exhausts

[basser23]

Hey Guys,
I was cruising the web looking for some headers for a Skorpion(Bill has mentioned using TDM 850's as a start) when I found OS Pipes in Staffordshire UK.
They have made pipes for all sorts of bikes including Mz using the Rotax 500.
I was wondering is any of you in UK might ring them up for a quote on Skorpion headers 32-33mm id to fit either 2-1 or 2-2 systems...
They are all 304 stainless according to the site,and their prices seem resaonable...by the way some TDM headers avail on ebay uk for 94quid.
OS Pipes can be reached at 44 (0)1889 271818 10am to 5pm...no email
So if anyone is near to the Midlands.......check it out....
Chip

[Bill Jurgenson]

Not a Skorpion but the same 3YF engine, I have rebuilt another customer's engine for his Yamaha SZR.

My "normal treatment":
-Ports modified and enlarged;
-Megacycle 280-2 cam without deco
and with stock valves and springs;
-cylinder bored and honed to 101mm for a WISECO flat top forged piston, not the hi-comp. Raptor piston, this is for the Grizzly and is 1mm higher, necessitating a thicker base gasket which I routinely make from 1,5mm aluminum sheet. I run this same piston and prefer to use it in customer engines unless they really desparately want the 12:1 thing. I am not a fan of such high compression for a street engine;
-lightened flywheel/freewheel assembly;

-Mikuni TM34-B65 in modified stock airbox with K&N;

BTW, compare the size of this stock airbox with the ridiculous thing on the MZ.
-solid balancer gear;

-modified cooling system using FZR600 thermostat housing and filler cap to get a real thermostat-controlled system, something neither the Yamaha nor the MZ have originally;

THe FZR thermostat has three connections, two in the bell below the true thermostat so the coolant from the head goes straight back to the waterpump thru that green garden hose and T-connector until the thermostat opens, letting the water flow thru the radiator which is obviously missing in this pic.
-and of course an Ignitech Sparker programmed to a max of 29º BTDC at 6000 dropping to 27º by 9000

compare:

That nearly vertical advance around 3000 is the reason for the chainlash.
-a new exhaust system utilizing TDM headers I had which I rebent (cold) to suit and cut off to length:

From stainless tubing I had that by lucky chance fit exactly over the TDM pipes I made a Y-piece


and then mated this up to a bought 15ª bend with a 50mm ID slipon end




The Rombo end can es LOUD! but it is the owner's It was already in place with the OEM system botched up to fit. I cut the botching off leaving the connector pipe (for a R6) and can untouched.
The new system widens progressively, starting with the 35mm OD TDM headers (OEM=31.5), the the Y-piece =36.5mm OD siamesed to a 50mm area matching up to the 50mm OD connector pipe.

Weather has not allowed much test riding. I did take it out yesterday for the second time to do some errands to a neighboring town. It starts immediately:
one twist of the grip, no choke, left thumb on button, right hand gas to catch it right off and bums! Since it has no choke, you have to play with the gas at first to keep it alive. Once a bit warmed up, gas response is VERY fast, the engine remarkably flexible, pulling from just shy of 3000 without chainlash. This both due to the very reduced advance but also to the relatively low compression of about 10:1. I set the warm idle to 1800 and it is very smooth.
Fun to ride, it really gets up and goes. Of course I can't really push it yet; new piston and rings.
Once in the other town, it just had to start raining! Riding home, I took it easy, not being familiar with his Pirelli Diabolo tires in the wet. Riding away from a stop sign down a favorite bypass (straight), I didn't push 1st at all but once in 2nd and higher up, pushed to to 7000 is less than no time and this time shifted race-style into third and WOW - CAREFUL: rear wheel spin in 3rd gear with the tach jumping right up almost where it had been and the bike fishtailing a very little (so the tires are alright).
Guess there is enuf performance now to pester the big game on those twisty roads "real gud!"

[basser23]

Nice exhaust! Just the ticket I think for the skorp..TDM headers are available in US from Delkevic..so...Bill do you have a measurement for the wall thickness of
your home made y connector?
Thanks..

[Bill Jurgenson]

The seam-welded tube I used for the siamese piece is 36,5 OD and has 1mm wall thickness, i.e. it has 35,5 ID and thus fits right over the TDM headers as if made for the job. Because of the very thin wall(for stainless), it has gotten blue very fast. I salvaged the tube from the column of one of two livingroom floor lamps which I hate. These columns are made up of three sections, screwed together, so the individual segments are about 18" long each and have a pressed in male threaded fitting at one end and inside threading on the other of course, that makes the lengths shorter;one needs two sections for one Y-piece. I have one section left from that defunct lamp and will have to nudge the other into oblivion sooner or later to put its column to better use.
You ought to be able to grab TDM headers off eBay for nearly naught. Apart from the larger Ø, teh TDM pipes have a much larger radius bend which is much better for the gases - but careful with MZs, there could be problems clearing the radiator. I hat to move mine forward for the Barker pipes on my racer, too.
The other piece behind the siamese pipe is straight-forward car stuff.
You need someone very adept at WIG welding to weld up the junction pipe with that thin wall.
I drew up a 1:1 top view and side view (orthographic projection, remember?), cut the tubes and had my professional friend weld them so that I had two of the same with that ± 15º bend welded you can see at the front end. I them made a jig from plywood to support and clamp one tube so that the long cut would be vertical to the table surface. I then cut thru that pipe with the big bandsaw using the side fence. I then reversed the supports on the jig to clamp the other tube mirrored and cut that one as well. Rolf then welded the two together along that long joint.

shown here just after welding and polishing before determining final length which was done by shortening the end until the 50mmØ equivalent crossection was attained. The bought 15º slipon junction was shortened and flattened to match both crossection and position, the meant-to-be-clamped slotted end was "relieved" of its slots and finally the hooks for the spring were welded on after the system was completely installed. they are not really necessary and there is no spring for the mating of headers and siamese. Likewise, we decided to leave off the frame connection the OEM system has, ltho I had made it ready to weld on, because both Rolf and I hunch that the OEM system cracks (VERY often!) a the welded junction of the two headers because of this fixed point.

This is the original LaFranconi system. Purpose and design of the two headers is something no one really understands; the routing is terrible and there is no reason on this or any other earth to make both exactly the same length since it is only one cylinder. The skinny Ø is also obvious.

this is the Termignoni Cup system mounted on my own bike with a SR-Racing can. It, too, has 35mm OD headers, which are, however slightly larger in ID since the tubing is thinner-walled. Ther are not that many ways to skin a cat; what I made resembles this closely.

[basser23]

Thanks Bill,

I too have an "uplighter" lamp with that same diameter The wife would hurt me if I touched it ......but...I'll search our local "beauty spot" as sometimes
they are plentyful...
Given me a lot of ideas...
Chip

[Bill Jurgenson]

The wife would hurt me if I touched it

same here!! She loves it.
I'll have to "accidently" ruin it somehow.

[Bill Jurgenson]

I found another, better picture of the bike outside in the real world, not on the hydraulic lift:
http://img831.imageshack.us/img831/3990/img2602h.jpg

[Bill Jurgenson]

today, I went to my friend Tim Barker's page for a change. Haven't looked at it for ages.

http://www.barkersexhaust.com/atv-utv-motorcycle-exhausts/ATV/Yamaha/Raptor-660/Yamaha-Raptor-660-Dual-Drag-Pipes.html

these ought to adaptable to a Skorpion without much ado.

[basser23]

True , He has also been receiving loads of emails to build more systems,and has replied in a positive way.
See Wanted Full exhaust and carbs for Skorp thread... 660cc
(I've been eyeing the wife's uplighter lamp,measured the tube and its 35mm+ a little id )

[Bill Jurgenson]

like I said, a perfect slipon fit.

[Old Dog]

What I would like to source is that lovely engine stand in Bill photos.

[Bill Jurgenson]

http://www.kedo.de
60640 Engine Mounting Stand, Zinc Plated
http://www.kedo.de/com/ssl/php/art_deta ... 2618ba9ffa

[Old Dog]

While I am looking at ordering this stand which flywheel puller is the one to go for please?

thanks

[Bill Jurgenson]

none of the aftermarket pullers I have seen specifically for this job are up to it.
You should check out industrial jobbers for something that can fit.
Of course the original Yamaha tool will work but will also be hard to get and expensive.
I made mine. I'll post pics and details tomorrow morning.
Almost three years ago, there was a long thread:
http://www.mzriders.com/viewtopic.php?f=3&t=2268&start=0&hilit=puller

specifically;
http://www.mzriders.com/viewtopic.php?f=3&t=2268&start=0&hilit=puller#p13098
http://www.mzriders.com/viewtopic.php?f=3&t=2268&start=0&hilit=puller#p13102
the thread protector is most important
http://www.mzriders.com/viewtopic.php?f=3&t=2268&hilit=puller&start=15#p13109

One size fits all shown in the thread may work. The ones I have seen over here all bent or broke without budging the thing.

here is simple car hub puller;


Like I explained in the thread above, just a plate with the appropriate holes and center bolt with NF or metric fine thread.
here is something like that to buy:

http://www.tooltopia.com/northcoast-tool-5676.aspx?utm_source=nextag&utm_medium=cse&utm_term=NCT5676&utm_campaign=nextag_r1
Would depend on how thick the plate is.

this one might work:
[
It is certainly strong enuf and the price is OK; you will just have to look and measure it in the store yourself to be sure.
http://www.jcwhitney.com/2-arm-hub-puller/p2007846.jcwx?skuId=220506&TID=231000000&zmam=15972153&zmas=21&zmac=123&zmap=813995

the bolt circle of the flywheel is 90mm = 3,5+"

[TBarker]

Bill I made up a bunch of thread protectors for pulling flywheels off. I have them for $10 they are hardened and flywheel will come off over it.
http://i479.photobucket.com/albums/rr15 ... GA0309.jpg
http://i479.photobucket.com/albums/rr15 ... GA0308.jpg