1976 Yamaha DT250 Hand-Made Expansion Chamber

[@ducatipaso1386]

Narrow peaky power band is because motor don't have a "power" (exaust) valve. 2 stage reeds help a bit. Pipe & port moves the sweet spot.

[@coachtwostroke5660]

omg it sounds like a blaster!!!

[@ashleylloyd7445]

Looks and sounds beautiful, I bet it sings

[@JohnnyLee8355]

Sounds great👍👍

[@hugieflhr03]

I know this is an old video but was this exhaust a big improvement over the stock one?

[@PucketyCrik]

I have an old book that shows how to make 2-stroke expansion chambers and all the calculations

[@bobswagger8169]

2 stroke tuners handbook by gordon jennings

[@tacticalmosquitoeater]

I'm getting a '69 dt1 also hoping to do a exhaust modification. Great job!

[@Legardi]

Holy shit that sound reminds me of when I was 14.

[@exlonghauler]

Nice work !!

[@omarzp15]

sounds damn good

[@jessemccoy1661]

Any power improvement, or only noise?

[@jimsgasgas]

sounds great!

[@DeeJay86dk]

You have a plan/schematic yoy want to share for this? :)

[@ortan191]

sounds good man

[@dennisharrison3114]

I had a couple dt's like yours the motor at least put it on a 78 yz 400 frame had another one same set up I made a expansion chamber for it to the first one I built actuly had the yz 400 pipe it ran like a yz awsome woods bike

[@jonmcginty1575]

could you give me the guys contact info who made this? i have a 76' DT400 in need of a pipe/silencer out in California.

[@Kevin-z9y2b]

What sparkaresstor is that

[@seelder]

amazing

[@reillystsb]

I tried that same pipe on a DT 250 and DT360A did not work ! stock pipe had all around better performance (expansion chamber killed low-end power)

[@caferacer7]

Hi John, Did you have the other pipe that was produced at the same time? I was one of two people who had purchased a pipe from a guy who seemed to be genuinely trying to help provide quality hand made pipes on the yamahaenduro.com forum. However he was not the guy making the pipes, as it often goes. He was a salesman, and I don't think any actual testing was done. You are right, the pipe made the DT very peaky. I do not know enough, but I think it may need a longer runner from the head to the begining of the expansion, and also the chamber itself may need to be smaller. Also, I had planes to try an MX250 cylinder and head, designed for a little more top-end flow. If the pipe was made right, I 've heard that is a great combination with a DT bottom end / heavier flywheel. We honestly just wanted lighter hand-made pipes with a little better performance than stock. The stock pipe is very heavy! Bassani used to make pipes like we requested, why he could not just copy the Bassani idea, we will never know. They thought they could do better. I orininally uploaded this video to host and show forum memebers after the pipe was installed. I no longer have the bike, but I do still ahve the pipe! I am impressed with the interest. I have since learned to tig-weld myself, and met a local friend who could build expansion chambers. I don;t know that we could reinvent the wheel, but we could certainly produce a copy of a known working, but no longer available design, like the Bassani. I am amazed at the interest this has generated over the years!

[@reillystsb]

caferacer7 Like a bassani smaller expansion chamber might make better power

[@reillystsb]

It is a good looking Expansion chamber

[@warriordriver350]

Nice sound/ look u should try sanding it down and painting it like a chrome color than it would look real neat and the motor could use some touch ups to but te rest of the bike looks great!! How much did u pay or is he a friend who did it for free?? I'd like a pipe like that once I'm finished restoring my DT check out my videos of it.

[@Ben-rm9jx]

what a difference from stock

[@matthew1er]

Nice

[@michaelmays9292]

Fun play bike

[@megabaconman321]

nice

[@MikeSmith-ve2qu]

My friends laugh at me but when i bring my 1982 CR480 they shut up quick.

[@michaelmays9292]

To small

[@Sadboylokee]

I have one mine is way better than urs my guy

[@Sadboylokee]

Run more better