Does anyone have a line on XR 1000 aftermarket pistons? I'm doing a performance rebuild, and need 10:1 - any good reputable brand will do. I just ordered a set of E grinds, and the heads are getting done next month, so the slugs are only the missing piece.

Arias use to make XR pistons on a regular basis for sale. They now only make them by custom order. (they custom make pistons for just about anything that uses a piston) Give them a call.

I purchased a set from Rivera Engineering when they use to stock them. I think they only have the rings now in stock. Rivera still lists in their catalog the Andrews cams for the XR-1000 by the way.

Talked to them right after I posted this, should have a set getting done in a few weeks. Just curious, do you know what your bike is putting out in terms of power? Ours are going to have a lot of the same mods, except that I'm running the dual Supertrapp set-up, and will have some head porting done.

I don't know how much research you've done on that particular engine, but they aren't known for big HP numbers. The valves are 750 sized and don't flow well enough to feed a 1000cc engine.

We tried running one in the 1000cc P/PP (Production) class at Bonneville. It couldn't go over 130 MPH. An 883 punched to 1000cc went 135 or so in the same class.

Aaron at NRHS knows HUGE amounts about making HP from these engines. He used one in a Buell RR1000 and did rather well.

My guess is you'll be lucky to get over 70 HP from an XR1000. They're cool bikes, but not powerhouses.

They can make good horsepower if set up right. They make about 70 HP stock. I base that on the fact that they could run a 12.9 in the quarter mile. You ain't going to run no 12.9 with less than 70 hp. With the E cams, pipes, pistons ect you can probally get almost 90.

Aaron was getting almost 150 HP out of his. His was tweaked to the max and, the guy that is doing my lower end right now has a one time speed record holder XR he runs at Bonniville at well over 150 MPH.

Rich Products, before they went into the header biz, used to have a machine shop and ran an XR at the drags. It ran low 10's at the strip. Which probally equals about 110-130 HP. They used to sell a performance package for the XR's that had a cams, Arias 10-1 pistons, thunderheader type exhaust (without the sound absorbing material inside, a true reverse cone megaphone) and an ignition . Other than that, all else was stock XR, carbs, heads ect. It was the same parts they used in their drag XR.

So, these motors can make some serious HP. If they are setup right and tuned right. The weak link is the lower end. Can't take the beating without some serious mods. Rich Products used to modify the lower ends (HD crank pins, reinforce the case bearing, balancing, windage trays) and Yankee Enginulity has the ultimate mod for the XR lower ends. (same things except the replace the case bearing with a whole different type of bearing and modify an early style S&S crank assy. to work with the new bearing) This is the only way to go if you plan on making 100+ HP and having it stay together. Aaron had the same mod done to his lower end.

Rich Products did my original set up and that motor was putting out close to 100HP. It was just as fast as my 1250 is now. But, now I want the big HP.:frownthre

These bikes are killing me.:laugh

By following Don Tilley's road racing setup, I got 106HP from an '83 XR1000. Not a radical setup and pretty streetable. Pump gas will not work. The valve sizes were stock. The 1000 has a bigger intake than the 750. The ports are very efficient,especially if worked a little. The individual runners are a whole different game than an XL. A 1200 has a 20% displacement advantage if no one has noticed. BTW,Lucifer's hammer regularly exceeded 150mph.