I was looking through the new Screamin' Eagle catalogue, and noticed something I haden't seen in there before...an engine kit to build a neaarly complete XR 750 enigine! I wonder what the reloiabilty is like, or if you can get a big-bore kit for it.

Anyways...it'd be sweet in a sportster, or even a race-inspred bobber project...

I noticed that too when I checked out the online catalogue. That damn engine probably costs more than my whole bike did.

I wonder how much power a person can expect out of something like that.

That's a good question...I would imagine that those motors are pretty potent or else racers would be using one of the other many 750cc engines out there. I would venture to guess that witht he right work done you could expect 80hp or better.

I'm sure it's a $5000+ engine (only becase it doesn't come assembled, and it does require head work.) Still, it's a bad-ass looking unit.

I remember back in the 1970's when the XR 750 H-D's ruled the race track. Nothing could touch them on the dirt ovals and it was while before Yamaha over took them on the road race circuit. I think I recall reading in the Enthusiast or something back then that Harley even had a street prototype back then as well.

I remember back in the 1970's when the XR 750 H-D's ruled the race track. Nothing could touch them on the dirt ovals and it was while before Yamaha over took them on the road race circuit. I think I recall reading in the Enthusiast or something back then that Harley even had a street prototype back then as well.


Yeah Fox..

I can recall seeing some pics in some of my mate Bruces old mags.... the closest they got was when they made the XR1000 for the street as a limited run...would luv one...

twin exhausts, twin inlets.... and the heads were done by Jerry Branch from memory...

Went like stink :clap

They were the quickest stock HD for many years untill just recently

Here's some specs of the XR1000...not bad considering it was '83

Claimed hp 70 hp @ 5600 rpm
Claimed torque 78 ft-lb @ 4400 rpm
Standing 1/4 mile 12.8 sec @ 101.23 mph


Just as a matter of interest... these engines (XR1000) were the ones Eric used in his origional Buells

I'm a huge fan of flattrack racing and really want to get into vintage flattrack racing soon. I think the race tuned XR750's are putting out more like 90+ hp. I'm pretty sure that figure is more accurate. I hear they are a real bear for the mechanics and require quite a bit of wrenching to keep them in top tune producing that kind of horsepower. You have to figure, that's somewhere near what the Buell 1200 engines are producing, but the XR750 race bikes probably weigh under 300 lbs giving them a huge hP to weight ratio over something like the Buell. I owned a 1996 Buell S1 (the original sport model and the best in my opinion as it was a very stripped down design with small seat etc., really true to the original concept.) It ran well! I couldn't imagine shaving 100+ pounds off of it, that's what a race tuned XR750 would feel like. The power curve on the XR's I'm sure has most of it's hp coming in at the higher RPM's unlike the S1's broad nearly flat power curve and somewhat low red line.

T

Well the 750 would run more RPMs less CCs would me less rotating mass. If I am not mistaken the XR-1000 had 1000 CC iron sportster jugs and pistons witht he XR head. Plus the duall Mikunis. You could probably do the same with a newer engine. More CCs would mean more streetable power without having lean on the engine so hard like in the race aplication.

Yeah I rember when Jay Springsteen and Cal Rayburn were burning up the tracks with them. What sticks out in my mind is what comparatively tiny rear sprockets they ran. Must have had a ton of HP and torque.

:D Hey Guys,

I think H-D racing dropped building complete XRs years back. In the old days you had to homoligate about 50 bikes for AMA comp. There's a famous picture of a load on new XRs sitting waiting for homligation.

Now you purchase an engine, stuff it in one of the aftermarket single shock frames with all the go fast goodies, and go racing. Don't have a clue what a competitive national level bike costs now. Well over $25 grand.

A few years back, I started training on a vintage Yamaha TT500 for vintage flat track. Divorce side tracked that. Still got a new Ken Maley steel shoe in my gear bag! If they ever re-open the local short track, I'm taking my Honda CRF150 out for a slide.

Ride the "blue groove!" :clap