First time rehab of a 1976ish basket case

Should I cut down front fender or leave it?

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Best tip i ever had was......When taking something apart for the first time, take each part out reinstall it then do the procedure 2 or 3 times........... Do one carb body at a time and take pics......... If a problem arises the second carb can be used as a reference.
 
650Skull said:
Best tip i ever had was......When taking something apart for the first time, take each part out reinstall it then do the procedure 2 or 3 times........... Do one carb body at a time and take pics......... If a problem arises the second carb can be used as a reference.
Click to expand...
Brilliant advice, makes perfect sense too.its not often that you have a pre assembled duplicate of something to reference while working! Thanks
 
Good morning y'all, ok i ordered a set of needle jet o rings to replace the non-existing ones and 4 throttle body/butterly shaft seals. I'm now searching for a set of choke body and float bowl gaskets. Mikes has the the choke bodies but not the bowl gaskets (not without the full kit apparently) but I found them on https://www.xs650shop.com/products/gasket-float-bowl-mikuni-bs38-cv-carburetors anyone have experience with them? looking for a good place to source jets too, as per 5twins advice upsizing to 27.5 pilots and 130/132.5 mains to combat predicted leaning from having properly sealed needle jets. Should I just use jetsrus or is there a better source? I'd rather put money back into a forum member's pockets!
 
I pretty much never remove the choke housings. The passages in them are quite large and don't plug up. You can remove the choke plunger from the housing if you like. Then you can clean out it's hole, clean the plunger, and inspect it's rubber sealing tip. Maybe I've been lucky but I've never found a bad one.

For jets, all I will recommend is that you get genuine Mikuni ones. Shop around on the web and find your best price. I think retail is about $4 per jet but many places charge more than that. Be sure you get the correct type pilot jets. Two types were used in the 650 carbs over the years, the BS30/96 and the VM22/210. They look very similar and will physically interchange, but you must use the type your particular carb set was designed to use. In the case of your '76-'77 carb set, that is the VM22/210 type pilot. You can tell the 2 apart by which end of the jet has the metering orifice .....

Uoaj1xt.jpg


You may have noticed your original pilots have no air bleed holes down the sides. You won't be finding replacements like that but that's OK. The standard style with the bleed holes work just fine. Apparently, Yamaha contracted with Mikuni to have these no-bleed-hole jets made special for them while they were producing the bikes. The only way to get replacements like that now would be to scrounge them from other carb sets of the time. In your case, the '78-'79 BS38s came with no-hole 27.5 VM22/210 pilots.
 
Hey greasy. I found Mike's choke gaskets super thin. Cut my own from a roll of Felpro gasket material.

I buy float bowl gaskets from a local Yamaha parts supplier. They are still available OEM from Yamaha.
 
Yeah, I'm a couple pages behind...….Do not soak those carbs for a long time in PineSol, they'll turn black, better to not use it at all.

Good start on the wiring, but open barrel connectors are best, different crimper needed for open barrel.

Solder, lead free solder sucks. The best electrical solder with lead is made in Mexico.:shrug:

Scott
 
5twins said:
I pretty much never remove the choke housings. The passages in them are quite large and don't plug up. You can remove the choke plunger from the housing if you like. Then you can clean out it's hole, clean the plunger, and inspect it's rubber sealing tip. Maybe I've been lucky but I've never found a bad one.

For jets, all I will recommend is that you get genuine Mikuni ones. Shop around on the web and find your best price. I think retail is about $4 per jet but many places charge more than that. Be sure you get the correct type pilot jets. Two types were used in the 650 carbs over the years, the BS30/96 and the VM22/210. They look very similar and will physically interchange, but you must use the type your particular carb set was designed to use. In the case of your '76-'77 carb set, that is the VM22/210 type pilot. You can tell the 2 apart by which end of the jet has the metering orifice .....

Uoaj1xt.jpg


You may have noticed your original pilots have no air bleed holes down the sides. You won't be finding replacements like that but that's OK. The standard style with the bleed holes work just fine. Apparently, Yamaha contracted with Mikuni to have these no-bleed-hole jets made special for them while they were producing the bikes. The only way to get replacements like that now would be to scrounge them from other carb sets of the time. In your case, the '78-'79 BS38s came with no-hole 27.5 VM22/210 pilots.
Click to expand...

Thanks 5t, I did notice the difference, and lack of availability on the pilots but I think I found some https://jetsrus.com/a_jets_by_carburetor_type/jets_mikuni_N151.067_pilot.htm they are marked as N151.067 are these not compatible? You'll see smallest size is 30.. unsure. I'll be following jims advice and using NCS to get what I can
 
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robinc said:
Hey greasy. I found Mike's choke gaskets super thin. Cut my own from a roll of Felpro gasket material.

I buy float bowl gaskets from a local Yamaha parts supplier. They are still available OEM from Yamaha.
Click to expand...
Thanks for the heads up, if they end up leaking I'll go the felpro route. They weren't, but they got a pretty heavy blast of carb cleaner... so we'll see what happens on reassembly
 
mrtwowheel said:
Yeah, I'm a couple pages behind...….Do not soak those carbs for a long time in PineSol, they'll turn black, better to not use it at all.

Good start on the wiring, but open barrel connectors are best, different crimper needed for open barrel.

Solder, lead free solder sucks. The best electrical solder with lead is made in Mexico.:shrug:

Scott
Click to expand...
Thanks for the heads up on the pinesol. Opted against it when I found those tiny head electric toothbrushes at Walmart for $8! Detail cleanin made easier. As for the connectors, I got a big variety pack of these:
IMG_3480.JPG
did I mislabel them as bullet connectors? I'm still very ignorant to the elect. Terminology. Oh and I have some olddd leaded solder (my dad and his dad were both tattoo artists back when you had to solder your own needles!) that I planned to use to reinforce connections. Tin before crimping then alittle extra post crimp, is that the proper procedure?
*edit* I should clarify my father IS currently a tattoo artist
 
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JimD54 said:
Those connectors are "molex type". They need a special crimper. A lot of people feel you should not solder connectors, just crimp 'em. I'm not in that camp. I have no problem soldering a crimped connection.
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Thanks Jim, that's what I got so it's what I'm using, and it seems foolish not to solder if you've already got the equipment on hand and the time! I'll be grabbing a proper crimped as well
 
JimD54 said:
Those connectors are "molex type". They need a special crimper. A lot of people feel you should not solder connectors, just crimp 'em. I'm not in that camp. I have no problem soldering a crimped connection.
Click to expand...

Yeah, what Jim said about the special crimpers. "Open barrel" refers to the place where the wire crimps to the connector, those are open barrel type connectors that you have, much better than the hardware store/Walmart connectors that are available. I like those butane mini torches for soldering, don't use one if you are clumsy with tools, shouldn't have to pre-tin if you have good solder.

Scott
 
mrtwowheel said:
Yeah, what Jim said about the special crimpers. "Open barrel" refers to the place where the wire crimps to the connector, those are open barrel type connectors that you have, much better than the hardware store/Walmart connectors that are available. I like those butane mini torches for soldering, don't use one if you are clumsy with tools, shouldn't have to pre-tin if you have good solder.

Scott
Click to expand...
Sweet! I done good! Thanks for the confirmation. I've seen and like the idea of the microtorch for better sweating, but I'm afraid of melting insulation and stuff, and I'm pretty comfortable with an iron. We'll see, might find room in the budget for another tool :whistle:
 
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