One of the vexing problems our bikes are prone-to, is a blocked, obstructed, plugged pilot jet in the jet block. It's enough of a chore to get to the pilot jet, because the carbs have to come-off, split into at-least two, pairs, and then the float bowls have to come-off. SOmetimes I can wiggle the four float bowls off, sometimes I need to loosen the screws which hold the pairs together:
For the pair with the idle screw adjuster
the chrome bracket the float bowl vent tubes stick-through (and which holds the idle thumb screw)
the bracket which holds the throttle cable in-place (the one closest-to the 3-way gas inlet)
On the other pair of carbs, it's the rectangular bracket holding the carbs together, and the chrome bracket the float bowl vent tubes stick-through.
Because I was tearing-down these carbs for an immersion in the ultrasonic tank, I wanted to completley-remove the rubber gas lines.
On an old bike, and let's face it, the newest of the Gen 1 bikes is 13 years-old, you can easily-destroy the brittle gas lines by ham-fisted handling of them during the disassembly. I suggest that you consider replacing the gas lines on your bike if you're this-far into a carburetor tear-down. It's possible that you may never have to replace them again. Have you seen pics or videos, or an in-person event where a motorcycle's gas line hose ruptures, dumps fuel onto a hot exhaust pile and now the bike is a total-loss? Replace the hoses.
If you're really-cheap, you can use straight gas line tubing and a suitable T-fitting to replace that one unique molded-T gas line our bikes use. I'd just as-soon replace the brittle, old gas line with the OEM Yamaha part, they're nice and supple unlike that brittle, crusty, hard and inflexible hose on your twenty year-old ride. (or older!) Here it is:
Item #65
Hose-gas line T
26H-14987-00-00
$30.47
https://www.ronayers.com/oemparts/a/yam/500456a5f8700209bc79313a/carburetor
Here's where you can justify the cost of that Yamaha OEM molded-T gas line: replace the other gas line, for the other pair of carbs, with a piece of 1/4" gas line. The shops sell it by the foot, and buying a foot, will save you probably $20, as the Yamaha OEM straight piece of gas line is $$21.68. NAPA sells reinforced rubber hose, 1/4" I.D. for $1.49/foot; one foot is all you need. See? You just saved $20! Put that $20 towards the cost of the OEM Yamaha molded T-hose, and now that molded T-hose is only $10.47! In other words, $32 gets you an OEM Yamaha molded T-hose and a one foot length of NAPA 1/4" I.D. reinforced rubber hose. Get a couple of clamps of whatever type you prefer. I like the spring steel ones instead of the serrated stainless-steel hose clamps. If you buy the former, just be-sure to buy the ones sized to the proper O.D. of the gas line you buy.
Hose-gas line (this is the OEM Yamaha straight piece of hose. No-need to buy this when you can buy a piece at NAPA 1/4" I.D. for $1.49. Fiche is same as above.
Item #64
31H-14987-00-00
$21.68
Be very-careful with your jet blocks! These are discontinued from Yamaha!
There are a few things you should have on-hand to do this repair. Order the following:
Item #42
Jet, pilot
Size: (37.5)
4G0-14142-37-00 (discontinued #)
4G0-14142-37-A0 (current #)
$6.10 Buy four of them if you plan to keep your bike, they are somewhat easy to bugger the screwdriver slot (remember the purpose of this thread, eh?)
Item #35
Gasket, jet block
3JB-14199-00-00
$9.41 Buy four of them, as these often tear when disassembling the carburetors.
Item #43
Cap (for pilot jet hole, this is the small round rubber plug which fits into the pilot jet/jet block hole once the pilot jet is installed)
22V-14968-00-00
$6.10 I suggest buying at-least two, buy four if you're keeping the bike, replace them all.
Item #44
Pipe, main bleed (this is the middle hole/jet on the jet block, it too gets a rubber plug-below)
26H-1414G-00-00
$12.65 I suggest buying at-least two, buy four if you're keeping the bike, replace them all.
Item #45
Cap (for main bleed pipe hole, this is the small round rubber plug which fits into the main bleed pipe/jet block hole once the main bleed pipe is installed)
22U-14968-00-00
$6.18 I suggest buying at-least two, buy four if you're keeping the bike, replace them all.
Note that the rubber caps for the pilot jet and the main bleed pipe holes are different sizes.
end, Part I
For the pair with the idle screw adjuster
the chrome bracket the float bowl vent tubes stick-through (and which holds the idle thumb screw)
the bracket which holds the throttle cable in-place (the one closest-to the 3-way gas inlet)
On the other pair of carbs, it's the rectangular bracket holding the carbs together, and the chrome bracket the float bowl vent tubes stick-through.
Because I was tearing-down these carbs for an immersion in the ultrasonic tank, I wanted to completley-remove the rubber gas lines.
On an old bike, and let's face it, the newest of the Gen 1 bikes is 13 years-old, you can easily-destroy the brittle gas lines by ham-fisted handling of them during the disassembly. I suggest that you consider replacing the gas lines on your bike if you're this-far into a carburetor tear-down. It's possible that you may never have to replace them again. Have you seen pics or videos, or an in-person event where a motorcycle's gas line hose ruptures, dumps fuel onto a hot exhaust pile and now the bike is a total-loss? Replace the hoses.
If you're really-cheap, you can use straight gas line tubing and a suitable T-fitting to replace that one unique molded-T gas line our bikes use. I'd just as-soon replace the brittle, old gas line with the OEM Yamaha part, they're nice and supple unlike that brittle, crusty, hard and inflexible hose on your twenty year-old ride. (or older!) Here it is:
Item #65
Hose-gas line T
26H-14987-00-00
$30.47
https://www.ronayers.com/oemparts/a/yam/500456a5f8700209bc79313a/carburetor
Here's where you can justify the cost of that Yamaha OEM molded-T gas line: replace the other gas line, for the other pair of carbs, with a piece of 1/4" gas line. The shops sell it by the foot, and buying a foot, will save you probably $20, as the Yamaha OEM straight piece of gas line is $$21.68. NAPA sells reinforced rubber hose, 1/4" I.D. for $1.49/foot; one foot is all you need. See? You just saved $20! Put that $20 towards the cost of the OEM Yamaha molded T-hose, and now that molded T-hose is only $10.47! In other words, $32 gets you an OEM Yamaha molded T-hose and a one foot length of NAPA 1/4" I.D. reinforced rubber hose. Get a couple of clamps of whatever type you prefer. I like the spring steel ones instead of the serrated stainless-steel hose clamps. If you buy the former, just be-sure to buy the ones sized to the proper O.D. of the gas line you buy.
Hose-gas line (this is the OEM Yamaha straight piece of hose. No-need to buy this when you can buy a piece at NAPA 1/4" I.D. for $1.49. Fiche is same as above.
Item #64
31H-14987-00-00
$21.68
Be very-careful with your jet blocks! These are discontinued from Yamaha!
There are a few things you should have on-hand to do this repair. Order the following:
Item #42
Jet, pilot
Size: (37.5)
4G0-14142-37-A0 (current #)
$6.10 Buy four of them if you plan to keep your bike, they are somewhat easy to bugger the screwdriver slot (remember the purpose of this thread, eh?)
Item #35
Gasket, jet block
3JB-14199-00-00
$9.41 Buy four of them, as these often tear when disassembling the carburetors.
Item #43
Cap (for pilot jet hole, this is the small round rubber plug which fits into the pilot jet/jet block hole once the pilot jet is installed)
22V-14968-00-00
$6.10 I suggest buying at-least two, buy four if you're keeping the bike, replace them all.
Item #44
Pipe, main bleed (this is the middle hole/jet on the jet block, it too gets a rubber plug-below)
26H-1414G-00-00
$12.65 I suggest buying at-least two, buy four if you're keeping the bike, replace them all.
Item #45
Cap (for main bleed pipe hole, this is the small round rubber plug which fits into the main bleed pipe/jet block hole once the main bleed pipe is installed)
22U-14968-00-00
$6.18 I suggest buying at-least two, buy four if you're keeping the bike, replace them all.
Note that the rubber caps for the pilot jet and the main bleed pipe holes are different sizes.
end, Part I
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