'82 XS650 questions from a Suzuki rider


XS650 New Member
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Dayton, Ohio
Hi everyone:

I'm Brendon, and I'm an '82 Suzuki GS650 owner. My best friend, who, for some bizarre reason, hasn't created a user name on this forum yet, is the owner of a 1982 Yammie XS650. It's an inline twin.

He's been experiencing running problems with this bike....which was sold to him last month as "not running, but some TLC ought to straighten out the problems.

Further inspection leads me to think that, based on my GS experience, this bike had dirty, or mis-synced carbs, valve adjustment problems, or both.

I've determined that the bike has Mikuni BS-CV carburetors. However, (because I have a plethora of BS-32mm. carb parts) it seems unlikely that my buddy's twin has the same Cv carbs as my in-line 4. I'm going to guess that the internal diameter for the XS is either 34mm or 36mm (or, perhaps, larger).

First question...does anyone out there in XS land know the inside throat diameter of the coveted Mikuni for an '82 XS650 twin?

Once I know what the size Mikuni parts I am searching for (and, if any of you Yamaha wizards know what carb parts might be compatible between a CV32mm to the larger sizes :shrug:) I can begin showing him what he can buy.

Second question...Does the XS experience the same kind of intake boot o-ring problems the Suzuki GS does? Briefly, once the intake boot o-ring becomes old and brittle, it cracks, allowing unregulated air into the cylinders. Is this an issue I ought to look for on my friend's bike? It's common on the 80's model Suzuki GSes. If we run Mikuni BS-CV carbs, it seems like this might be a shared issue.

Third question...If you're not hip to www.cycleorings.com, you should be. This guy's got the hookup on Mikuni o-rings that might save you a bundle on rebuild kits. Just supply your own fuel bowl gaskets (and float needle seats....if you gouge the hell out of them removing them like I do....) My question here is....where do the Yamaha wizards find parts? www.z1enterprises.com has a substantial selection for vintage Japanese bikes, but the insiders always know the best deals. I'm sure this '82 likely has never seen a valve adjustment. Where do I find shims? Does anyone have any suggestions above the valve adjustment procedure?

Thanks for your time and attention guy. If it makes you feel any better, I'm not a complete newb. I owned an '80 XS 850 triple. I adored that bike. It got repossessed in the foreclosure of my buddy's house. I always imagined what might have been......but the Suzuki brand came along, and I couldn't stop myself from a good deal. I guess this is fate's way of bringing me back to Yamaha.

Thanks once again.
-Brendon :thumbsup:
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An '82 would have BS34 carbs. The jets used should be the same as in your Suzuki carbs. Same type that is, probably different sizes though. You have to realize, you're powering two 325cc cylinders here, not four 162.5 ones.

There is no o-ring on the carb boots, they use a gasket. However, the boots do get bad, all dried out and cracked, and then they leak.

Many of us source our o-rings from McMaster-Carr, an industrial supply place. You must buy in quantity bags of 25 to 100 but the prices are much better than pretty much any place selling individual rings or small kits. There are several 650 specific parts suppliers. Two are MikesXS and 650Central. Many of the parts sold are repops and the quality sucks. Best you ask here before purchasing any items. We can tell you the good and bad.

The valve train doesn't use shims, it has simple screw and lock nut adjusters. All you need is a feeler gauge to measure and set the gaps.

The factory shop manual is on-line for free here .....

http://www.biker.net/650_service/650service main.html

Reading it would have answered all your questions and more. The main manual is for the '78 model but there are supplements to indicate the changes made to your buddy's later version. The motors are basically the same, changes were made to the carbs, ignition, and some of the electrical components.
Well quite the intro
look to carbs .
McMaster Carr is your friend
Valve adjust is nut and bolt , no shims required
Unlike the Suzuki no intake manifold o-ring is used but , yes, they are a source of leaks
Fairly simple bike that responds well to a thorough carb clean and valve adjust
They just arn't that complicated , until they are .

Gents, why do we respond to crap like this? The world seems full of guys who have money to spend on bikes that don't run, but are too cheap to buy a manual and too lazy to find out where they can get one free. I've given up on spoon feeding twits who deserve all the misery and frustration that their attitude earns.
Well, grizld, unlike most first posters that ask questions without info about there bike, other than two wheels, he did his best to describe another owners bike.
If It were me , ide do the same, and have, then hand the ball back to the owner.
I think the op posted a very good first post, with relevant info, enuf for us to help, and he gave us a link to a 0- ring supplier . Give and take.
I was referring to the buyer, not the OP, who has let himself get involved in a lazy idiot's drama. May he learn from the experience.
Wow, some sort of foreign fluid in yer Cheerios this morning or what? If you don't wanna answer a question, don't. How hard is that?

I will, on occasion just ask a panel of obviously knowledgeable people rather than muck around trying to find just the right search phrase and then wade through all the results trying to sort the wheat from the chaff.

Lazy, yes, but often effective.
I was referring to the buyer, not the OP, who has let himself get involved in a lazy idiot's drama. May he learn from the experience.
Maybe the buyer is off the grid? If he is, would you blame him for foldeing out of America's downward slide? I like adult websites, so I will stick around, pay my taxes,
Thanks for the backup guys. Yes, service manuals are readily available. Yes, full time work and grad school depletes the time I need to do proper research. Didn't mean to offend or stir up drama. Thank you to those who submitted their answer complete with links to handy information. I'll pass it on to my buddy.

Speaking of him, he's also got a '75 XS650B, which seems to be experiencing ignition problems. (Ugh. Points system) Can anyone link me to information regarding the '75 model?
+ 1 on what Gordon said.

The Tech menu can be a bit time consuming wading through all the chaff, do a Google search, top left, and the answers usually come up quicker.

Sounds like your friend is not only lazy but will take advantage of his friends. You are doing all the research and sounds like you will be doing the work on his bikes as well.

Show him the site and tell him to do as much research/reading in the tech menu.

There are tutorials video's and a carb guide, (This is the single most important thing to read).

Anything that there is to know about these bikes has been answered in there. People love to help out but it is also important that the owners help them selves, so that any help is just that, and not spoon feeding some one who is relying on others to do all the work.