3.0 225 working on exhaust

**cvp240** · 11-17-2021, 03:33 PM

Working on the exhaust pull the Cannes out check for water leaks both upper and lower exhaust gaskets look good should I just leave the can out let the exhaust go out the sides

**Chaz** · 11-19-2021, 12:52 PM

You can't "just leave it out". You will need aprox. 8 to 10 inch's of the top half to attach the water tube .

**zxracer** · 04-24-2023, 08:06 AM

Chaz,

Do you have any measurements for cutting the exhaust tube?

I have 2002 3L EFI that works really well except out of the hole and I'd like to cut the "tuner/tube" this year.

Thanks for any help/advice....even your picture is the first good guidance I've found!

Ryan

**Chaz** · 04-24-2023, 11:00 AM

This can is up-side down ...

A good place to start would be just above the lower (highest in this picture) casting line. Cutting it there will connect the front and back exits, as well as the idle relief hole at the back of the cowling. Leaving some skirt will also protect the finish on the outer can.
Cut at that point, the skirt will be under water sitting still at idle. The 300x had "cats eye" holes on each side of the skirt to allow idle exhaust to be vented out side of the skirt.

Or now that you see what you have, you can cut as high as you like (picture from long ago). If you choose to do that, leave the water dumps long to keep water from being pulled into the exhaust logs.

Besides the "cats eye", the 300x also had a hole that connected the two lower exits together. Some guys (their wifes)

still want their motors to run quiet, so I have cut the rear flap off, hole sawed a 2"- 2.250" hole in the center wall, then welded the flap back on.

Lots of different ways to go .. cut it all the way back, or stop somewhere along the way. Whichever suits you the best ...

Me ... personally, I went this route ...

**Dave S** · 04-24-2023, 11:09 AM

CUT EMMM and Cut theme High.....

.......

**zxracer** · 04-25-2023, 08:27 AM

Such excellent info thanks Chaz!

Did you do this to get bottom end, top end, etc?

Any other info greatly appreciated!

**Chaz** · 04-25-2023, 10:15 PM

It's not really one thing that makes power. It's more of an accumulation of a lot of little things.
In his book, Gordon Jennings talks about the primary header and the divergent cone attached to it as being the most critical when it comes to evacuating a two stroke cylinder. I just do my best to follow those who came before me and their proven formula's.

I see some are now asking $150 and more .. for a book that was once $10 bucks ...

https://vdocuments.net/two-stroke-tu...ok.html?page=1

**big tom** · 04-27-2023, 05:10 PM

Thank you much Chaz! I've seen screen shots from it but now I have it.

**Chaz** · 04-27-2023, 11:42 PM

Good mornin Big T.

Jennings wrote another book on just pipes. It was titled something like :
So you really want to know how to build expansion chambers.

Dr. Bell wrote two books. He was more of a numbers guy in the classroom than hands on compared to Jennings .. once I brushed up on long dormant maff ..

his timed area vs. crankcase volume formulas began to make sense.

I found one of them :

https://archive.org/details/A.Graham...uning/mode/2up

**XstreamVking** · 04-28-2023, 06:42 AM

I just got a 250 xs. EX. can removed and just a tuner showing. It is fn loud! Killed the low end power imo. (no ventilation of the prop!) Plan on replacing the can and I will cut it like chaz sez.

**big tom** · 04-30-2023, 11:03 AM

Originally Posted by Chaz

Good mornin Big T.

Jennings wrote another book on just pipes. It was titled something like :
So you really want to know how to build expansion chambers.

Dr. Bell wrote two books. He was more of a numbers guy in the classroom than hands on compared to Jennings .. once I brushed up on long dormant maff ..

his timed area vs. crankcase volume formulas began to make sense.

I found one of them :

https://archive.org/details/A.Graham...uning/mode/2up

Thanks Chaz!

By the way, Tell those big beautiful snow bunnies in the mini vans its still cold up here in Michigan...

**Chaz** · 04-30-2023, 02:04 PM

Big T ,

Back in early 2000's I thought I'd give it a try to become the IHRA Top Dragster world champion. Part of that journey took me to Milan, Martin and Stanton Mi. All three were great places to race. If I remember correctly, it was low 70's in the daytime and 50's at night. Perfect racin and sleepin weather in my book ...

**big tom** · 05-06-2023, 08:58 AM

Chaz it is beautiful up here. I'm about 150 miles north of Martin in leelanau County, Nw side of traverse city in the little finger of the mitten. The water is beautiful but we only get 4 months to enjoy it. When it finally warms into the lower 70's it starts into fall. The summer's have changed. Seems like we don't have a spring or fall anymore. It goes right to summer and it's high 80's and 90s. Last year it was the more windy summer that I have remembered. And dry.