07 Carb shenanigans

T4r4life · August 27th, 2018, 04:32 PM

So i just picked up a super cherry 07 with 600 miles on it, yes i know. bike has been sitting so i took the carb apart to clean it, cleaned the Main jet, pilot jet, fuel mixture port, choke port, main jet needle. i replaced the float needle and adjusted the float, bench sync the carbs, dipped the carb in chemtool, Blew b12 and compressed air through all the passage, you know, the whole works. But for some reason its doing some weird shenanigan.

The bike when cold will not start, it sounds like it wants to idle but its so low rpm that it just stalls. Even with full choke it won't start, matter of fact when i do pull the choke once it gets going it actually kills the bike.

i get the bike started with starting fluid and i let it warm up to working temp, idles perfect at 1300rpm, return to idle is perfect, rides perfect, no dead spot, lot of pull. so i thought hmm maybe the air cut off valve is killiing the bike, checked the air cut off diaphragm, looks brand new. The fuel screw is 2 turns out same as my other ninjas, ive worked on pre gen quiet a bit and im kinda lost right now, everything is super clean and all the rubber are in good shape. Hmmmm what can it be?

Pic of bike for attention

DannoXYZ · August 28th, 2018, 10:28 PM

The fact that bike is not running correctly means carbs are not fully cleaned. Sure, they may be better than before, but they are not factory-fresh as when they left factory.

Unfortunately, due to regulations, "carb cleaner" liquids are nothing more than weak carrier solvents without real cleaning/cutting chemicals. Back in old days, carbon-tetrachloride was awesome. I'd spray it on inside of my sprocket-guards and gunk would just slide off like hot butter. Then it was banned. Next best stuff, trichloroethane worked OK and was around for a while. But it too was banned.

When I spray stuff available now OTC onto my sprocket-guards, it runs off almost clear, having dissolved no grease and oil at all (I'd probably get better results peeing through carbs). So I don't give it much hope in cleaning carbs which have gas that have dried into plastic varnish. This is poly-vinyl cross-linked material similar to tung or linseed oil used in the old days as clear-coat/varnish. It's never dissolving again.

What is needed is mechanical scraping/flossing of all fuel-circuits in the carb-body itself. The jets are easily done with copper-wire or guitar string. You'll also need to soak carb & dis-assembled jets in ultrasonic cleaner for couple days. Then pressure soda-blast through all holes and passageways. One final step I do is drip dye I make with food-colouring through the passages to make sure it comes out other side. Same with every single hole in jets, especially pilot-jets with their multiple tiny holes. Each and every hole should have dye coming out before I consider them cleaned.

Some related threads:

https://www.ninjette.org/forums/showthread.php?t=322846
https://www.ninjette.org/forums/showthread.php?t=321223
https://www.ninjette.org/forums/showthread.php?t=315193
https://www.ninjette.org/forums/showthread.php?t=317977

Some of really good mechanical guys on here, guys who can rebuild engines using only their teeth with both hands tied behind their backs, have had to disassemble and "clean" their carbs more and more thoroughly 3, 4, 5 times before it was as clean as factory-fresh condition.

T4r4life · August 28th, 2018, 10:48 PM

i use mainly B12 and Berryman chemdip, and i use a brass wire wheel for all the big stuff, small copper wire for all the jets and such, but for the passages i just shoot compressed air through it and make sure it comes out of the other passages, but using a small bore cleaner might be a good idea. sigh i wish i have friends with ultrasonic cleaner that would make life so easy.

Quote:

Originally Posted by DannoXYZ

The fact that bike is not running correctly means carbs are not fully cleaned. Sure, they may be better than before, but they are not factory-fresh as when they left factory.

Unfortunately, due to regulations, "carb cleaner" liquids are nothing more than weak carrier solvents without real cleaning/cutting chemicals. Back in old days, carbon-tetrachloride was awesome. I'd spray it on inside of my sprocket-guards and gunk would just slide off like hot butter. Then it was banned. Next best stuff, trichloroethane worked OK and was around for a while. But it too was banned.

When I spray stuff available now OTC onto my sprocket-guards, it runs off almost clear, having dissolved no grease and oil at all (I'd probably get better results peeing through carbs). So I don't give it much hope in cleaning carbs which have gas that have dried into plastic varnish. This is poly-vinyl cross-linked material similar to tung or linseed oil used in the old days as clear-coat/varnish. It's never dissolving again.

What is needed is mechanical scraping/flossing of all fuel-circuits in the carb-body itself. The jets are easily done with copper-wire or guitar string. You'll also need to soak carb & dis-assembled jets in ultrasonic cleaner for couple days. Then pressure soda-blast through all holes and passageways. One final step I do is drip dye I make with food-colouring through the passages to make sure it comes out other side. Same with every single hole in jets, especially pilot-jets with their multiple tiny holes. Each and every hole should have dye coming out before I consider them cleaned.

Some related threads:

https://www.ninjette.org/forums/showthread.php?t=322846
https://www.ninjette.org/forums/showthread.php?t=321223
https://www.ninjette.org/forums/showthread.php?t=315193
https://www.ninjette.org/forums/showthread.php?t=317977

Some of really good mechanical guys on here, guys who can rebuild engines using only their teeth with both hands tied behind their backs, have had to disassemble and "clean" their carbs more and more thoroughly 3, 4, 5 times before it was as clean as factory-fresh condition.

DannoXYZ · August 29th, 2018, 07:33 PM

Quote:

Originally Posted by T4r4life

i use mainly B12 and Berryman chemdip, ...

Looking at MSDS sheet for ChemDip shows it's mostly water!!! No chlorinated cleaners at all! And ETHANOLS! It's ethanol in gas that started this whole mess anyway. Nope, I re-affirm my conclusion that pee is better than ANY kind of OTC carb-cleaning product. It's also mostly water too!

Best cleaner to get is something with healthy dose of PEA such as Red Line SI-1, Techron Concentrate or 3M Max Strength Fuel System Cleaner. Use whole bottle cut with enough gas to completely cover and soak carbs for couple days (1/2-gallon gas or so).

Then find some kind of wire to floss out all fuel-circuits. Doesn't matter if jets at end of circuits are clear, if pipe sending them fuel is clogged, nothing's getting out jets.

After 1/2-day of flossing (that's 12-hours, not 4), re-soak them in PEA for couple more days. During these days of waiting, search, track down, rent ultrasonic cleaner and soda-blasting equipment.

Quote:

Originally Posted by n4mwd

Here are the secret passages in the carbs. They are kind of hard to figure out sometimes and this picture guide will show where they are for cleaning purposes.

Carb Pilot jet Circuit

Carb Main Jet Circuit

Carb Fuel and Overflow Drain

Carb Diaphragm Intake, upper choke and vacuum ports

Carb Choke Circuit

Also you want pilot screws 2.75 turns out on left carb and 2.25 turns out on right one.

jkv45 · August 30th, 2018, 05:58 AM

Quote:

Originally Posted by DannoXYZ

(SNIP) 2.75 turns out on left carb and 2.25 turns out on right one.

Hey Danno -

What the reason for the difference in L to R idle mixture adjustments?

I thought the New Gens had different parts and settings side to side, but I've always set the Pre Gen carbs the same.

Triple Jim · August 30th, 2018, 06:29 AM

I know you said 600 miles, but things can be deceptive. Are you sure the odometer is original, for example?

Valves that are out of adjustment can cause your symptoms. On this engine, wear tends to cause the valve clearances to be reduced, and they eventually get to where they don't quite close when the engine is cold. This was the case when I got my '05, and I had similar hard starting and difficulty idling until it warmed up, at which time it ran fine. You can get a rough idea if this is the problem by doing a compression test on the cold engine, or you can just check the clearances.

https://faq.ninja250.org/wiki/How_do..._the_valves%3F

T4r4life · September 10th, 2018, 04:32 PM

Good new everyone! i got the bike running smooth as butter now, the AF ratio screw for some reason are not the same on both side, when i turn the screw all the way in, one needle sticks out more than the other. so the first thing i did is order to the stage 1 jet kit and got rid of the small tiny jets these california bikes came with, and got a #40 idle, and #110 main. with new jets the bike runs a little better but still pretty bad, got the bike to operating temp with some starting fluid and started the carb sync, got the carb perfectly synced. it runs a little better, but again not perfect. rode it to my buddys house, and he tuned the AF screw on the bike with it running. He got a handy little tool that can adjust AF with the carb on the bike. man oh man is it good now, zero lag on throttle, perfect return to idle, perfect power. its just perfect. im stoked!

jkv45 · September 11th, 2018, 06:19 AM

Good to hear you got it going.

110 is a pretty big Main Jet if you are running the stock airbox and exhaust.

We ran a 108 with pods and a leaky exhaust.

With 40 Pilots you should not be as far out on the idle mixture screws as you would with stock 38s, but it should end up providing the same mixture.

August 28th, 2018, 10:28 PM	#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	The fact that bike is not running correctly means carbs are not fully cleaned. Sure, they may be better than before, but they are not factory-fresh as when they left factory. Unfortunately, due to regulations, "carb cleaner" liquids are nothing more than weak carrier solvents without real cleaning/cutting chemicals. Back in old days, carbon-tetrachloride was awesome. I'd spray it on inside of my sprocket-guards and gunk would just slide off like hot butter. Then it was banned. Next best stuff, trichloroethane worked OK and was around for a while. But it too was banned. When I spray stuff available now OTC onto my sprocket-guards, it runs off almost clear, having dissolved no grease and oil at all (I'd probably get better results peeing through carbs). So I don't give it much hope in cleaning carbs which have gas that have dried into plastic varnish. This is poly-vinyl cross-linked material similar to tung or linseed oil used in the old days as clear-coat/varnish. It's never dissolving again. What is needed is mechanical scraping/flossing of all fuel-circuits in the carb-body itself. The jets are easily done with copper-wire or guitar string. You'll also need to soak carb & dis-assembled jets in ultrasonic cleaner for couple days. Then pressure soda-blast through all holes and passageways. One final step I do is drip dye I make with food-colouring through the passages to make sure it comes out other side. Same with every single hole in jets, especially pilot-jets with their multiple tiny holes. Each and every hole should have dye coming out before I consider them cleaned. Some related threads: https://www.ninjette.org/forums/showthread.php?t=322846 https://www.ninjette.org/forums/showthread.php?t=321223 https://www.ninjette.org/forums/showthread.php?t=315193 https://www.ninjette.org/forums/showthread.php?t=317977 Some of really good mechanical guys on here, guys who can rebuild engines using only their teeth with both hands tied behind their backs, have had to disassemble and "clean" their carbs more and more thoroughly 3, 4, 5 times before it was as clean as factory-fresh condition.
	1 out of 1 members found this post helpful.

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August 27th, 2018, 04:32 PM	#1
T4r4life ninjette.org newbie Name: Eric Location: Concord Join Date: Apr 2016 Motorcycle(s): 1999 Ninja 250 Posts: 4	07 Carb shenanigans So i just picked up a super cherry 07 with 600 miles on it, yes i know. bike has been sitting so i took the carb apart to clean it, cleaned the Main jet, pilot jet, fuel mixture port, choke port, main jet needle. i replaced the float needle and adjusted the float, bench sync the carbs, dipped the carb in chemtool, Blew b12 and compressed air through all the passage, you know, the whole works. But for some reason its doing some weird shenanigan. The bike when cold will not start, it sounds like it wants to idle but its so low rpm that it just stalls. Even with full choke it won't start, matter of fact when i do pull the choke once it gets going it actually kills the bike. i get the bike started with starting fluid and i let it warm up to working temp, idles perfect at 1300rpm, return to idle is perfect, rides perfect, no dead spot, lot of pull. so i thought hmm maybe the air cut off valve is killiing the bike, checked the air cut off diaphragm, looks brand new. The fuel screw is 2 turns out same as my other ninjas, ive worked on pre gen quiet a bit and im kinda lost right now, everything is super clean and all the rubber are in good shape. Hmmmm what can it be? Pic of bike for attention

August 30th, 2018, 06:29 AM	#6
Triple Jim Guy Who Enjoys Riding Name: Jim Location: North Carolina Join Date: Jul 2016 Motorcycle(s): Ninja 250 Posts: A lot. MOTM - Oct '18, Aug '17, Aug '16	I know you said 600 miles, but things can be deceptive. Are you sure the odometer is original, for example? Valves that are out of adjustment can cause your symptoms. On this engine, wear tends to cause the valve clearances to be reduced, and they eventually get to where they don't quite close when the engine is cold. This was the case when I got my '05, and I had similar hard starting and difficulty idling until it warmed up, at which time it ran fine. You can get a rough idea if this is the problem by doing a compression test on the cold engine, or you can just check the clearances. https://faq.ninja250.org/wiki/How_do..._the_valves%3F

September 10th, 2018, 04:32 PM	#7
T4r4life ninjette.org newbie Name: Eric Location: Concord Join Date: Apr 2016 Motorcycle(s): 1999 Ninja 250 Posts: 4	Good new everyone! i got the bike running smooth as butter now, the AF ratio screw for some reason are not the same on both side, when i turn the screw all the way in, one needle sticks out more than the other. so the first thing i did is order to the stage 1 jet kit and got rid of the small tiny jets these california bikes came with, and got a #40 idle, and #110 main. with new jets the bike runs a little better but still pretty bad, got the bike to operating temp with some starting fluid and started the carb sync, got the carb perfectly synced. it runs a little better, but again not perfect. rode it to my buddys house, and he tuned the AF screw on the bike with it running. He got a handy little tool that can adjust AF with the carb on the bike. man oh man is it good now, zero lag on throttle, perfect return to idle, perfect power. its just perfect. im stoked!

September 11th, 2018, 06:19 AM	#8
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	Good to hear you got it going. 110 is a pretty big Main Jet if you are running the stock airbox and exhaust. We ran a 108 with pods and a leaky exhaust. With 40 Pilots you should not be as far out on the idle mixture screws as you would with stock 38s, but it should end up providing the same mixture.