Buyers Beware

[Jack]

There's a gentleman on E bay offering a XS head complete with porting and unless you have money to throw away,steer away,cuz you'll get absolutely zip for performance. His #s fall short in comparison to a stock head and that alone is a cause for red flags. His porting skills of the XS ports are in desperate need of someone who does know what the hell their doing in gaining the most from these badly cast and choked up ports.

 

[weekendrider]

Thanks for the heads up.

 

[Jack]

He's not the only one out there offering porting services with people getting nothing of value for their money. It took me awhile to learn the in's and out's of working the ports but at least my first attempts saw big improvements through the whole lift curve. I'm through posting info on porting.

 

[rahndo]

There's a gentleman on E bay offering a XS head complete with porting and unless you have money to throw away,steer away,cuz you'll get absolutely zip for performance. His #s fall short in comparison to a stock head and that alone is a cause for red flags. His porting skills of the XS ports are in desperate need of someone who does know what the hell their doing in gaining the most from these badly cast and choked up ports.

The link to his page, so we can avoid....

 

[TwoManyXS1Bs]

If this is it, then, yeah, that's not a port job.

Item: YAMAHA XS650 PORTED & POLISHED CYLINDER HEAD W/ 1MM OVERSIZE INTAKE VALVES

URL: http://pages.ebay.com/motors/link/?nav=item.view&id=231478997087&alt=web

Alt URL: http://www.ebay.com/itm/YAMAHA-XS65...AD-W-1MM-OVERSIZE-INTAKE-VALVES-/231478997087

 

[rahndo]

If this is it, then, yeah, that's not a port job.

Item: YAMAHA XS650 PORTED & POLISHED CYLINDER HEAD W/ 1MM OVERSIZE INTAKE VALVES

URL: http://pages.ebay.com/motors/link/?nav=item.view&id=231478997087&alt=web

Alt URL: http://www.ebay.com/itm/YAMAHA-XS65...AD-W-1MM-OVERSIZE-INTAKE-VALVES-/231478997087

Doesnt make any claims as to performance.

 

[Jack]

Here you go. You've got to read the captions below the listing. He say's his ported head has been flowed against other racing heads,including D-Shaped. I don't recall ever sending him one of my D-Shaped heads for a flow comparison and one that would of undoubtedly given him a flow stroke Look at his #s guy's ,when properly ported the XS head should see a positive gain bow effect in the flow curve as soon as that valve lifts from the seat to max lift with a stock combustion chamber. With ample material in the ports and stock valves,a stock intake from my experiences should see on average a 15% gain and the exhaust a 25% gain,which can even shoot higher to over a 90% flow ratio,that's how good that exhaust port can get for bragging rights or bolted to a long rod motor. So look again at his #'s, porting of the ports and ask yourself, would I gain any reasonable power with his ported head.

http://www.ebay.com/itm/YAMAHA-XS65...VES-/231478997087?hash=item35e539305f&vxp=mtr

 

[Jack]

Doesnt make any claims as to performance.

A stock valve would over shadow his 1mm oversize valve up to where his drops off. His oversized valve is a band aid for what wasn't achievable with a stock valve size. There are alot of individuals who aren't up to the task of porting their own heads either by intimidation of screwing up the ports or lack of tooling,this is nothing but a wake up call to be alert of who your dealing with.

 

[chizler62]

I agree with @rahndo seller doesn't really make any performance claims vs anyones. He states That he compared them and then says "low lift numbers have been greatly improved" assume thats the 1mm valve talking.
You could question that hes referencing against other heads, but the graph clears that up.
Then admits it falls short saying "head was not designed for racing"
I'm sure it is what it is.

@Jack you've never sent me a "D-shaped intake port" head. But, one has been on my SF-600e

I will say....those exhaust port don't look so finished. Ugly as my ex-wife.

I ran the math once, for my own bike, and found ports don't really need actual meterial removed. Infact thats why I put that D-shaped head on the Superflow. It didn't make sense.

Posted via Mobile

 

[Jack]

I agree with @rahndo seller doesn't really make any performance claims vs anyones. He states That he compared them and then says "low lift numbers have been greatly improved" assume thats the 1mm valve talking.
You could question that hes referencing against other heads, but the graph clears that up.
Then admits it falls short saying "head was not designed for racing"
I'm sure it is what it is.

@Jack you've never sent me a "D-shaped intake port" head. But, one has been on my SF-600e

I will say....those exhaust port don't look so finished. Ugly as my ex-wife.

I ran the math once, for my own bike, and found ports don't really need actual meterial removed. Infact thats why I put that D-shaped head on the Superflow. It didn't make sense.

Posted via Mobile

Now I'm lost Do I know you? D Shaping the intake ports increasing the port volume opening up the corners of the port leading up to the short turn and then you go back in the ports raising the floor,rebuilding the walls and when completed you'll have a port with smaller port volume that biases max flow down to around .400 lift peaking out at around.430 with a 5cfm increase all with a smaller port volume and smaller cross sectional area that a stock port could never achieve. I worked on this port for 2+ years with the aid of old friend who's been porting heads for some 30 years and I know what it'll do on a flow bench and on a actual motor. You can crunch all those theoretical #s all day, you have to completely restructure the entire port to get it right