Yamaha XS850 for a big guy?

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DiabloGrande · Mon Jan 02, 2006 2:21 pm

Hi,

There's a 1980 Yamaha XS850 being advertised in my local classifieds and I'm considering heading over to look at it, but first I want to make sure it would fit me. I'm 6'5" and 255 pounds with a 36" inseam. Am I too big to ride it?

jmillheiser · Mon Jan 02, 2006 6:50 pm

Nah the bike should fit perfectly fine. UJMs are great because they will fit a wide array of riders.

Might be a tad too much power for a first bike though. Not sure how much power an XS850 pushes.

Also make sure the bike is in good shape. Some of those old bikes can be hard to find parts for.

flynrider · #3 Unread post by **flynrider** » Mon Jan 02, 2006 7:59 pm

I think he should be OK witht he power. I used to ride and dyno the old Yamaha triples and the 850 only puts out just over 60 hp at the rear wheel (could've been more without those goofy Hitachi carbs). The factory claimed 75-79 horses at the crank, but judging from the dyno results on several examples, they were being wildly optimistic.

That should be just fine for a large rider. It's also tuned to spread the power quite evenly across the power band and isn't remotely twitchy. I used to remark to my buddy that his inline triple rode more like a twin than a four banger. Power delivery is a nice, steady pull from 3500 rpm to redline.

There are several good groups dedicated to the Yamaha triples and their quirks (like the exploding second gear). It would be a good idea to google around and find out about the bikes quirks before you buy. Here's one to get you started :

http://www.yamaha-triples.org/main.asp?mainheadingid=0

jmillheiser · Mon Jan 02, 2006 8:05 pm

wow that XS is pretty tame for an 850. I was thinking it was more akin to the GS850 which has closer to 100hp iirc.

yeah that XS850 should be fine for a first bike.

Weird? It only has 10hp over my CX500 which is rated at 50hp (and from what ive heard its an honest 50hp)

flynrider · #5 Unread post by **flynrider** » Mon Jan 02, 2006 8:34 pm

I don't have any dyno notes for the normal CX500, but generally speaking, you can take the manufacturers' horsepower claims from the 70s and 80s era and reduce it by roughly 10% to arrive at the horsepower produced at the rear wheel. The mfgrs. used to claim that their horsepower spec was from the crankshaft and didn't include any final drive loss, but I think that's not the whole story. Back then, the rules for horsepower claims were not as well established as they are these days.

BTW - I did find a run for an '82 CX500 turbo. Factory claimed 82 hp, we got 70 at the rear wheel.

Working a dyno back in the UJM days was a very enlightening experience

DiabloGrande · Tue Jan 03, 2006 3:10 am

Thanks a lot, guys. That's great to hear.

The seller's asking $800. Assuming that's a fair, honest price, does that mean the bike is probably in good shape? My dad knows more about mechanics than I do, so I'll probably have him come over with me to check it out.

Money's tight for me right now and all I really want is a simple, no-frills bike that'll let me hone my basic skills (I passed the MSF course but still need a LOT of practice before I'll be safe out in traffic) and provide transportation once I've gotten the practice.

It's also good to know the throttle is steady and predictable, not twitchy. That's exactly the kind of thing I'm looking for.

DiabloGrande · Tue Jan 03, 2006 8:45 am

Okay, I just talked to him on the phone and he says the only problem with it is that there's rust in the tank. Is that an easy problem to take care of?

#8 Unread post by **9000white** » Tue Jan 03, 2006 1:07 pm

depends on how much rust in tank and if it has got in carburetors which will have to be cleaned out if it has.if it is only surface rust inside tank yamaha makes a 2 part rust remover for about $14.00 that works well.