I have a 66cc 2-stroke. This morning i noticed that the bolt holding the end of the muffler on was loose. I decided to undo it and it was stripped. I got it out and the end part fell off (don't know what its called). I decided to try it without putting it back on. It sounded awesome and louder and I think it accelerates faster too. I live in the country so I am thinking of just leaving it off. I have a boost bottle on it and i've heard that helps with back pressure. I'm not too worried about cold air because the header is probably a foot long. Are there any advantages or disadvantages to this.
Running 2-stroke with header but no endcap
- Thread starter Seth66
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FurryOnTheInside
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I believe it could just be compensating for the real problem, rich condition, caused by the carburetor jet size and needle position and the restrictive air filter box.
But a mild rich condition is no bad thing during the break-in stage, it has benefits.
I believe you need the end cap and it would be wiser to replace the bolt and just experiment with shortening the internal stinger (the small tube that goes through your muffler's end cap) to reduce the back pressure but still have some back pressure. It's a two stroke engine, it's supposed to have some back pressure.
The needle in the carb can be lowered by repositioning the C clip to the next notch up. The stock jet is usually fine for break-in stage because a little bit rich makes for better lubrication and cooling, but you might try a #68 later on, after your engine is properly broken in.
The stock air filter box is restrictive though the filter inside is not particularly effective, so that can/should be upgraded to a nice big foam filter or one of those "K&N looking" filters, so the filter doesn't restrict or choke the intake airflow.
The boost in power that you will get after break-in stage from correcting of the mild rich condition (that was good for breaking in) is presumably what capless stock muffler is mimicking. But the capless stock muffler isn't quite the right way of getting there, and it may be too soon to be running the engine leaner and hotter anyway.
But a mild rich condition is no bad thing during the break-in stage, it has benefits.
I believe you need the end cap and it would be wiser to replace the bolt and just experiment with shortening the internal stinger (the small tube that goes through your muffler's end cap) to reduce the back pressure but still have some back pressure. It's a two stroke engine, it's supposed to have some back pressure.
The needle in the carb can be lowered by repositioning the C clip to the next notch up. The stock jet is usually fine for break-in stage because a little bit rich makes for better lubrication and cooling, but you might try a #68 later on, after your engine is properly broken in.
The stock air filter box is restrictive though the filter inside is not particularly effective, so that can/should be upgraded to a nice big foam filter or one of those "K&N looking" filters, so the filter doesn't restrict or choke the intake airflow.
The boost in power that you will get after break-in stage from correcting of the mild rich condition (that was good for breaking in) is presumably what capless stock muffler is mimicking. But the capless stock muffler isn't quite the right way of getting there, and it may be too soon to be running the engine leaner and hotter anyway.
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I have had it just under a year. It is kind of my junk/hobby bike that I just mess around on anyway. I noticed today when I went to put it back on that the new bolt wouldn't tighten. I think the nut it screws into is stripped. I also think my top speed went down. I think it also uses more gas.
Frankenstein
Deceased - Frankenstein 1991 - 2018
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If it's a junker and nobody will be bothered then do it, not a big deal, it will use more gas because you are just chewing through it and spitting out probably half of it unburnt. Higher rpms will pump more gas through than lower ones naturally, the engine is a pump after all.
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