Yamaha 660 what mods can be done

[basser23]

Bill,
Two items, yu say the GS500e wheels are an option..from what I've seen,Katana
wheels are the same..any knowledge of this?
As far as exhaust is concerned,I believe you could make some coinage copying
the Remus or Cup pipes for Skorpion owners..at least an engineering layout with
specs..the Termi's are way pricey for the SZR over here in the states,The alternitive
is the Barkers set of pipes,but then you lose the sidestand..(I have no center stand
on mine)
Thanks
Chip

[Bill Jurgenson]

That has crossed my mind, but frankly, I don't have the time to get something like making exhaust systems started. I pestered TIm Barker for a long time about making a 2-1 system for the Skorpion, something like the Remus. This was back before he went into the business full-time. He might be more interested now. If you and others were to pester him as well, that might help. I know I could sell a couple of systems over here as well, altho they would have to use a European certified can such as the BSM, at least in Germany.

The Termignoni for the SZR cost 800€ which is not expensive at all for a complete system, such as it was. It comprised:
two stub manifolds to accept the slip-on headers;
2 slip-on headers, each different;
1 siamese pipe;
one slip-on back pipe;
one slip-on can;
6 springs for all those slip-on junctions.
all of very thin-walled stainless, very well made and very light. And very LOUD!
I know this first hand since I have the system on the shelf.
It is no longer available from Termignoni.

[Cyclops Hammer]

will a air filter kit like

http://cgi.ebay.com/ebaymotors/YAMAHA-R ... enameZWDVW fit on the stock Skorpion carb?

[Bill Jurgenson]

No.
It is made to go into the Raptor airbox. The flange is screwed down inside against the front wall and the filter clamps onto the two obvious noses. As you a see, both sides have the same diameter as well. That is because the Raptor does NOT use the same carb as the xtz engine. It has a dual CV carb,

not a register compound type like we have:


The airbox is entirely different too, and does not fit any of the bikes in question.

On the dutch Mono connection site, you can find directions for adapting a K&N car filter for the Skorpion:
http://forum.monoconnection.nl/viewtopic.php?t=908&highlight=honda

For dual Mikunis, there is a K&N dual filter off the shelf:

K&N ref. nº. YA0086

[basser23]

Just to chime in here,the Raptor carbs do work on the Baggi and Skorp,question is though...when the Mikunis
aare avail,the Bst 33's from the Raptor dont give the same results...it is however a cheap alternative as they
are readily available..
Chip

[Wonkmeister]

There are many options available for tuning motors. To be fair most tuners will offer various options when tuning motors or customising aspects of your machine. Many "enthusiasts" will have used a certain method to obtain more horse-power and they would believe this to be the "best" way forward. Although many options would work and indeed offer a substantial power increase it is important to decide what you are using your bike for in the first place. There is absolutely no point in modifying carbs, air-boxes, etc for general road use or weekend fun when you can just do mods like over-bore your motor, gas-flow it, jet it and add pipes. If your going balls out and just want to persue a project to the bitter end and throw shed loads of cash into it then go for it! Just bare in mind that there are thousands of enthusiasts and tuners in the world, and as much as their advice and knowledge may be impressive and productive, it's important to use people that will advise you on YOUR project and not their own! We have had many enthusiasts contact us over the years, as many other reknowned tuners have, regarding modifications they have tried but haven't worked as well as they have expected. I'm not saying by any means that WE are THE company to talk to neither am i doubting certain people on this forum or their kind offer of advice. What i'm merely stating is ascetain exactly what you want to achieve with your machine and stick to it. Then go to a reputable company for advice/tuning/modification. It's all well and good getting advice from enthusiasts and picking up tips but all your really doing is copying some-one else's work that might not actually be what you need. Modifications can be achieved to extremes, it depends on how deep your pockets are. I tend to ask myself this question, what experience does the person i'm asking advice from REALLY have, what record of achievement do they have? Then i make my decisions on what to do and how to go about it, works for me!

In response to all the comments on carbs, Keihin 39mm FS carbs are undoubtedly the best carb you can fit to the XTZ 660 motor. We have tried all kinds of carbs on many types of engines since developing the first Factory Skorpion in 1994. Our own Championship winning Factory Skorpion and the current fastest XTZ powered supermono's run Keihins. They are proven and completly rebuildable. They last for years and years and produce impressive performance data, they are a little more expensive but if you want to plug a decent set of carbs onto your bike and go through all the air intake mods then these are the BEST on the market, tried and tested and used by leading teams throughout the world.

[Bill Jurgenson]

It is true that the Keihin are vastly preferred in the XTZ scene, here, too. The crossers (KTM,Husky, etc) also prefer the Keihin FCR39 or 41. Here in Germany, however, the Ducati tuners by and large prefer the Mikuni. In their opinions, the Mikuni is better made. It is also considerably harder to set up, something I know from experience. To paraphrase one of the Ducati tuners, 'the Keihin is a a tractor carb, crude, but easy to use and set up.'

In the case of the present discussion, tho, there is no real point in discussing the Keihin FCR39, because it is simply too large for anything but full race solutions. The 40, 38 and 36mm Mikunis are also too big.
The German Keihin importer does list a dual FCR 35 for the Raptor, XTZ, and SRX:
http://www.keihin.de/index.php?type=flat_cr&info=preise
The American does not.
The UK distributor lists both Mikuni and Keihin
http://www.allensperformance.co.uk/index.html

as does the Australian distributor
http://www.showandgo.com.au/about.htm?about_bf.html~mainFrame
Like the German, they also list dual CR33, 35, and 37 for the SRX which of course also fit on the XTZ engine, altho I don't know it they fit under the tank of the Skorpion. I have an elder dual CR33 and it does fit with a little good will. For everyday driving, round slide carbs are easier to live with.
The CRs definitely do not fit onto the SZR without considerable modification to the airbox, nor do any of the FCRs or the Mikunis.
Of the flatslides, Mikuni Raptor kits do fit under the tank of the Skorpion and I assume the Keihin Raptor kit does as well; judging form the pictures of it, there should be no problem.

If you are in the UK, Slipstream is THE address. I value Martin's advice highly. In the States, both Galen Miller and Tim Barker have a lot of experience and also racing success with "our" engine. TIm has been a big help in the past for me as well.
Here in Germany, it is not so easy. Steve Topham has quite a bit of experience, at least with heads and carb setups.
As an example of what a "reputable" shop did, I relate (no pics online just now) this: in tuning an SZR for racing, headporting etc.etc. they installed a "performance cam," not a Megacycle, and so-called racing valve springs, not from Kibblewhite. The spring retainers are not heavily recessed like those of Kibblewhite, so the springs are not actually any longer than the stock items. i.e. too short for the valve lift in question. Both exhaust valve outer springs broke and in a matter of a very short time. I know this because a customer of mine bought that SZR.
In another similar case, the lift of the no-name cam was so extreme, that the spring was completely closed, i.e. blocked, and the end of the valve above the retainer broke off, dropping the valve into the cylinder, this time the center intake valve. Not cheap. Definitely new guide and valve, maybe new piston, too, and that would mean renewed honing as well. And a reputable cam as a matter of course.

I disagree however that overboring should be anywhere even near the top of a list of things to do. Gasflowing, sure. Headers, too, of course.
A Carillo is good, but up to 60hp definitely not necessary. Not only I think that. Bernd at Tunebike is the same opinion. My own 59hp street bike with over 80tkm has the OEM conrod which is still going strong on the OEM crank. Even tho it it gets revved to over 8000. Don't get me wrong; if you are seriously going for real power, you will want a Carillo, at least and lots of other expensive goodies, too.
But the OEM carb, is, like any CV carb, just hopelessly sluggish. There is no way around that fact. It behaves like a CV carb is supposed to - who would have thought of that?
The simple change to a good flatslide (or roundslide) of suitable size, i.e. not larger than 34mm, does more than any single measure to improve performance, drivability and fuel economy than any other single measure, and it is non-evasive, does not damage the engine in the least as long as the jetting is proper. Larger headers would be ideal in combination. Buying a good flatslide is not a cheap option however. Larger headers aren't either, unless you happen onto a used Replica system or the Remus Cup system. Headers from the TDM do fit and are suitably larger, but the mating to the back parts you'd have to do yourself.
they are used for the purpose however, are cheap and plentiful.

It seems to me, though, that I wrote all that before. I personally do not advocate touching the engine at all until everything has been done to the chassis that can reasonably be done to it. In particular, mounting better, lighter wheels. Don't even touch the engine until chassis tuning can't be bettered. It is both far cheaper and safer that way.

[Wonkmeister]

I disagree however that overboring should be anywhere even near the top of a list of things to do.

When you think about "average joe" and what they want from a bike, 99.9% of people will mod th engine first as it is the most "obvious" choice to enhance your machines performance. If a customer inquires with us about modifying a motor we always establish what kind of chassis the motor is being fitted to. If we know it's going into a "stock" chassis and we feel the chassis, brakes, etc are not up to the job (which is pretty rare i have to say) then we will advise on upgrades to suit. We have a substantial list of customers with tuned motors fitted to a stock chassis, ok some have opted for slightly better front brakes but nothing major. The standard suspension may be fettled a little but nothing more. To expect a customer to start modding their chassis first would be an insane approach for us, our customers would think we are mental. It would be like saying to some-one lets sort suspension, brakes and wheels out first (that you can test with your stock motor), then you can be sure your bike will be "safe!"-? It just wouldn't happen. Of course i agree that safety is paramount but lets face it, we don't live in a dream or "ideal" world do we!? No matter what advice you can offer tuning customers they are still going to start with the motor, no matter what, and to be quite honest i agree with them. Take a stock R1 and fit a race-kit to it and it would work perfectly fine on a stock chassis, the brakes would be perfectly adequate too. Not so much on an MZ as the stock brakes are pants anyway, they feel like your trying to sky dive with sweet wrapper for a parachute.

I should also add, i never stated where my suggested modifications should come on a "list" or an "order" to do things, that comes down to budget and which options are viable first for the customer. As i said, there's a difference between an enthusiast and some-one that's been doing it since before trees. Approach is different and so is what your expecting from your machine. The highest percentage of bikers i know with tuned motors couldn't care less whats been done to the bike. As long as they notice the power increase and they can go out at the weekend and cane their bikes then that's fine, many don't even know how to change their oil, and that's just fine. I don't judge them by their attitude towards their machine, they just bought a bike for fun, when it breaks they bring it in and we fix it, when they want to throw some money at it, we mod it for them. Same principal as my boiler blowing up, i employ a plumber (albeit my mates dad) to come and fix it, i don't want to be a plumber or care to know all the different ways to fix a leak. At the end of the day you have to look at tuning as a service we provide and not a service whereby we have to turn our customers into engineers or workshop head cases. Many of our customers just want their bikes to go faster and start up on Sunday mornings....they couldn't care less how many turns the rear shock has on the pre-load adjuster or what type of springs are in the head of their machine, what the valve clearances should be, etc, etc. I feel that trying to be a tad too "techy" with people is very arrogant and not called for. If some-one asks then we will answer. We advise on safety, but like they give a toss...they've just added BHP to their motor and that means now they can go and play being Valentino Rossi, at least they are happy and at the end of the day NONE of the thousands of customers we have on our books have killed themselves due to our modifications or our servicing...the numbers speak for themselves.

Every racer i've ever met has a local or "favorite" tuner simply because they are friends or friends of friends. Most use certain people because of cost or reputation, who-ever they use and what-ever the reason i couldn't really care less...as long as they are happy and their bike feels how they want it too that's just fine by me, at the end of the day, it's not what you've got under you or how much it costs...it's what you can do with it that counts, all the money in the world doesn't make you James Toseland...sheer bollocks and pure talent does that!

At Slipstream Tuning we look after our customers, at times things go wrong..that's just the way it is, what counts in the end is our reputation and the fact that for nearly 4 decades my friend, and boss, has been tuning motors successfuly and is reknowned world-wide for his expertise...that's why people trust us! I feel these experts are a dying breed. You don't find many people in this world like Martin Sweet, Stan Stephens, etc. People such as these that have devoted their entire lives to motorcycle racing should be respected, after all they have lived it, and when it comes down to it, they really "DO" know what's best and what works...that's why they do what they do and it's also why they are here today, still Tuning bikes. I've heard lots of bitching and lots of "slagging" off about different tuners, at the end of the day, try them and find out for yourself. If some-one put a chocolate cake down in front of you that you've never had before, would you ask the guy eating a slice what it tastes like and take his word for it or try it yourself?

I use 39mm Keihins on my MZ by the way, and so do 3 of my mates on their Skorpions. Andy Drivers got two Skorps with 39's on and he uses them on the road all year round with no grumbles....just goes to show....what works for some, obviously doesn't work for others!

[basser23]

I would say I have to agree (again) to both sides as far as mods are concerned..
Getting the thing to weigh as little as feasable(ie wheels,freer chain etc.)will
increase the perforamnce from a response standpoint. Further the engine mods
would increase that even further....so the ideal (for me) would be a lighter weight
machine with gobs of usable hp...throughout the rev range...
The weight decrease is worth 5 hp ...if I lose that extra 10 lbs myself,it's got to be worth another 5hp....
As far as FCR's are concerned...they are the "dog's bullocks" in my opinion.
Chip

[Wonkmeister]

Exactly the point Chip me old matey! Personal pref' and all that, your a short-ass anyway Chip, if you lost any more weight you'd be like an ant on a firework!

[basser23]

Not quite Danny Pedroza..yet
Light up the fireworks....whooooo whooo!!!!
U're a trip Wonk!!

[Wonkmeister]

[Bill Jurgenson]

I promised a pic. Here are the broken valve springs:


----------------

Of course you are running FCR39 on your super Baggi; I a running TM38s on my "good" engine, too. Both of those engines are light years away from what was initially being discussed here.

---------------

R6

I would be the very first to say, "if you want to go racing cleaply and dependably, buy an R6."

But what's the point here? This is supposed to be an MZ forum and we - or at least I am primarily referring to the Skorpion.
I don't know very much about the Baggi, apart from the engine. I've ridden several and also test-ridden/dynotested one, but I don't like enduros/sumos and would never use one, much less buy one for myself.

There are no two ways around it: the Grimeca shit on the Skorpion is just that, shit.
The wheels are heavy, crummy and sometimes not even really round. They positively don't like curbs, either. The brakes are downright dangerous.

[Wonkmeister]

Hey Bill, take a deep breathe you old fossil, you'll give yourself a heart attack, this is an "open" forum free for ALL to comment. Not personal, no attacks on you or your "knowledge" at all. You asked "what are we talking about here?"...well....top of the page mate....XT660 WHAT MODS CAN BE DONE? That's the topic of discussion on this thread....ya still with us or you throwing your toys out of your pram again and blowing things outta proportion...hey i like that...BOP-haha-Blown Outta Proportion...i feel a new project coming on...aahh now where was i?....aha...yes...BJ...engine mods....right Bill indeed i do use DA KEIHIN KINGDINGALINGS on my machine...cos they kick ass and are far superior to anything else out there!

Mods...

Paint motor
Don't paint motor!
102mm oversize (686cc) - (WISECO or JE)
105mm oversize (720cc) - (JE)
105mm (88os pin) - Longstroke (760cc) - (JE)
Gas-flow head
Carrillo rod
Taller 1st gear and Lower 5th gear
Close ratio gearbox (Mega money but worth it if you can afford it-wheelie mayhem!)
Carb mods...well....BJ recommends budget so get yourself two coke cans, cut the ends out, shove some elastic bands in there-don't forget the cocktail sticks...VERY important, glue to an old biscuit tin, bash it into shape then clamp it onto your engine and you should be sorted! Otherwise choose from Keihins or...er.....yeh Keihins.
Cam-chain conversion
Stainless bolt kit
Oversize headers and a 2into2 system
Downdraught head can also be used on the SKORPION if you use Andy Drivers bodykit and airbox conversion. Fuel tank goes under seat! Tank becomes airbox.
Change rear swingarm too if you so desire, KR1s swingarms are favorable. Ther's also a very good friend of ours in the states that can help you out with a swingarm and a Titanium axel to fit.
R6 fork conversion...means more wheels available, you can also change swingarm to fit R6 or CBR 600 wheels.
Modified CDI (£90 from Slipstream) Allows engine to rev its nuts off...
If your feeling really flash we could always have a motor made out of glass and a TEFLON piston made with a carbon fibre rod and a cardboard pin, this should help with performace, we could also add some LED's and you could hang around with the local kids and get down in the hood with some disco light fever, maybe even wear the infamous white suit that John Travolta is famous for shakin' his bits in. Really add some style to your Skorpions street cred! You can also run it on cows sperm for extra slick lubrication and a long servicing interval...

OOOOOOOOOOOOOOOR...lets take everything off the motor and shave as much metal as we can off the parts to make it super lightweight and watch it rev to 8000RPM then implode on itself and shit parts out of the end-can...now that sounds like fun!!!!

OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOR...even better still....leave it standard and you won't have to worry about what carbs fit, what mods to do and you know it's going to run for ever and ever...unless you forget to change the oil! Now that's another story...




(NOTE:If you need me to buy you a sense of humour for xmas just drop me a line! )

[MSW]

Stop it! You're killing me!!!



That was hilarious.

BTW, I do have a serious question that might just get this thread back on track. Wonky, a couple of times, you've mentioned "gas flow the head" as a mod. Is that the same as porting the head? If so, what else does that change on the bike? Or can you gas flow the head without having to change the carb/intake or exhaust positions?

I know that's probably a dumb n00b question, but what's better than a dumb n00b question to reel the discussion back in?