carb cleaning problem, not a novice!

revlis240 · April 25th, 2010, 07:09 PM

Hey guys,
Ive cleaned MANY ninja 250 carbs and ive never had a problem until now. With the last 2 bikes ive tried to clean, both of the bikes have been sitting for a year and they wouldnt even idle. One is a new gen body the other is an old gen body.

I took out the carbs, as usual, pulled the jets out (both idle and regular), cleaned out the jets, used the 2 nozzle areas to clean the inside of the carb, and made sure that the carb cleaner sprays out where its supposed to. then i reassembled, making sure that:

1) the boots were facing the right direction (head/carb)
2) the boots on both ends are snug and TIGHT

Now, both bikes turn on at full choke and idle. But the idle is erratic, it revs up, revs down. The biggest issue that under ANY throttle, it dies.

Have i missed a step here? I didnt touch the "top" of the carb, does the diaphram get stuck? they didnt seem stuck... Ive also checked for vacuum leaks. since the problem is apparent on BOTH bikes im trying to clean, i feel like ive missed a step or something?

Please help!!!

Abe

revlis240 · April 25th, 2010, 07:57 PM

hmm upon further reading it seems that i should have also cleaned the mixture screw and its passage. would not doing so cause these symptoms?

kkim · April 25th, 2010, 09:01 PM

Quote:

Originally Posted by revlis240

hmm upon further reading it seems that i should have also cleaned the mixture screw and its passage. would not doing so cause these symptoms?

if there is crap in the passage, it will. I usually remove all jets and blow out the passages with compressed air. Sometimes the smaller passages are so clogged/caked with varnish from dried up gas that it is impossible to clean the carb enough to be usable. Those are extreme cases, though. If stubborn, I have used carb soak that you buy in a gallon can to soak the carb overnight to hopefully loosen the stuck up gunk.

If I were you, if you are sure you have all the vacuum hoses hooked back up correctly, I'd redo the carbs and try blowing out the mixture screw passages with compressed air to see if you can clean them that way before soaking them.

When you are in there, double check the diaphragms for tears or holes.

GL

g21-30 · April 26th, 2010, 04:20 AM

If you're going to remove the carbs, in order to clean them, then you shouldn't take any shortcuts. Buy 2 rebuild kits (not sure of cost...maybe $10 ea) and a can of Gunk Carb Cleaner

Disassemble one carb at a time and place all parts in the Carb Cleaner basket and submerge the basket in the cleaner for the recommended time. Once clean, follow the cleaner instructions for final cleanup. Replace all gaskets and small parts included in the rebuild kit. Repeat for the 2nd carb.

The problem you're experiencing is the passage ways are not getting cleaned out sufficiently. While you have the carbs apart, you should also check the float levels.

Good Luck

NorCal_250R · April 26th, 2010, 10:34 PM

It is usually the pilot jets that plug the most.
Easiest answer is buy a jet kit from Factory Pro or Sportisi, then when you are in there, jet the carbs with the correct main jet for your application, get the needle height right, upgrade to 40 pilots, and set your fuel screws at 2.5 turns out...

If that doesn't work, then it is more likely something vacuum related, like a plugged charcoal canister or a vacuum line not fitted properly...

randomwalk101 · April 26th, 2010, 11:23 PM

jets are cheap..I would get 2 pilots and 2 main of your size then just swap them..then clean & recycle the old one for next time at your leasure....save a lot of down time.

g21-30 · April 27th, 2010, 03:59 AM

Neither Jordan's or John's suggestion addresses the float needle valve being gummed up.

If you don't want to disassemble the carbs, then at least fill them up with seafoam and let it sit overnight, before draining it out!

revlis240 · May 5th, 2010, 10:54 PM

OK im so frustrated!!!
I surgically disected the carb and cleaned it with Berrymans chem dip and that carb is CLEAN. Floats are functioning (imo) properly. i mean its beyond clean it looks brand new. However, the situation remains the exact same. I can get it to BARELY idle, but if you touch the gas it does. With full choke, it hunts between 5000 and 2500 rpm, it oscillates...

I mean this isnt rocket science, air fuel spark...

Air:
Filter looks brand new, no obstructions

Fuel:
Cleaned carb THROUGHLY. JETS ARE CLEAN!, made sure fuel is flowing, even checked little inline filter inside hose from gas tank, all clear

Spark:
Well it starts...so spark should be good right????

UUUUUUUUUUUUUUUUUUUUUUUUGH

Edit, upon further research i may need to change my plugs. I guess ill try that tomorrow

kkim · May 6th, 2010, 02:52 AM

Quote:

Originally Posted by revlis240

it hunts between 5000 and 2500 rpm, it oscillates...

that sounds like a possible vacuum leak.
also, what year is the bike/miles and when was the last valve adjustment?

Racer x · May 6th, 2010, 03:04 AM

I have found that bikes that sit need to have the pilot jetting drilled out of replaced. The jets seem to constrict .ether from the fuel or something in the fuel.

I work in a motorcycle dealer .If a bike that ran fine sits for a year.When I have to get it ready for sale.The thing I find VERY often is the pilot jets are closed . I don't mean clogged .I mean it is like the factory had never drilled them.

My advice is to run a reamer through the pilot jets .Or get a new #40 and try again.

HKr1 · May 6th, 2010, 05:29 AM

Quote:

Originally Posted by revlis240

it hunts between 5000 and 2500 rpm, it oscillates...

That sounds like CV carb lean surge.

revlis240 · May 6th, 2010, 11:28 AM

hrmm, both bikes have low miles. one has 1100 miles, the other has 5000 miles.

i can see light through the pin hole sized opening of the pilot jet. is that not enough? seems the same size as every other pilot jet ive ever seen. Is it possible it could be fouled plugs?

Racer x · May 6th, 2010, 02:27 PM

Yes it could be fouled plugs. I had a set of plugs give me a fit. The bike would not run .It was winter and I just installed big carbs so I figured it was just because it was winter.
Then when it warmed up it would not run and the bike always runs fine.

I pulled the plugs to check spark . First I held the plug on the side of the engine. and cranked the engine.The spark was not at the electrode. I could see th esparks down inside the insulator.

This is the odd part.When I ungrounded the side of the plug the spark moved to the tip.
I got another plug and it did not act that way, I put the new plug in and the bike ran fine.

Seeing light is good .I would still run a wire or a jet reamer through it just to scrape the hole clean.

revlis240 · May 6th, 2010, 06:14 PM

Thanks guys, I think i solved it. One down, one to go!
The problem was that although the carb was clean, the tank was a disaster. The gas had turned light brown, and there was all this crap in the tank. So i cleaned it out with acetone, ran some sea-foam through the tank and the first bike is running perfect again!!!

I will dip the second bike in the chem-dip and ream the jets again. I hope that will have the same results!!

EDIT: The second bike is all up and running as well! One of the float needles was stuck, preventing fuel from entering that carb!!!!

g21-30 · May 7th, 2010, 05:02 AM

Quote:

Originally Posted by revlis240

EDIT: The second bike is all up and running as well! One of the float needles was stuck, preventing fuel from entering that carb!!!!

Congrats! Lots of people forget about the float needle. Out of site, out of .....!

NorCal_250R · May 8th, 2010, 08:10 PM

Glad to hear everything is working. This bike is very tempermental when it is stored. You need to keep the battery charged, the fuel fresh, the carbs clean, the bike turned over and running on a very regular basis...it will save a bunch of headaches later...

April 25th, 2010, 07:09 PM	#1
revlis240 ninjette.org newbie Name: Abe Location: Los Angeles Join Date: Apr 2010 Motorcycle(s): Buncha ninjas Posts: 5	carb cleaning problem, not a novice! Hey guys, Ive cleaned MANY ninja 250 carbs and ive never had a problem until now. With the last 2 bikes ive tried to clean, both of the bikes have been sitting for a year and they wouldnt even idle. One is a new gen body the other is an old gen body. I took out the carbs, as usual, pulled the jets out (both idle and regular), cleaned out the jets, used the 2 nozzle areas to clean the inside of the carb, and made sure that the carb cleaner sprays out where its supposed to. then i reassembled, making sure that: 1) the boots were facing the right direction (head/carb) 2) the boots on both ends are snug and TIGHT Now, both bikes turn on at full choke and idle. But the idle is erratic, it revs up, revs down. The biggest issue that under ANY throttle, it dies. Have i missed a step here? I didnt touch the "top" of the carb, does the diaphram get stuck? they didnt seem stuck... Ive also checked for vacuum leaks. since the problem is apparent on BOTH bikes im trying to clean, i feel like ive missed a step or something? Please help!!! Abe

May 6th, 2010, 06:14 PM	#14
revlis240 ninjette.org newbie Name: Abe Location: Los Angeles Join Date: Apr 2010 Motorcycle(s): Buncha ninjas Posts: 5	Thanks guys, I think i solved it. One down, one to go! The problem was that although the carb was clean, the tank was a disaster. The gas had turned light brown, and there was all this crap in the tank. So i cleaned it out with acetone, ran some sea-foam through the tank and the first bike is running perfect again!!! I will dip the second bike in the chem-dip and ream the jets again. I hope that will have the same results!! EDIT: The second bike is all up and running as well! One of the float needles was stuck, preventing fuel from entering that carb!!!! Last futzed with by revlis240; May 6th, 2010 at 08:21 PM.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Carb cleaning QUESTION	ortizj2289	2008 - 2012 Ninja 250R Tech Talk	17	April 3rd, 2015 01:19 PM
First Carb Cleaning	Achilles	2008 - 2012 Ninja 250R Tech Talk	33	February 1st, 2013 11:48 PM
Seafoam for carb cleaning?	chadh92	1986 - 2007 Ninja 250R Tech Talk	21	December 26th, 2012 05:31 PM
Carb Cleaning/Rebuilding Question....	jboyd12	2008 - 2012 Ninja 250R Tech Talk	13	March 26th, 2012 08:58 PM
Carb Cleaning??	jboyd12	General Motorcycling Discussion	11	March 3rd, 2012 10:05 AM

April 25th, 2010, 07:57 PM	#2
revlis240 ninjette.org newbie Name: Abe Location: Los Angeles Join Date: Apr 2010 Motorcycle(s): Buncha ninjas Posts: 5	hmm upon further reading it seems that i should have also cleaned the mixture screw and its passage. would not doing so cause these symptoms?

April 26th, 2010, 04:20 AM	#4
g21-30 ninjette.org certified postwhore Name: Sam Location: Northern Virginia Join Date: Nov 2008 Motorcycle(s): Ninja 250R 2009 and ZX-12R 2000 Posts: A lot.	If you're going to remove the carbs, in order to clean them, then you shouldn't take any shortcuts. Buy 2 rebuild kits (not sure of cost...maybe $10 ea) and a can of Gunk Carb Cleaner Disassemble one carb at a time and place all parts in the Carb Cleaner basket and submerge the basket in the cleaner for the recommended time. Once clean, follow the cleaner instructions for final cleanup. Replace all gaskets and small parts included in the rebuild kit. Repeat for the 2nd carb. The problem you're experiencing is the passage ways are not getting cleaned out sufficiently. While you have the carbs apart, you should also check the float levels. Good Luck

April 26th, 2010, 10:34 PM	#5
NorCal_250R ninjette.org member Name: Jordan Location: Corte Madera Join Date: Jun 2009 Motorcycle(s): 06 Ninja 650R, 08 Ninja 250R, 00 Aprilia SR50 (dead) Posts: 94	It is usually the pilot jets that plug the most. Easiest answer is buy a jet kit from Factory Pro or Sportisi, then when you are in there, jet the carbs with the correct main jet for your application, get the needle height right, upgrade to 40 pilots, and set your fuel screws at 2.5 turns out... If that doesn't work, then it is more likely something vacuum related, like a plugged charcoal canister or a vacuum line not fitted properly...

April 26th, 2010, 11:23 PM	#6
randomwalk101 self wrencher Name: john Location: houston Join Date: Dec 2008 Motorcycle(s): 08 250r and 07 600r Posts: A lot.	jets are cheap..I would get 2 pilots and 2 main of your size then just swap them..then clean & recycle the old one for next time at your leasure....save a lot of down time.

April 27th, 2010, 03:59 AM	#7
g21-30 ninjette.org certified postwhore Name: Sam Location: Northern Virginia Join Date: Nov 2008 Motorcycle(s): Ninja 250R 2009 and ZX-12R 2000 Posts: A lot.	Neither Jordan's or John's suggestion addresses the float needle valve being gummed up. If you don't want to disassemble the carbs, then at least fill them up with seafoam and let it sit overnight, before draining it out!

May 5th, 2010, 10:54 PM	#8
revlis240 ninjette.org newbie Name: Abe Location: Los Angeles Join Date: Apr 2010 Motorcycle(s): Buncha ninjas Posts: 5	OK im so frustrated!!! I surgically disected the carb and cleaned it with Berrymans chem dip and that carb is CLEAN. Floats are functioning (imo) properly. i mean its beyond clean it looks brand new. However, the situation remains the exact same. I can get it to BARELY idle, but if you touch the gas it does. With full choke, it hunts between 5000 and 2500 rpm, it oscillates... I mean this isnt rocket science, air fuel spark... Air: Filter looks brand new, no obstructions Fuel: Cleaned carb THROUGHLY. JETS ARE CLEAN!, made sure fuel is flowing, even checked little inline filter inside hose from gas tank, all clear Spark: Well it starts...so spark should be good right???? UUUUUUUUUUUUUUUUUUUUUUUUGH Edit, upon further research i may need to change my plugs. I guess ill try that tomorrow

May 6th, 2010, 03:04 AM	#10
Racer x ninjette.org certified postwhore Name: Eric Location: Iowa City Join Date: May 2009 Motorcycle(s): 2008 Kawmeracchi 350 2010 Project X Posts: A lot. Blog Entries: 54 MOTM - Sep '18, Feb '16	I have found that bikes that sit need to have the pilot jetting drilled out of replaced. The jets seem to constrict .ether from the fuel or something in the fuel. I work in a motorcycle dealer .If a bike that ran fine sits for a year.When I have to get it ready for sale.The thing I find VERY often is the pilot jets are closed . I don't mean clogged .I mean it is like the factory had never drilled them. My advice is to run a reamer through the pilot jets .Or get a new #40 and try again.

May 6th, 2010, 11:28 AM	#12
revlis240 ninjette.org newbie Name: Abe Location: Los Angeles Join Date: Apr 2010 Motorcycle(s): Buncha ninjas Posts: 5	hrmm, both bikes have low miles. one has 1100 miles, the other has 5000 miles. i can see light through the pin hole sized opening of the pilot jet. is that not enough? seems the same size as every other pilot jet ive ever seen. Is it possible it could be fouled plugs?

May 6th, 2010, 02:27 PM	#13
Racer x ninjette.org certified postwhore Name: Eric Location: Iowa City Join Date: May 2009 Motorcycle(s): 2008 Kawmeracchi 350 2010 Project X Posts: A lot. Blog Entries: 54 MOTM - Sep '18, Feb '16	Yes it could be fouled plugs. I had a set of plugs give me a fit. The bike would not run .It was winter and I just installed big carbs so I figured it was just because it was winter. Then when it warmed up it would not run and the bike always runs fine. I pulled the plugs to check spark . First I held the plug on the side of the engine. and cranked the engine.The spark was not at the electrode. I could see th esparks down inside the insulator. This is the odd part.When I ungrounded the side of the plug the spark moved to the tip. I got another plug and it did not act that way, I put the new plug in and the bike ran fine. Seeing light is good .I would still run a wire or a jet reamer through it just to scrape the hole clean.

May 8th, 2010, 08:10 PM	#16
NorCal_250R ninjette.org member Name: Jordan Location: Corte Madera Join Date: Jun 2009 Motorcycle(s): 06 Ninja 650R, 08 Ninja 250R, 00 Aprilia SR50 (dead) Posts: 94	Glad to hear everything is working. This bike is very tempermental when it is stored. You need to keep the battery charged, the fuel fresh, the carbs clean, the bike turned over and running on a very regular basis...it will save a bunch of headaches later...