Hey im new... thanks...

[mckennanite]

New to the "hobby", new to the forum... i was wondering, and this may be more appropriate somewhere else but... i recently installed my first china 2 stroke, gotta expansion exhaust early on, vibrated off... yada yada yada. after i got my exhaust bolted back on I immediately noticed a decrease in power, i ran 2 days w/ no exhaust at all, loud yes! but the performance was alot better without the expansion chamber exhaust. any vets here know what this may indicate other than the obvious (less restriction/more power...) what i should look at improving next? gotta offset intake on the way for a velocity stack cone filter type air filter upgrade... thanks in advance for any help....

-Josh

 

[Timbone]

These little engines will run fine with no exhaust or with no air filter. But it's not smart to run them this way.

I hate the way the exhaust hooks up with two thin 6mm studs. You cannot allow on those two studs to support the exhaust pipe. Use something to support the exhaust. I have rigged up a small lawnmower muffler on there and it works pretty well. A little louder than I would like but this is not the final setup. These little engines are tough on the stock muffler!

I repeat: please don't run free of the muffler. It's too loud and, at the very least, it won't be good for your hearing. Not a good way to display motorized bicycles to your neighbors. And, it is very possible that something could get kicked right into that piston and that will not end well!

Experiment. Lots of ideas on here. At one time I used a soft drink can full of steel wool and it actually worked.

 

[mckennanite]

Hey Tim, thanks so much for the reply! yea, it is reeaaaallly is loud, I'll not run it without it. I'm sure your right about the supporting the thing. thanks, do you think look the stronger loctite does anything to help much? and what do you think I might yield if I took an angle grinder a little up the banana pipe and had a 3/4 inch hole instead of a 1/4 inch hole, the power loss is substantial after gettin it mounted back up, ya know?

 

[Timbone]

My experience with the exhaust is quite limited. I've used the stock unit and a few things I rigged up. I am after practicality and reliability, not concerned too much with looks - and a cool exhaust pipe can really enhance the sound and look of the bike, as well as the performance.

So, I am just saying I am not the best source for info. I will tell you that, yes, red loctite on the exhaust bolts are a great idea and will make a difference. And the earpice of the exhaust where it bolts into the engine stud must be good metal.

I cannot say what effect your hole drilling will have.

Timbone

 

[mckennanite]

Cool, well thanks again for the response... its nice to be here!!