Exhaust Exhaust Port- Muffler-Gasket

[BoltsMissing]

Gohst

Just because something is wrong doesn't mean you have to live with it. I took a dremel and ground the pipe to match the exhaust port and modified the gasket accordingly. It was easy and improved performance.

That is the conclusion I have arived to,
match the pipe to the engine, and leave the engine's exhaust port as it is, maybe a light polish, but by no means change the shape.

My direct supplier has had the same issue for 2 years, they hit a brick wall when asking the same question in HT Land. They won't change.

At the moment my 50cc HT runs like carp with the standard fittings, when I tried a modified/dremelled header to an approximate size of the exhaust port, I had better uphill performance with 95 octane 20:1 mix.

I'm going the way of matching the header to the port, perhaps a seperate attachment similar to the carby manifold.
I wonder if that wil fit after it's dremmeeled ?

Sparky, yes, correct if it ain't broke don't fix it is good advice, but some of just can't help ourselves, we must tinker the tinkerables, in the genes type of thing.
You may as well then say why invent the wheel when our legs walk anyway ?
And to add salt, perhaps the HT wheel is square ?

 

[BSA]

If you've drilled holes in the exhaust baffle, by all means muck about with the ports. If you have a standard exhaust it's probably not worth it becuase there is a very large amount of backpressure from these mufflers; if you had an expansion chamber or a very low backpressure exhaust porting would definately yield an increase in performance.

However be warned that making major changes to these engines will lead to parts wearing out more often. Most of these engines are sold with a chromed aluminium cylinder sleeve, which means that you cannot do a rebore. Also warranties would almost certainly be void and believe me, seasoned engineers like Dax would be able to spot if you'd been doing porting.

BSA

 

[BoltsMissing]

BSA
Those thought have passed by, to purposefully de-tuned.
Which is ok to a point.
Had these engines been built correctly and retain a reasonable potential, we minimize downtime on constant maintenance and fixes.
It's as if ya got to have 2 identical bikes, one working while the other is on stand-by after it's fixed cos the one ya riding is gonna go soon to.

3 identical bikes on the constant go would be ideal, it's still a cheap option if you ride one at a time till it inevitably breaks down. Simply get on the
2nd and fix the 1st bike. Then ya got the 3rd to give ya that space incase the 2nd stuffs up, while fixing the 1st. Then fix the 2nd after the 1st, by that time the 3rd stuffs up, and ya back on the 1st.
I think I have it figured .

 

[sparky]

If you've drilled holes in the exhaust baffle, by all means muck about with the ports. If you have a standard exhaust it's probably not worth it becuase there is a very large amount of backpressure from these mufflers; if you had an expansion chamber or a very low backpressure exhaust porting would definately yield an increase in performance.

However be warned that making major changes to these engines will lead to parts wearing out more often. Most of these engines are sold with a chromed aluminium cylinder sleeve, which means that you cannot do a rebore. Also warranties would almost certainly be void and believe me, seasoned engineers like Dax would be able to spot if you'd been doing porting.

This is my point. I don't see the point in trying to increase hp in something that wasn't designed too well to begin with. As someone stated, it will increase rpms, which isn't that smart considering all the problems happy times create. If you really want to tinker, build it from the ground up... otherwise, you'll prolly waste time doing something that'll make the engine louder and wear it down quicker.

But by all means... do what you want.

 

[BSA]

On a completely stock engine, porting isn't going to make any difference in horsepower, you need to have a custom high performance exhaust pipe and muffler. That is what a number of members have done here, and that will give you a HP boost.

I'm interested to see what happens with this experiment. As for my comments I'm not trying to say don't bother, I'm just trying to point out the fact that wear will increase. It's fine to port racing engines, but not your everyday commuter bike. I'm just trying to tell people what to expect. I don't want anyones engine to fail when they rely on it to get to work.

BSA

 

[BoltsMissing]

Well, for me it's the everyday hill climbs in the suburb I live. Mile long hill climbs to get home from errands.
It get's there, but struggles.
That's the power range I only want to explore and understand fully there is a limit on these.

 

[BSA]

While copying old engine threads from the frame mount section to the new 2 stroke section I found this: http://www.motoredbikes.com/showthread.php?t=4296

BSA

 

[RedGreen]

That is interesting, Thanks BSA, I have an extra pipe laying around I think I'll make some adjustments to it.