These may be them, see post #27. I haven't tried them yet but maybe some day .....
http://www.xs650.com/threads/rebuilt-carbs-overflowing-random.15344/page-2
http://www.xs650.com/threads/rebuilt-carbs-overflowing-random.15344/page-2
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Parts reconnaissance is NEEDED!!! HELP PLEASE!
- Thread starter G_YamTech_314
- Start date
Not trying to be a pedant here, but confusion over terms can cause a real mess. The float valve seat is not a needle jet. The needle jet (AKA "atomizer," AKA "emulsion tube") is the brass jet above the main jet and below the slide needle. In Mikuni needle jets, a 1-digit size step is .0002", and it doesn't take much scrubbing with abrasives to do a lot of damage. The NJ is the primary metering component in the cruising range of the throttle, and a hogged out NJ will result in fuel consumption in the 30 to 35 mpg. range.
Yea answers can be confusing.........One says don;t get kits, another says some parts off kits can be used, (may save money compared to buying separate parts).
Have to do some work your self and find out what is needed then an answer will reveal itself.......The old keyster Carb kits had the rep for parts not working for the yaer carb..........
With new players in the market i don't think anyone has done a proper valuation of their parts and fit-ability..........
Old information may not be relevant in today;s market.........??
Based upon my experience, I readily endorse the aforementioned suggestions of initially attempting to re-purpose OEM carb parts, including gaskets.
I'll add this: Close inspection of each part under an intensely bright shop light, including the use of a magnifying glass, can reveal wear patterns, corrosion, particulate build-up and areas of leakage which could require your intervention.
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I'll add this: Close inspection of each part under an intensely bright shop light, including the use of a magnifying glass, can reveal wear patterns, corrosion, particulate build-up and areas of leakage which could require your intervention.
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Another gotcha.
I found erosion had been slowly opening up the orifices in my 45-year-old pilot jets. Unnoticeable by eye, had to use pin gauges to determine the actual orifice sizes.
Carbs have come and gone thru this forum in all manner of conditions. Some in good shape that respond to cleaning, new parts, and by-the-book tuning. Others with all manner of oddities, from abuse/ignorance, manufacturing flaws, hidden damage, part intermixing, severe wear, chemical attack. Scrutinize everything, research carb-related posts in here, expect the unexpected.
Coupla good carb adventures in these epic threads:
Mailman's thread, post #1 has an index of subjects.
http://www.xs650.com/threads/my-60th-birthday-present.47639/
And,
http://www.xs650.com/threads/carburetor-body-worn.48164/#post-486448
RobinC's thread:
http://www.xs650.com/threads/on-the-road-again-at-40-the-bike-that-is.49360/
Some of my carb challenges in this album:
http://www.xs650.com/media/albums/1971-xs1b-bs38-carburetor-rebuild.2684/
I found erosion had been slowly opening up the orifices in my 45-year-old pilot jets. Unnoticeable by eye, had to use pin gauges to determine the actual orifice sizes.
Carbs have come and gone thru this forum in all manner of conditions. Some in good shape that respond to cleaning, new parts, and by-the-book tuning. Others with all manner of oddities, from abuse/ignorance, manufacturing flaws, hidden damage, part intermixing, severe wear, chemical attack. Scrutinize everything, research carb-related posts in here, expect the unexpected.
Coupla good carb adventures in these epic threads:
Mailman's thread, post #1 has an index of subjects.
http://www.xs650.com/threads/my-60th-birthday-present.47639/
And,
http://www.xs650.com/threads/carburetor-body-worn.48164/#post-486448
RobinC's thread:
http://www.xs650.com/threads/on-the-road-again-at-40-the-bike-that-is.49360/
Some of my carb challenges in this album:
http://www.xs650.com/media/albums/1971-xs1b-bs38-carburetor-rebuild.2684/
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Most of the bad carbs and jets I've encountered have resulted from them sitting a long time all varnished and gummed up. That fuel residue seems to eat away at the metal, enlarging jet orifices and/or the holes in the carb body.
I had a very similar carb on my old 78 IT400. It was a Mikuni as well (Yamaha and Mikuni worked together as we all know. And when it leaked air found that it was the over flow tube but this set of carbs isn’t set up that way. In fact, I can’t quite recall how the overflow is set up on these. I’d be almost willing to garuntee it just needs new seat and needle valve (sorry for mistakingly calling it a needle jet...) I’d like to get my hands on an external float measuring tool. In school we used the manual slide adjusted tool, never really liked that method...
I’m here to update you all that I found (I think) the proper links to the manuals for my specific bike. I have one very vital question...
Can I use the XS650B (1975 I believe) on the 76 model? The 76 is an XS650C if so remember correctly. I’d imagine the specs are virtually identical yes? Did a good skimming tonight and it all looks damn familiar...
Can I use the XS650B (1975 I believe) on the 76 model? The 76 is an XS650C if so remember correctly. I’d imagine the specs are virtually identical yes? Did a good skimming tonight and it all looks damn familiar...
Caution with the mid-70s versions.
Major carb changes starting with '76.
Tranny changes starting somewhere in '77.
May be more, but that's outside my area of knowledge...
Major carb changes starting with '76.
Tranny changes starting somewhere in '77.
May be more, but that's outside my area of knowledge...
Yamaha didn't publish full manuals for every model year. A full manual came out every couple of years and supplements were published for the in between years. Your '76 got a supplement, to used with the last earlier full manual which came out in '74. But your bike has a later front end swapped on so will require the '78 and later manual for that.
That's kind of what I was thinking. I'm just glad I found the manuals for it. I'm gonna he looking into the front end more when I need to figure out the turn signal relay issue. As well as front brake light switch and other front end issues. I feel much more confident in doing work on the rig with manuals to help me though. Correct me if I'm wrong, but the manuals from the 70's have a lot more to offer than late 90's and early 2000's... The information is more in depth and doesn't leave quite as much guess work.
You can download all the manuals you need/want for free from the XS Cafe web site. I suggest getting the early full one that applies to your bike along with it's specific year supplement. Also get the '78 and later manual for your front end and brake.
https://thexscafedotcom.wordpress.com/2011/01/10/xs650-manuals/
There are also parts manuals there, which can be a big help just for showing how things go together. Most of us eventually try to acquire paper copies, real books, because they're just easier to use while working on the bike. Watch eBay, reasonably priced copies pop up all the time. Most of us also agree that the factory manuals are best. The aftermarket Haynes and Clymer manuals are not as good. Here's one to watch. It would be a good one to get because it is a combination of the earlier full manual and some later year supplements .....
https://www.ebay.com/itm/Rare-1974-...=item443727ea6c:g:1pgAAOSwjF9cTHK9:rk:13:pf:0
https://thexscafedotcom.wordpress.com/2011/01/10/xs650-manuals/
There are also parts manuals there, which can be a big help just for showing how things go together. Most of us eventually try to acquire paper copies, real books, because they're just easier to use while working on the bike. Watch eBay, reasonably priced copies pop up all the time. Most of us also agree that the factory manuals are best. The aftermarket Haynes and Clymer manuals are not as good. Here's one to watch. It would be a good one to get because it is a combination of the earlier full manual and some later year supplements .....
https://www.ebay.com/itm/Rare-1974-...=item443727ea6c:g:1pgAAOSwjF9cTHK9:rk:13:pf:0
I downloaded those! They're awesome. I saw Yamaha still sells print on demand manuals for the bike but it's $90...
A paper/bound manual takes on character over the years, and can become the heart of your shop library and your heritage as a shadetree mechanic.
Then perhaps pass it on to a younger person at some point.
There are some which I have cherished; as a teenager, I had only one resource for bug repair and rebuilding of VW engines, and it will be with me "when I go."
Then perhaps pass it on to a younger person at some point.
There are some which I have cherished; as a teenager, I had only one resource for bug repair and rebuilding of VW engines, and it will be with me "when I go."
http://biker.net/ is back up and running with some new information.......The site has a full set of parts files taken from Yamaha Fish files. https://web.archive.org/web/20160425134737/http://www.biker.net/650parts_index.html These can be downloaded fron the links on the left and they are area specific...........easy to just download a page from, say the forks from a 77 and other parts from different years..PDF that cab be simply converted to JPEG and printed if your just looking for a specific area..............Jean Aker, (site owner) has a lot of personal information on his bikes, XS650s and XS750s and some handy/helpful hints
Techman
XS650 Member
We like the way you have charted out the options. I have been building motors for years and have seen many of sump filters and oil filters. MikesXS parts work just fine. Trust me replacing that sump filter gasket on the bike is a pain. Ensuring both the mating surfaces is critical and clean is the key. Those older gaskets are pretty tough sometimes and working upside down - no fun! Be sure to get out a small acid brush and good gel paint remover to assist in softening and removal of that old hardened gasket. The filters themselves are metal screen and cleanable. Be sure to look at the original sump filter to not have any openings around the screen attachment. If you see heavy deposits of metal or opening on the original filter, I suggest a filter exchange. MikesXS has good tech advise when it comes to any questions with the 650's. Never hesitate to contact them directly.
Yup, a Royal Pain.
My solution is to hoist the bike above my head (I have a tall garage ceiling with an electric hoist) to work directly at it.
But our late friend, Robin C. described leaning the bike way, way, way over on it's side and somehow easily propping it there, to expose the sump.
Maybe someone can come up with a photo of this "lean over" method.
Carpet scraps or cardboard on floor, a 5 gallon bucket to set the handlebar end on. But I mostly twist around and scrape while it's on the centerstand, on the lift table.
