Carb vacuum line question

Tsmith9233 · June 13th, 2020, 10:28 AM

I have an 03 machine with a 12 engine. I swapped the stock 03 carbs for stock 12 carbs. The 12 set has a tee and a second hose in the vacuum line that connects to petcock. I thought it might go to the nipple at rear of gas tank, but doesn’t reach. I assume I do not want a wild vacuum leak. Do I extend it to attach to tank or plug it off or???? Thanks in advance.

ducatiman · June 13th, 2020, 10:55 AM

plug it or eliminate the T entirely using continuous hose, petcock to LH carb vac nipple direct.

I surmise the T fitting arrangement was actually meant to run off the carb *vent system* not the *vacuum system* of the carb so its possible it was "piped" wrong by PO of the carbs. Yessir, a giant vacuum leak. I can hear him now...runs like crap..these 250's suck!

Verify the actual vent is clear to....ummm, vent. If hose present, no kinks or crimps! Free and clear 100%

Tsmith9233 · June 13th, 2020, 11:20 AM

I know I have a Frankenstein machine, probably take a while to get it sorted. Hopefully you all can assist along the way... will swap out that hose pronto.

Tsmith9233 · June 13th, 2020, 12:36 PM

Eliminated the T and put one piece hose from carb to petcock. Is there supposed to be a hose attached to nipple on tank? If so, from where does it come? What’s the other end attached to? Thanks again

nocturncal · June 13th, 2020, 01:00 PM

Found this in another post

https://faq.ninja250.org/wiki/Hose_r...ine_fuel_tanks

On the 49 state tank there's the one hose outlet (drain).
49 state models have only one hose coming from the rear of the fuel tank. This is a drain hose for fluid that gets in the depression between the filler neck and the top of the tank, from being in the rain or overfilling the tank. Air vents into these tanks

On the Cali tank there's 3 (L-R), with the middle apparently the drain.
The right tube allows air into the fuel tank through the gas cap as the gas level drops. This tube must remain open.

The middle tube is the drain and should keep the stock routing under the bike in the hose cluster (right-hand side of the frame, as discussed above).

The left tube circulates fumes to the emissions system and should be capped off.

DannoXYZ · June 13th, 2020, 03:10 PM

Here's some pictures to double-check vacuum-hose routing. Many times, you may inherit incorrect routing from previous owners.

Not shown is vent-hose from centre of fuel-rail that should go backwards between carb-inlets at airbox and down to ground by rear-shock. Drain-hose from tank shoud also end up down there.

ducatiman · June 14th, 2020, 07:01 AM

In pic that open T between RH carb vac barb and decel valve must be eliminated if present in any non-Ca bike. Continuous hose preferred. In ANY application, it should never be left open.

I believe that T is piped to the Ca model canister.

Thankfully, only encountered 1 Ca model EX500 here many years ago, service access complicated by all the extra junk.

Hmmmm....REMOVE?

June 13th, 2020, 10:28 AM	#1
Tsmith9233 ninjette.org member Name: Tom Location: Seneca Falls, NY Join Date: Jun 2020 Motorcycle(s): 03 ninja 250 Posts: 14	Carb vacuum line question I have an 03 machine with a 12 engine. I swapped the stock 03 carbs for stock 12 carbs. The 12 set has a tee and a second hose in the vacuum line that connects to petcock. I thought it might go to the nipple at rear of gas tank, but doesn’t reach. I assume I do not want a wild vacuum leak. Do I extend it to attach to tank or plug it off or???? Thanks in advance.

June 13th, 2020, 10:55 AM	#2
ducatiman ninjette.org certified postwhore Name: Gordon Location: new york Join Date: Sep 2009 Motorcycle(s): '95 DUCATI 900SS/SP '07 DUCATI SS800 '19 HONDA CBR650R Posts: A lot. MOTM - Nov '18, Mar '17	plug it or eliminate the T entirely using continuous hose, petcock to LH carb vac nipple direct. I surmise the T fitting arrangement was actually meant to run off the carb vent system not the vacuum system of the carb so its possible it was "piped" wrong by PO of the carbs. Yessir, a giant vacuum leak. I can hear him now...runs like crap..these 250's suck! Verify the actual vent is clear to....ummm, vent. If hose present, no kinks or crimps! Free and clear 100% __________________________________________________ gordon@customcarbservices.com Custom Carb Service www.customcarbservices.com

June 13th, 2020, 03:10 PM	#6
DannoXYZ ninjette.org certified postwhore Name: AKA JacRyann Location: Mesa, AZ Join Date: Dec 2011 Motorcycle(s): CB125T CBR250R-MC19 CBR250RR-MC22 NSR350R-MC21 VF500F CBR600RR SFV650 VFR750F R1M ST1300PA Valkyrie-F6C Posts: A lot. MOTY - 2018, MOTM - Nov '17	Here's some pictures to double-check vacuum-hose routing. Many times, you may inherit incorrect routing from previous owners. Not shown is vent-hose from centre of fuel-rail that should go backwards between carb-inlets at airbox and down to ground by rear-shock. Drain-hose from tank shoud also end up down there. Last futzed with by DannoXYZ; June 13th, 2020 at 06:48 PM.

June 14th, 2020, 07:01 AM	#7
ducatiman ninjette.org certified postwhore Name: Gordon Location: new york Join Date: Sep 2009 Motorcycle(s): '95 DUCATI 900SS/SP '07 DUCATI SS800 '19 HONDA CBR650R Posts: A lot. MOTM - Nov '18, Mar '17	In pic that open T between RH carb vac barb and decel valve must be eliminated if present in any non-Ca bike. Continuous hose preferred. In ANY application, it should never be left open. I believe that T is piped to the Ca model canister. Thankfully, only encountered 1 Ca model EX500 here many years ago, service access complicated by all the extra junk. Hmmmm....REMOVE? __________________________________________________ gordon@customcarbservices.com Custom Carb Service www.customcarbservices.com
	1 out of 1 members found this post helpful.

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June 13th, 2020, 11:20 AM	#3
Tsmith9233 ninjette.org member Name: Tom Location: Seneca Falls, NY Join Date: Jun 2020 Motorcycle(s): 03 ninja 250 Posts: 14	I know I have a Frankenstein machine, probably take a while to get it sorted. Hopefully you all can assist along the way... will swap out that hose pronto.

June 13th, 2020, 12:36 PM	#4
Tsmith9233 ninjette.org member Name: Tom Location: Seneca Falls, NY Join Date: Jun 2020 Motorcycle(s): 03 ninja 250 Posts: 14	Eliminated the T and put one piece hose from carb to petcock. Is there supposed to be a hose attached to nipple on tank? If so, from where does it come? What’s the other end attached to? Thanks again

June 13th, 2020, 01:00 PM	#5
nocturncal ninjette.org member Name: Cal Location: San Francisco Join Date: Jun 2017 Motorcycle(s): '09 Ninja 250R Posts: 180	Found this in another post https://faq.ninja250.org/wiki/Hose_r...ine_fuel_tanks On the 49 state tank there's the one hose outlet (drain). 49 state models have only one hose coming from the rear of the fuel tank. This is a drain hose for fluid that gets in the depression between the filler neck and the top of the tank, from being in the rain or overfilling the tank. Air vents into these tanks On the Cali tank there's 3 (L-R), with the middle apparently the drain. The right tube allows air into the fuel tank through the gas cap as the gas level drops. This tube must remain open. The middle tube is the drain and should keep the stock routing under the bike in the hose cluster (right-hand side of the frame, as discussed above). The left tube circulates fumes to the emissions system and should be capped off.