What makes the xs650 engine so special?

JHollman

XS650 Member
Messages
5
Reaction score
0
Points
1
Location
salisbury
Hi, first post here, newbie so bare with, thanks!

I am about to start planning my first build and then over the year start building, i am still undecided if that will be from the floor up or strip/restore a runner.

everywhere I search about first projects, points to a xs650, I have read about the engine's simplicity (in the grand scheme of things) and the frames ease of modification but the output of the engine, how does it stand up to others, do you really need bigger engines or is a 650cc sufficient. I will be commuting around town and also long distances from time to time. for instance my partner, she has a Triumph Bonnie I think 8-900 cc (off the top of my head. her brother a Yam drag 1,100 and father same but 1,300.

I personally want that low rev tone/feel and the high torque of the line, and from what I have read the xs650 fits the bill (HDesque cough*) and is one of the most versatile engines?

On a cost angle, this seems the best option, if I had the money I am not going to lie I would work with a triumph making a custom out of British heritage but I don't have the money and being my first build I am slightly put of.

Just to note, I shall be designing etc for a long period of time so this is me feeling the water before I jump in one direction.
 
When I decided to build something a few years ago I was going to use an XR650L engine actually. I then stumbled on XS650 probably like you did. I asked hte same thing in my head. So I started looking at builds and then looking at pother non XS650 builds. It became clear to me at least. Looking at it it looks an awful lot like the Triumph and BSA engines so it has that vintage look, is air cooled, is simple and bullet proof. Lots of engines are simple and bullet proof but who wants an inline 4 in a Bobber. Who wants a CB550 or 650 hanging out over the sides of a frame.

Aside from that many used it for flat track racing and what not long before all the bobbers so there was some pedigree too. All the better.

Looks, performance, that spawned the popularity and that in turn spawned all the options and support. That's my opinion on why.Japanese reliable engine that looks nostalgic.

Best of luck on the build!
 
Well, one of the biggest reasons why it's special is that it is almost a 50 year old design and you can still get parts for it. Try building a bobber around a Tempter 650 motor and see if parts are as readily available (although I DO like Tempters, ummm....GR650's....). It is also a good looking motor, with bits that shine, with those nice inspection covers around the head giving it a look of a crown. It is a durable piece, with a beefy roller bearing bottom end. Even the cams ride in ball bearings. Simple to fix. Upgrades galore. The CB500 twin also checks most of these boxes, but I doubt parts availability is nearly as good (could be wrong...) KZ 750 motor is probably a bit stronger, but it is a square, industrial looking motor that looks like it should be powering a wood chipper or something. It is a bit complex and heavy for what it is as well, and starter clutches have a way of failing in a manner that can be downright dangerous.The Tempter also looks kind of Japananonymous, and it has no kick starter either.

I don't know if the power is there to keep up with your riding partners bikes if they decide to gas it and go, but it is a satisfying ride at moderate speeds. It has a really nice sound with decent pipes.
 
Last edited:
A 650 is a great around town engine and can be pressed into highway duty but it feels strained in stock form at anything much above 60-65MPH There's a reason 650-750 twins have been so popular for so long. Honda is building a whole series of bikes around their 700 parallel twin engines now. Another "current" engine is the Kawi 500-650 twins that appear in a bunch of guises.
XS650
LOTS were built somewhere around 1/2 a million. Therefore easy and cheap to find.
simple
reliable if not pushed TOO hard.
Very well supported with aftermarket, perhaps the best supported MC engine in the world.
I did three 100 mile plus runs on the resto mod a few weekends ago and my 62 year old body was ready to get off for a bit. I keep thinking I could set up an XS for a long distance backroads ride with camping gear, maybe will. The terrain is England is a completely different arena than arround here. Locally there are lots of fun B and C roads. Heading Northwest from here a state line every 3 to 500 miles is about the only thing of note till western Montana, 1600 miles away, Usually done on freeways with about a 75MPH traffic speed, That's a different kind of riding.
This forum in no small part is a good reason to decide on the XS650 motor!
 
Last edited:
Hi, first post here, newbie so bare with, thanks!
I am about to start planning my first build and then over the year start building, i am still undecided if that will be from the floor up or strip/restore a runner.
everywhere I search about first projects, points to a xs650, I have read about the engine's simplicity (in the grand scheme of things) and the frames ease of modification but the output of the engine, how does it stand up to others, do you really need bigger engines or is a 650cc sufficient. I will be commuting around town and also long distances from time to time. for instance my partner, she has a Triumph Bonnie I think 8-900 cc (off the top of my head. her brother a Yam drag 1,100 and father same but 1,300.
I personally want that low rev tone/feel and the high torque of the line, and from what I have read the xs650 fits the bill (HDesque cough*) and is one of the most versatile engines?
On a cost angle, this seems the best option, if I had the money I am not going to lie I would work with a triumph making a custom out of British heritage but I don't have the money and being my first build I am slightly put of.
Just to note, I shall be designing etc for a long period of time so this is me feeling the water before I jump in one direction.

Hi JHollman and welcome,
um, that's Salisbury UK, not one of the others?
What's special about the XS650 engine? It's built like a brick shithouse and it's simple.
Not as simple as a J.A.P side-valve single but as simple as a single OHC vertical twin can be made.
Even if the engine has to be taken out of the frame to remove the cylinder head.
It's said that there's no such thing as too much horsepower but the XS650's real world useable ~45 HP
will be enough to get you a speeding ticket anywhere even if it won't let you keep up to your partner's dad's 1,300 cc Yamaha.
What I'd advise is you find a nice XS650 runner and ride it for a month or so to see if you like it before starting your build.
If you find it's not the bike for you it'll sell on a lot easier as a complete machine than it would as an abandoned project.
 
Gary said it--half a million XS650s made, popular back in the day because they were the lowest dollar per cc. available (short of WWII surplus military Hardly 45 c.i. flat heads that were going for $50 still in the crate). But with all the fashion followers and me too's buying them up and tearing them up, XS650s will be just as rare as the old WM Hardlies in a few years. The HDs couldn't be given away and all but a few survivors got fed into the crusher, so those are high dollar collectors' items now. The new generation of buyer is doing the same job of herd thinning for the XS650.
 
Last edited:
Gary said it--half a million XS650s made, popular back in the day because they were the lowest dollar per cc. available (short of WWII surplus military Hardly 45 c.i. flat heads that were going for $50 still in the crate). But with all the fashion followers and me too's buying them up and tearing them up, XS650s will be just as rare as the old WM Hardlies in a few years. The HDs couldn't be given away and all but a few survivors got fed into the crusher, so those are high dollar collectors' items now. The new generation of buyer is doing the same job of herd thinning for the XS650.
Takes a grumpy old man to know one.
 
Yup and I think that is why so many of us lament the chopping that is going on. There are plenty of other less "good" bikes out of which one could make a chopper - but doing it to a really nice XS650 just somehow seems...wrong.

JMO - don't wish to offend anyone.
 
Special for maybe four reasons.....................engine simplicity, engine look, engine torque, engine toughness.
It does not have high horsepower, so don't plan to run with 900+ cc bikes, when they race along at 130 to 140 kms/hr.
100 to 110 kms/hr can run all day long.

I say let the choppers keep chopping..........................it just makes my bike more rare, and worth more every day.
 
Hands down, the XS 650 is the best "B" roads bike. Big enough to get into trouble speedwise, if set up right comfortable enough to spend all day on, properly maintined, will last just short of forever. Handles decently. Light enough to go around town but heavy enough for highway speeds. It's not the best highway/touring bike. 750 and up is better IMO. This bike is so adaptable to do just about any style of rideing or customizing.
 
I've always been into choppers/bobbers and my last build was a '69 CB 750. It was great for power and top end but the darn motor was so wide it made my hips hurt from riding with my legs spread so wide. When I did this bike I wanted something with power and a narrower top end. I remembered years ago my good buddy had an XS and he loved it so I looked for a project 650 to build. It was a good choice.
 
Well that was not the first impression I was looking for, but I understand that people are passionate about the xs650. I would like to clarify that I am 90% going to build this bit by bit from spare parts and If I do''chop'' then it will only be the rear end and would not take a perfectly good bike but something I need to work on. That is my choice and the whole reason for me building/chopping is to get a personalised bike and to get a feel for it.

Everything apart from the heritage (yes I know, but I have a passion for my girlfriend's bonnie and dream of building a bike around one while keeping colours etc true) but my budget is not in that area and for now this is my first build and I am sure of many.

I live in the countryside (Salisbury UK) where it is mostly b roads with a few a roads (dual carriage ways) etc - no motorways unless I will be heading anywhere like London etc. I want an engine where I can feel and hear it and a bike that will handle amazingly. The xs650 seems and has been proved here to fit the bill. My girlfriend keeps questioning why I am building around a 650cc and not going bigger which I would argue all the points in this thread but it does put doubts in my mind. Then again my budget does not stretch to a larger engine and I don't actually like the look of the bigger v-twins. the xs650 basically has a similar look to the bonnie engine and I like that.

Thanks for all your advice, I shall be slowly planning this and will put a thread together once I get the plans and then ball rolling. I also hope that even though I shall not be restoring to an original that people will be willing to lend a hand when I need advice, that's the reason I come here :)
 
The following may sound harsh, but please understand that I mean it kindly. If you want your bike to "handle amazingly," you need to learn enough about suspension to realize that chopping "only the rear end" (with extended swingarm, elimination of swingarm for hard tail conversion, etc.) is going to have seriously bad consequences. Handling of the XS650 is a long way from "amazing." It can be made decent to good if you invest serious work and serious money in the suspension. If you let your imagination get ahead of your knowledge, you'll wind up with a pile of parts to sell at a loss, and the market for unfinished projects is already well glutted.
 
Special for maybe four reasons.....................engine simplicity, engine look, engine torque, engine toughness.
It does not have high horsepower, so don't plan to run with 900+ cc bikes, when they race along at 130 to 140 kms/hr.
100 to 110 kms/hr can run all day long.

I say let the choppers keep chopping..........................it just makes my bike more rare, and worth more every day.
The following may sound harsh, but please understand that I mean it kindly. If you want your bike to "handle amazingly," you need to learn enough about suspension to realize that chopping "only the rear end" (with extended swingarm, elimination of swingarm for hard tail conversion, etc.) is going to have seriously bad consequences. Handling of the XS650 is a long way from "amazing." It can be made decent to good if you invest serious work and serious money in the suspension. If you let your imagination get ahead of your knowledge, you'll wind up with a pile of parts to sell at a loss, and the market for unfinished projects is already well glutted.

Apologies, I let my definitions run ahead of me, by handling, I did mean turning radius (thus why I am not interested in these massive Yamaha cruisers etc), whether that still applies to your point, I do not know...and this is a first project and one I am fully aware im going in blindly with the plan of learning as I go along (well before I start)
 
The following may sound harsh, but please understand that I mean it kindly. If you want your bike to "handle amazingly," you need to learn enough about suspension to realize that chopping "only the rear end" (with extended swingarm, elimination of swingarm for hard tail conversion, etc.) is going to have seriously bad consequences. Handling of the XS650 is a long way from "amazing." It can be made decent to good if you invest serious work and serious money in the suspension. If you let your imagination get ahead of your knowledge, you'll wind up with a pile of parts to sell at a loss, and the market for unfinished projects is already well glutted.

And I always see things through and do not intend to stop here, I like challenges and anything that becomes challenging and near impossible at times (nothing is) has always spurred me on to finish it even if that means going to someone else to learn etc
 
Well that was not the first impression I was looking for, but I understand that people are passionate about the xs650. I would like to clarify that I am 90% going to build this bit by bit from spare parts and If I do''chop'' then it will only be the rear end and would not take a perfectly good bike but something I need to work on. That is my choice and the whole reason for me building/chopping is to get a personalised bike and to get a feel for it.

Everything apart from the heritage (yes I know, but I have a passion for my girlfriend's bonnie and dream of building a bike around one while keeping colours etc true) but my budget is not in that area and for now this is my first build and I am sure of many.

I live in the countryside (Salisbury UK) where it is mostly b roads with a few a roads (dual carriage ways) etc - no motorways unless I will be heading anywhere like London etc. I want an engine where I can feel and hear it and a bike that will handle amazingly. The xs650 seems and has been proved here to fit the bill. My girlfriend keeps questioning why I am building around a 650cc and not going bigger which I would argue all the points in this thread but it does put doubts in my mind. Then again my budget does not stretch to a larger engine and I don't actually like the look of the bigger v-twins. the xs650 basically has a similar look to the bonnie engine and I like that.

Thanks for all your advice, I shall be slowly planning this and will put a thread together once I get the plans and then ball rolling. I also hope that even though I shall not be restoring to an original that people will be willing to lend a hand when I need advice, that's the reason I come here :)
 
Hell, all you gotta do is look at it. The most beautifully arranged engine ever produced. I bought my 1st, a 73, based on looks alone. (Ann-Margret symptom). And as good and reliable as they are, I continued to buy more later. The engine's appearance is the gift that keeps on giving. Never get tired of looking at them.
 
Back
Top