Back home eh? COOL !

We are accepting new orders for Sleeper Pipes !

Turnaround time is approx. 2 weeks once we receive your pipe.

Below is our current price list

1969-1973 CT175 $199. usd
1969-1973 DT250/RT360 $229.
1974 DT250/DT360 $239
1975-1976 DT250/DT400 $239.

You can message me here or email me at This email address is being protected from spambots. You need JavaScript enabled to view it.

Thanks everyone for your continued support !

Where are you in the UK?
For porting with stable results contact Mick Abbey or Graham File.
Mick also makes pipes.
Next step if you haven't already done it is get rid of weight.
If you still not happy, cheat!

I am in the U.S.

Happy New Year !

We are accepting new orders for Sleeper Pipes !

Turnaround time is approx. 2 weeks once we receive your pipe.

Below is our current price list

1969-1973 CT175 $199. usd
1969-1973 DT250/RT360 $229.
1974 DT250/DT360 $239
1975-1976 DT250/DT400 $239.

You can message me here or email me at This email address is being protected from spambots. You need JavaScript enabled to view it.

Thanks everyone for your continued support !

Hi Meis,

I'm curious, a while back you guys told me you could not do the sleeper pipes for the '77/'78 400, and I was wondering why?
Is it lack of demand, technical feasibility, or some other reason? Since I'm planning on doing a MX/YZ 400 top end, a more appropriate pipe would yield major dividends. If I have to do it myself I will take the time to relearn to weld but if there are any gotchas in the way, I'd like to be aware ahead of time.

Thanks! Dave

Here's an answer given a while back... yamaha-enduros.com/index.php/forums/perf...uros?start=150#71984

They might be able to do something special for the cylinder you're using? I know a few people are probably interested?

We had one sent to us for modification and based on the design it works decent from the factory....there is no place for us install a sleeper cone that would improve performance.

That's the short answer.....sorry we cant be of help!

Ah! Okay that explains that. Sure wish P/S Engineering would respond to their messages. I have a '76 IT400 pipe I may try to re-route (the petcock is in the way). Time to go clean that 38mm carb and get the YZ400 cylinder prep'd.

Thanks! Dave

If the pipe proper is already not so bad, the best short cut may be to just shorten the head pipe a little so it comes in phase with the cylinder at a slightly higher RPM.

Thanks to that Link to the cutaway of the stock muffler, that's very instructive. Has anybody opened up the pipe it's self, what's it like inside?

Dave