2005 kawi ninja 250r vacuum not sucking fuel from petcock

Ninjas · February 4th, 2018, 10:15 AM

Ok, so here's what's been done. We've had to replace a piston, as we all know, rockers, cams, etc all had to be removed for this. Everything was put together again after the new piston and rings were installed.

The issue is this, my carbs are not pulling fuel through the vacuum supply line. It seems to be positive vacuum instead of negative vacuum.

Does anyone know or have any ideas? My brain is racked, I've checked about everything I could, except the carbs, which is my next task. The bike was running completely fine up until #2 piston had a dime sized hole directly in the center. Im hoping it's just something that I overlooked due to being tired.

DannoXYZ · February 4th, 2018, 11:19 AM

Hose reversed at petcock?
Or hoses at carbs?

Measure vacuum coming from carbs, needs at least 10 in.Hg.

Ninjas · February 4th, 2018, 11:24 AM

Quote:

Originally Posted by JacRyann

Hose reversed at petcock?

Measure vacuum coming carbs, needs at least 10 in.Hg.

I'll do that as soon as I find a place that has a vacuum gauge. Aside from that, it's blowing air(it shouldn't be blowing) rather than sucking air, keeping my petcock vac diaphragm shut. Hoses are in the same positioning as when the bike was running fine before the piston fragged.

DannoXYZ · February 4th, 2018, 11:36 AM

Check your valve-clearances and cam-timing if it's puffing air instead of sucking.

Ninjas · February 4th, 2018, 11:41 AM

Quote:

Originally Posted by JacRyann

Check your valve-clearances and cam-timing if it's puffing air instead of sucking.

Because of having to replacing the piston, that's basically what I was fearing. I'll have to see if I can find any additional info than the (not so clear) manual.

Thank you for your suggestions.

jkv45 · February 4th, 2018, 04:50 PM

That is odd.

Re-check the cam timing to make sure the valves are opening at the proper time.

Make sure you have the correct hose from the carb connected to the petcock - https://faq.ninja250.org/wiki/File:Annotated_1.jpg

When you said - " my carbs are not pulling fuel through the vacuum supply line ... " - what do you mean? There shouldn't be fuel in that line - just vacuum to open the petcock.

Ninjas · February 4th, 2018, 05:28 PM

Quote:

Originally Posted by JacRyann

Check your valve-clearances and cam-timing if it's puffing air instead of sucking.

we've checked The timing, etc. Should be spot on. Yet the carbs vacuum for the fuel supply is still blowing air instead of sucking. Something isn't right..

Z1R rider · February 5th, 2018, 06:04 AM

Quote:

Originally Posted by Ninjas

still blowing air instead of sucking. Something isn't right..

intake valves bent, pieces of piston stuck under intake valve? Is it running now or are you just cranking it?

Ninjas · February 5th, 2018, 06:06 AM

Quote:

Originally Posted by Z1R rider

intake valves bent, pieces of piston stuck under intake valve? Is it running now or are you just cranking it?

We got it. Timing was off 180°. Thank you guys for your input. Much appreciated!

Stay safe!

Ninjas · July 4th, 2018, 08:48 PM

Quote:

Originally Posted by jkv45

That is odd.

Re-check the cam timing to make sure the valves are opening at the proper time.

Make sure you have the correct hose from the carb connected to the petcock - https://faq.ninja250.org/wiki/File:Annotated_1.jpg

When you said - " my carbs are not pulling fuel through the vacuum supply line ... " - what do you mean? There shouldn't be fuel in that line - just vacuum to open the petcock.

I didn't mean fuel through the vac line, I should have worded that differently. But it was the timing, 180° off. Fixed and is doing excellent. IG ninja_biker1_phx_az I have a few videos and photos there of after the repairs.

DannoXYZ · July 4th, 2018, 09:22 PM

How did you determine it was 180-degrees off?

Ninjas · July 5th, 2018, 12:07 AM

Quote:

Originally Posted by DannoXYZ

How did you determine it was 180-degrees off?

There was positive vacuum instead of negative vacuum. IF memory serves, positive vacuum pushes, while negative pulls(sucks) which indicated there was something very wrong with the timing. After checking the timing after noticing this the markings on the cams werent lining up correctly. I figure when i put tension on the timing chain i may have rotated the cams by mistake.

maverick9611 · July 5th, 2018, 12:25 AM

when you rotate cams to get your phasing make sure you keep your thumb pressed up against cam chain guide via cam chain tensioner housing. this will keep your chain chain from jumping teeth while setting your time

Ninjas · July 5th, 2018, 12:29 AM

Quote:

Originally Posted by maverick9611

when you rotate cams to get your phasing make sure you keep your thumb pressed up against cam chain guide via cam chain tensioner housing. this will keep your chain chain from jumping teeth while setting your time

Thank you for that advice, maverick. I'll keep note of that for the next go around. The timing was corrected 6 months ago and she's ran fine since

DannoXYZ · July 5th, 2018, 06:28 AM

Quote:

Originally Posted by Ninjas

After checking the timing after noticing this the markings on the cams werent lining up correctly. I figure when i put tension on the timing chain i may have rotated the cams by mistake.

Ah, so the marks were off by 180? I was wondering if it's possible to be off but have the marks look ok.

February 4th, 2018, 10:15 AM	#1
Ninjas Motorcyclist Name: Frank Location: Phoenix Arizona Join Date: May 2017 Motorcycle(s): Kawasaki ninja 250r Posts: 48	2005 kawi ninja 250r vacuum not sucking fuel from petcock Ok, so here's what's been done. We've had to replace a piston, as we all know, rockers, cams, etc all had to be removed for this. Everything was put together again after the new piston and rings were installed. The issue is this, my carbs are not pulling fuel through the vacuum supply line. It seems to be positive vacuum instead of negative vacuum. Does anyone know or have any ideas? My brain is racked, I've checked about everything I could, except the carbs, which is my next task. The bike was running completely fine up until #2 piston had a dime sized hole directly in the center. Im hoping it's just something that I overlooked due to being tired. __________________________________________________ At one point while checking sparks on the plugs it decided that my hand was a better earth than the frame.

July 5th, 2018, 12:25 AM	#13
maverick9611 "a legend in my own mind" Name: maverick9611 Location: Augusta,Georgia Join Date: May 2017 Motorcycle(s): 2015 moto guzzi norge(brownie),2020 aprilia dorsoduro, Posts: A lot. MOTM - Feb '18	when you rotate cams to get your phasing make sure you keep your thumb pressed up against cam chain guide via cam chain tensioner housing. this will keep your chain chain from jumping teeth while setting your time __________________________________________________ "trying not to get old"

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February 4th, 2018, 11:19 AM	#2
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	Hose reversed at petcock? Or hoses at carbs? Measure vacuum coming from carbs, needs at least 10 in.Hg. Last futzed with by DannoXYZ; February 4th, 2018 at 02:28 PM.

February 4th, 2018, 11:36 AM	#4
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	Check your valve-clearances and cam-timing if it's puffing air instead of sucking.

February 4th, 2018, 04:50 PM	#6
jkv45 Rev Limiter Name: Jay Location: WI Join Date: Jul 2013 Motorcycle(s): '06 SV650n, '00 Derbi GPR, '64 CA77 Dream 305, '70 CL450 Scrambler, numerous dirt bikes Posts: A lot. MOTM - Jun '18, Oct '16	That is odd. Re-check the cam timing to make sure the valves are opening at the proper time. Make sure you have the correct hose from the carb connected to the petcock - https://faq.ninja250.org/wiki/File:Annotated_1.jpg When you said - " my carbs are* not pulling fuel through the vacuum supply line ... "* - what do you mean? There shouldn't be fuel in that line - just vacuum to open the petcock.

July 4th, 2018, 09:22 PM	#11
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	How did you determine it was 180-degrees off?