Dt175, should I put an rm125 pipe on?

[Miles Hansen]

I have a 1980 DT125 that I've crammed a DT175 top end onto, im using the stock 125 pipe and I just so happen to have a 1980 RM125 pipe just laying around. The bike has good power all the way across the board but I really like the zingy top end of 2 strokes, I AM willing to sacrifice low end torque and hp for more top end. The dt125 pipe seems to have baffles in the expansion chamber and the expansion chamber does not look like a MX pipe, is making the rm125 pipe fit a good idea? Would i actually see power gains at top end? 

 

Pipe on the bottom is the DT125 

Pipe on the top is RM125 

Edited November 22, 2020 by Miles Hansen
Pictures

[DEATH_INC.]

Doubtful it'd work well, it's most likely far too short for the DTs rpm range.

 

 

[Willie71]

Time to make a custom pipe. There are a few programs out there that can give you the dimensions. 
 

http://www.dragonfly75.com/moto/buy7calc.html

Edited November 22, 2020 by Willie71

[zig06]

Don't bother, if anything you could try to install an IT175 pipe.  But really, you'd be far better off by just making your DT run as good as it can stock.  If you want more power then its time for a new bike.

[burntvalves]

It would be a lot of work, but if you think you can pull it off give it a go.  You will need an angle grinder with cutoff wheels and a mig welder.  

the DT header pipe is clearly a piece of crap.  

it might be happier with the RM pipe, but don't expect a night and day difference.  

[Miles Hansen]

On 11/22/2020 at 12:20 AM, DEATH_INC. said:

Doubtful it'd work well, it's most likely far too short for the DTs rpm range.

 

 

Dt revs happily to almost 10k! I'll probably get to chopping soon. Picking up another stock pipe this week so im not attached to this pipe whatsoever 

[Miles Hansen]

20 hours ago, burntvalves said:

It would be a lot of work, but if you think you can pull it off give it a go.  You will need an angle grinder with cutoff wheels and a mig welder.  

the DT header pipe is clearly a piece of crap.  

it might be happier with the RM pipe, but don't expect a night and day difference.  

I know the difference won't be night and day, im mostly looking for a bit more top end and more of the ring ding ding noises of an MX bike ill keep you all updated. 

[Miles Hansen]

20 hours ago, zig06 said:

Don't bother, if anything you could try to install an IT175 pipe.  But really, you'd be far better off by just making your DT run as good as it can stock.  If you want more power then its time for a new bike.

Stock the bike runs amazing with my IT175 top end and case trenching, probably going to install a larger carb soon and port the jug just a little more. Thr 125 seemed to be a little more rev happy, removing the exhaust and running it without the expansion chamber it seems less corked (and extremely loud) 😛 im only 17 and the best way to learn is trial and error i guess. Ill keep yalls updated on how it runs after the swap. 

[M E T A L A C I D]

I wouldnt, just keep her stock. Just decarbon it, clean it up, and shoot it with some black hi-temp paint...

[DEATH_INC.]

4 hours ago, Miles Hansen said:

Stock the bike runs amazing with my IT175 top end and case trenching, probably going to install a larger carb soon and port the jug just a little more. Thr 125 seemed to be a little more rev happy, removing the exhaust and running it without the expansion chamber it seems less corked (and extremely loud) 😛 im only 17 and the best way to learn is trial and error i guess. Ill keep yalls updated on how it runs after the swap. 

Get an IT pipe for it, that'll match the porting better.

[zig06]

22 hours ago, Miles Hansen said:

Stock the bike runs amazing with my IT175 top end and case trenching, probably going to install a larger carb soon and port the jug just a little more. Thr 125 seemed to be a little more rev happy, removing the exhaust and running it without the expansion chamber it seems less corked (and extremely loud) 😛 im only 17 and the best way to learn is trial and error i guess. Ill keep yalls updated on how it runs after the swap. 

Nothing wrong with experimenting, but eventually you will find that your spending more money and getting less power.  I can say that running a 2 stroke without the exhaust will cost you a big percentage of what ever hp you do have.  

 

[rider58]

Its been known to cut open those pipes and remove the baffling and put it back together and they claim gains in power.