So I have this Dax engine

[HumanPerson]

Well, that hasn't been my experience on Yamaha Blaster engines, which are reed valved.
I found I could tune the powerband with the intake length and shape.
The stock Blaster intake was perfect for 7000-8000rpm, and we could alter it from there.
An aftermarket intake my son bought was a real turkey, too long and sharp, had to be modified to work.

Resonance will still work for you or against you, even with reeds.

I tried a couple intake extensions and have found that 1.5" of heater hose gives me what I need at this point as far as climbing power and low speed oomph, so far, keep your fingers crossed.

Has anyone tried the JNM Modified Voo-Doo exhaust versus the SBP exhaust system? Kind curious how they compare.

thanks guys

 

[HumanPerson]

I have another speed demon small expansion chamber and small muffler that i am going to modify with a longer header by about 1.75 inches, ave already got the flange brazed on and the hole reamed out on the sides and a little on the top and bottom, angled to match the exhaust port.
I'll probably wait until saturday to cut the speed demon up and braze it all back together.
Thinking about turning it a little bit when i place it onto the longer header pipe then adding about 5 inches of some pipe to direct the exhaust down and away from my rear tire.

what do you guys think? will this work?

 

[HumanPerson]

ok FurryOnTheInside,
i got the speed demon expansion chamber/exhaust and cut the pipe off of it and had to remove another 6+ inches of pipe sticking inside of the new exhaust Got it all brazed up with a couple 45 degree fittings and manuvered into the position that i want it and let me tell you i get to 29MPH pretty quick now and hills?!?! what hills!!! The big hill i could only creep up at 17 MPH i now got up at 23MPH without peddling, which is quite a plus for me. I had some pin holes that blow some oil out of but i think i'll try some silver solder to close up those pin holes or i may just wrap it all up in the muffler wrap/tape stuff, you think that would be sufficient??

 

[HumanPerson]

I need to get a camera i guess....pics to come soon hopefully

 

[Steve Best]

Pinholes are generally just a problem because of the oil leakage, any bigger than a pinhole will cause problems though. Wrapping it doesn't solve anything it just hides the problem.

 

[FurryOnTheInside]

ok FurryOnTheInside,
i got the speed demon expansion chamber/exhaust and cut the pipe off of it and had to remove another 6+ inches of pipe sticking inside of the new exhaust Got it all brazed up with a couple 45 degree fittings and manuvered into the position that i want it and let me tell you i get to 29MPH pretty quick now and hills?!?! what hills!!! The big hill i could only creep up at 17 MPH i now got up at 23MPH without peddling, which is quite a plus for me. I had some pin holes that blow some oil out of but i think i'll try some silver solder to close up those pin holes or i may just wrap it all up in the muffler wrap/tape stuff, you think that would be sufficient??

Well first I'd like to say there's no need to direct your question at me lol, that "well known member" status just means that I chat a lot. I read the forum like it's my favourite bike mag, which it is.
I have no plans to fit a tuned expansion pipe to my build because I have to be stealthy and can't do any mods that detract from that priority. I do hope that a simple seal like your silver braze held in securely by wrap will be sufficient. I have to seal up the end cap on my stock muffler when I extend the pipe with sound absorbent silicone hose (a la Fabian). I was thinking of JB Weld with wrap over it so it can't go anywhere.

 

[HumanPerson]

Pinholes are generally just a problem because of the oil leakage, any bigger than a pinhole will cause problems though. Wrapping it doesn't solve anything it just hides the problem.

yeah the oil leakage really gets under my skin
Hopefully they seal themselves?
thanks Steve

 

[HumanPerson]

Well first I'd like to say there's no need to direct your question at me lol, that "well known member" status just means that I chat a lot. I read the forum like it's my favourite bike mag, which it is.
I have no plans to fit a tuned expansion pipe to my build because I have to be stealthy and can't do any mods that detract from that priority. I do hope that a simple seal like your silver braze held in securely by wrap will be sufficient. I have to seal up the end cap on my stock muffler when I extend the pipe with sound absorbent silicone hose (a la Fabian). I was thinking of JB Weld with wrap over it so it can't go anywhere.

Every answer is a potential stepping stone in this motorized bicycle situation.
I wanted to quiet my bike down alot too so i cut up and modified the speed demon muffler with some 45 degree elbows but i didn't have the silver solder so i used the bronze brazing rods which worked well but i have these oil leaking pin holes which get under my skin haha
so now i have some steelweld stuff on the joints where the pin holes seem to be coming from lol i was just wondering though if the steelweld and if i wrap the exhaust and not the header after the steelweld cures, if that would suffice. I also read last night that the pipe can be tuned with the wrap if only wrapping the expansion chamber and about an inch or two of my header pipe while leaving 5 or 6 inches of my header pipe unwrapped. what i gather is that the sound deadening will be quite noticeable while helping with low rpm torque.
in could be wrong though lol
we seem to think along the same lines though FurryOnTheInside, keep us posted on how your stealth build is going.

 

[FurryOnTheInside]

Every answer is a potential stepping stone in this motorized bicycle situation.
I wanted to quiet my bike down alot too so i cut up and modified the speed demon muffler with some 45 degree elbows but i didn't have the silver solder so i used the bronze brazing rods which worked well but i have these oil leaking pin holes which get under my skin haha
so now i have some steelweld stuff on the joints where the pin holes seem to be coming from lol i was just wondering though if the steelweld and if i wrap the exhaust and not the header after the steelweld cures, if that would suffice. I also read last night that the pipe can be tuned with the wrap if only wrapping the expansion chamber and about an inch or two of my header pipe while leaving 5 or 6 inches of my header pipe unwrapped. what i gather is that the sound deadening will be quite noticeable while helping with low rpm torque.
in could be wrong though lol
we seem to think along the same lines though FurryOnTheInside, keep us posted on how your stealth build is going.

I can't see that there's anything to lose by trying this steel weld on the header-to-elbow joints. I would go for it.
I'm not entirely sure what you mean or what the post you read meant. Maybe just that you'll need a bare header pipe to be able to experiment with the length, and then you can put more wrap on it later when you are happy with the length?
I think I did read about an extended header on the stock pipe being good for a bit of extra low end torque. I will have to see how it all fits on my bike before I can say whether I'll be attempting to extend the header on my own stock pipe. I'm still waiting on mount studs and bolts.

 

[HumanPerson]

some pictures here, let me know what you all think, i can use some critisizm