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MT07 power - and that of the competition


faffi

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weakest link is the "nut" between the handlebar controls and the foot controls 😛... 

2015 fz-07- Hordpower Edition...2015 fj-09- 120whp- Graves Exhaust w/Woolich Race Kit- tuned by 2WDW
 

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According to an ex-vendor of this forum (of air box fame), the  Fz-07 has such mild cams that he was surprised that it made the power that it does. An engine in this mild state of tune with frequent oil changes should be a real high mileage engine...ridden sanely and without any inherent design flaws.

 

The auto cam chain tensioner could be a weak point for sustained high rpm use such as racing but that's just my speculation and easily fixed with a manual tensioner so probably no big deal.

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7 hours ago, markstertt said:

The auto cam chain tensioner could be a weak point for sustained high rpm use 

How so? Assuming the auto isn't a piece of crap (looking at you Yamaha on the Fx09) you can't adjust the manual until you come back into the pits and go thru the process whereas the auto can ratchet on it's own mid-lap.

Not that tensioners need to adjust very often or there is something very amiss in the engine.

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Note Mr pattonme ...SIR...I referred specifically to the power of the 07. The very nice light short pistons  are not gonna be the initial RPM limit on this little black duck ( in my case a little white duck). Be willing to bet with this stroke they are good for 12000. The inlets and exhaust ports seem pretty nice volume/ID as well. I reckon you could pop a cam of more spritlieness ( I worked in IT. I too can invent words) and only have to mod the spark/EFI curves and the 07 would sing a fine soprano song ( Might even say it could become a lieder amongst others. Though you would probably have to wear a Schubert helmet to appreciate it).

Faffi one of the things that the reflash does is raise/remove the speed and rev limiter as desired. Valve springs could be a problem with the modern motor manufacturers using the crappiest springs they can get away with.

Go forth and modify my son...go forth and modify...

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6 hours ago, gregjet said:

 

Faffi one of the things that the reflash does is raise/remove the speed and rev limiter as desired. 

I know, I was speaking in general terms. And properly designed, a limiter will always cut in just before the engine is destroyed - even after a reflash and engine upgrades :) 

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6 hours ago, pattonme said:

Assuming the auto isn't a piece of crap (looking at you Yamaha on the Fx09) you can't adjust the manual until you come back into the pits and go thru the process whereas the auto can ratchet on it's own mid-lap.

Not that tensioners need to adjust very often or there is something very amiss in the engine.

 

I am no eggspert, but my experience tells me that automatic cam chain adjusters are poor, but better than owners not maintaining their bikes. An automatic tensioner will place a constant strain on the chain that over time will cause more rapid wear of said chain. A manual tensioner is, provided correct adjustment, just sitting there with a mild static pressure. Typically, for normal road use, you can ride at least 10,000 miles between adjustments, often double that or more. Another benefit is that they cannot back out, again provided properly locked in position, whereas automatic tensioners often fail. Kawasaki have a long history of failed tensioners back in the late 70s and well into the 80s. Finally, most automatic tensioners lack the required range of adjustment - both because the chain stretches faster and due to their inherent design - to keep the cam chain tensioned until its worn out. Read about the CX500, LS650 and VN1500, for instance.

 

The automatic cam chain tensioner today is not, in most engines, bad enough that I would consider replacing it with a manual version, because I only ride on the streets and barely ever see the redline. But for racing, I would never consider anything but a manual tensioner. YMMV.

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9 hours ago, gregjet said:

I reckon you could pop a cam of more spritlieness ( I worked in IT. I too can invent words) and only have to mod the spark/EFI curves and the 07 would sing a fine soprano song

Hord has a nice chart showing improvement gained from head porting and aftermarket cam versus stock engine internals (both setups use aftermarket exhaust, PCV tune and his airbox):

 

https://www.hordpower.com/gallery3/index.php/Dyno-Charts/Yamaha-FZ-07/FZ-07SB

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14 hours ago, pattonme said:

so a nice cam and some Kibble White springs and the time to do the head work. $500? 

Man I wish, I'd do it in a heart beat for $500 and throw in the 12.5-1 cr pistons at the same time.

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17 hours ago, pattonme said:

How so? Assuming the auto isn't a piece of crap (looking at you Yamaha on the Fx09) you can't adjust the manual until you come back into the pits and go thru the process whereas the auto can ratchet on it's own mid-lap.

Not that tensioners need to adjust very often or there is something very amiss in the engine.

An auto tensioner is just a weak link in the chain of possible components that 'could fail' on a race bike with possibly catastrophic and expensive consequences...were I building a racer, I wouldn't even think twice about installing a manual tensioner. For about $80, just cheap insurance. My well flogged DRZ has had a manual tensioner for years and I usually adjust it once a year at the start of my riding season but I can't say it's ever really needed adjusting. I do know that it will never fail on me mid ride whilst out in the middle of nowhere.

 

I'd be curious to know if any of the motogp, motoamerica or superbike type racers use an auto tensioner or even if any of the supercross/motocross guys retain an auto tensioner...anybody know?

 

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7 hours ago, stickshift said:

Hord has a nice chart showing improvement gained from head porting and aftermarket cam versus stock engine internals (both setups use aftermarket exhaust, PCV tune and his airbox):

 

https://www.hordpower.com/gallery3/index.php/Dyno-Charts/Yamaha-FZ-07/FZ-07SB

I believe in this case that Hord only replaced the intake cam along with porting, compression etc....and installed a manual cam chain tensioner.

 

As far as the original post of FZ-07 vs. the competitors? Well, that new KTM 799cc vertical twin is going to be a real FZ-07 killer but at about 2X the price. I'm really looking forward to seeing the Adventure version of this KTM. I just hope the Yamaha T-7 is the bike I'm hoping it can be, I still like the power and frugality of the little Yamaha engine.

 

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Well if he replaced the cams, the power profile looks like it was a bit more lift rather than played with the duration. I was under the impression ( perhaps falsely) that the 07 lift was pretty close to the piston crowns stock so if he did get extra lift it wouldn't be much.

I REALLY do need to get some time to work on my 07 and degree that cam.

 

Go forth and modify my son...go forth and modify...

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Actually he has a chart of where he says he did cams. It is the 13th post down ( not the one before).

It shows the peak HP moved up ( rpm wise) a fair bit as well as increased power at the original peak. Pretty much shows thta the engine really is ripe for camming. It IS possible that it is just better flow but the raised PEAK seems to indicate longer duration.

Go forth and modify my son...go forth and modify...

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22 hours ago, gregjet said:

Well if he replaced the cams, the power profile looks like it was a bit more lift rather than played with the duration. I was under the impression ( perhaps falsely) that the 07 lift was pretty close to the piston crowns stock so if he did get extra lift it wouldn't be much.

I REALLY do need to get some time to work on my 07 and degree that cam.

 

Perhaps the high comp. pistons have deeper pockets? I understand the bump in compression will restore the low/midrange lost due to an increase in duration so perhaps the combo is exactly what this little engine likes, a little more lift, duration and some compression, nothing extreme. It would be interesting to know the specs on the cam Mr. Hord installed. I think if I could do only one engine mod (internally) I would like to install the 12.5-1 cr pistons for the midrange and fuel efficiency aspect...esp. when able to still use 87 oct. with Hordpowers map/flash.

 

 

 

 

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