GPz750 and Motad zorst

Had to replace the original 4-2 zorst on the '83 GPz750 (non-turbot)
at the weekend cos it had rusted in all the wrong places.

Bought a Motad 4-1 as a replacement and, after buying some proper
split collets and some exhaust gaskets, I fitted it at the weekend.

First proper ride today and although it sounds okay there is an
annoying flatspot at 6k.

Has anyone any experience of rejetting for this particular setup?

 

Is the right hand silencer still any good?

 

Not bad. I've had to re-rivet the plate on the back - but apart from
that - it's fine.
Both middle down-pipes and the LH silencer are good
I'm in south Northants.

 

Agreed, that worked for my GPz550H2. Made the bike a lot more usable
from much lower revs.

 

I'm a bit stuck for a temporary jobbie on the turbo while I get a new
twin turbo -> exhaust pipe sorted.

Any chance of having yours if it measures up [1]?

38mm dia and when in position the front clamp area is at least 17mm in
front of the rearmost edge of the lower frame rail VIN - the GPZ 750 does
have a VIN plate there?

See this for what I mean:
http://sweller.dynalias.org/turbo311004/photos/photo2.jpg

 

heh - I hope so.

 

By which I mean I'm getting a pipe made up that goes from the /single/
turbo to two exhaust pipes. Not twin turbos; which is a shame.

 

Using the patented Mavis Beacon "Hunt&Peck" Technique, sweller

Well, look, now you've had the idea...

--
Nigel - Manufacturer of the "Champion-105" range of rearsets

WS* GHPOTHUF#24 APOSTLE#14 DLC#1 COFF#20 BOTAFOT#150 HYPO#0(KoTL) IbW#41
ZZR1100, Enfield 500 Curry House Racer "The Basmati Rice Burner",
Honda GL1000K2 (On its hols) Kawasaki ZN1300 Voyager "Oh, Oh, It's so big"

 

It seems your pipe is a bit short.

Mine seems to bend further around the frame

http://img80.exs.cx/my.php?loc=img80&image=exhaust.gif

(The jagged red line is where the pipe has rusted through)

 

Modern Motads are utter shite. When they ratcheted down the noise
limits, Motad simply seemed to bung their pipes up more. Time was, 20
years or so ago, when a Motad gave exactly the same power
characteristics as OE. Not any more.

After my experiences with a Motad and my old GT750, I'd never buy one of
their systems ever again.

(Statto - have you still got my ShiteOldGT?)

 

The Older Gentleman says...

I don't have much choice for the CB250RS, no-one else makes one for it.
The one it has is rotten as a pear and has been welded about 5 times. I
think it's only about 4 1/2 years old. I first had it welded about 2 1/2
years ago.

 

Modern Motads are utter shite. When they ratcheted down the noise
limits, Motad simply seemed to bung their pipes up more. Time was, 20
years or so ago, when a Motad gave exactly the same power
characteristics as OE. Not any more.[/QUOTE]

Oddly, the full Motad system on the Wing is more free-breathing than
the chromed tissue paper original.

Stainless too, meaning it doesn't corrode, but it's not very shiny.

Oh, and around £550, rather than £1400+.
--
| ___ Salad Dodger
|/ \
_/_____\_ GL1500SEV/CBR1100XXX/KH500A8/TS250C
|_\_____/_| ..73063../..16931.../..3180./.19406
(>|_|_|<) TPPFATUICG#7 DIAABTCOD#9 YTC#4 PM#5
|__|_|__| BOTAFOT #70 BOTAFOF #09 two#11 WG*
\ |^| / IbW#0 & KotIbW# BotTOS#6 GP#4
\|^|/ ANORAK#17 IbB#4
'^'

 

Modern Motads are utter shite. When they ratcheted down the noise
limits, Motad simply seemed to bung their pipes up more. Time was, 20
years or so ago, when a Motad gave exactly the same power
characteristics as OE. Not any more.

After my experiences with a Motad and my old GT750, I'd never buy one of
their systems ever again.

(Statto - have you still got my ShiteOldGT?)[/QUOTE]

Yes. The Motad exhaust really has fucked up the power delivery.
Fuckall below 3k revs, then power is finally delivered. Peakiness can
be fun with the correct bike, but on a shite old shafty? It's slightly
annoying when it's cold, dark and pissing down and all you want is to
get home.

 

Gawd knows what my FZR would be like if Motad ever made an exhaust for
that. 3k? the rev counter starts at that.