theory then spit it out..It has to be the muffler or something out if it's not the muffler then it should start and run when I put it on and it doesn't the loss of speed is becasue the muffler was still partially working. There could be one other factor with this the head gasket when I took it off had a sliver of metal creating a gap, when I tightened the cylinder head bolts I closing that opening, that combined with a clogged muffler the pressure had nowhere to go therefore popping the sparkplug out.
There is no scoring there is nothing wrong with the cylinder body in fact the cylinder body the piston the rings and the head are brand new...
The old piston and cylinder body are also fine.
I sent this thread to my vendor and he has just agreed with me and is replacing the muffler for me.
The muffler couldn't cause the plug to blow out, the compression did. If the engine ran at all exhaust was escaping , the head probably had bad threads from the start. Which plug were you running? The stock kit plug sometimes fit a little loose.
Let me explain the day the plug popped I bought a torque wrench I torqued the head down to it's recommend settings then when I went to start it the plug popped. I ordered the rebuild kit which kicked off this thread and have been chasing a problem loss of speed loss of power now a no start unless I remove that muffler.
As I has said correct me if I am wrong but torquing the head bolts in itself couldn't cause the plug to pop, right?
Now if we combine a plugged exhaust, new exhaust gasket and the head bolt tightening then we get a back compression on the start and pop goes the plug. Logical or not?
Look I am asking and am desperate to understand what happened, in computers when I trace a problem and get back to event one then I can tell you what happened following the same troubleshooting logic it all starts with a new exhaust, gasket and tightening the head bolts.
Yes the one that popped was all stock I am sure that the threads were weak or it would have happened again when I tried to start it but it has to be either these 3 things combined or something else that I don't know about everything I have learned from here though points to these 3 things being the cause perhaps there is some other thing I am missing this is why I am asking questions and why I always say correct me where I am wrong.
As Greg said the muffler couldn't make the plug 'pop', the head must have had a weak thread.
Put a garden hose in the inlet of your old muffler, it will soon tell you if it is blocked.
A Squish test is easy to do to check piston head clearance.
Put a garden hose in the inlet of your old muffler, it will soon tell you if it is blocked.
A Squish test is easy to do to check piston head clearance.
The muffler is plugged that's not in question anymore, I want to know if a plugged muffler can pop a weakened plug and if not then what
Ever since I got the new muffler I new something was off this is what lead to me buying the torque wrench I thought maybe it was time for them to be tightened as the manual said. I figured escaping compression was the problem so I tightened the head bolts and pop went the spark plug.
This is when the problems seemed to be mounting on top of each other, after replacing the head the next 2 or 3 rides had major power and speed loss went through a bunch of stuff like new piston, rings, muffler gasket, throttle, clutch pads and cable, cylinder body, spark plug, new gas, carb rebuild, and new rims and when all was done refused to even start , leading to me discovering that removing the exhaust allows it to start.
This exhaust is basically new since I have been unable to ride it anywhere I bet it has less then 25km on it everything leads back to me replacing that muffler I replaced it tightened the head bolts and pop so if it had no effect at all then O well but I just have a hard time believe that it plays no part it what happened..
When the piston goes up then back down and the exhaust port is completely blocked where will all that compression and pressure go, if not out the weakest part being the weakened plug threads?
Last edited:
Have you tried to clear the blockage in that muffler? Just curious as to what is/was causing it to be blocked. The only other thing that came to mind for me would be if the top of the piston connected with the bottom of the plug and "kicked" it out, but you'd see signs of it (impact damage on the piston) when you pulled the head off.
What was the old plug?
What is the new plug?
Is it a slant head or a straight head?