Problems starting engine

Slono · March 29th, 2012, 10:01 PM

I've recently installed an Area P exhaust and rejetted my bike. Its been running well for a couple days, and I've ridden 300 km since all the installations with no problems until today. I stopped by a gas station to fill up, and when I tried to start it, it wouldn't turn over. For some reason the water temperature warning light seemed to be on, and although its apparently supposed to go on before you start the engine and go off after starting the engine, I've never noticed it to be on at all.

Anyway, I had to turn the throttle while holding down the ignition switch to successfully start the bike. It also backfired while it started up and it startled people nearby.

The oil level looks fine (mid-level) when I checked. What's the problem? This has never happened to me before and I have 7600 kms logged on my odometer.

KELPHYN · March 29th, 2012, 10:20 PM

First, bike won't turn over at first. Probably bike in gear, sidestand down, clutch not pulled in. As for needing a little throttle, sometimes needs it if bike is hot.(the joys of carburetors) And the backfire happens sometimes. Mine did it with the stock pipe and still the odd time with the aftermarket pipe.

Motofool · March 30th, 2012, 07:23 AM

Lean mixtures cause faster burning and rich mixtures cause slower burning.

Backfires happen when the mix is rich and explosion happens in a retarded way, while the exhaust valves are opening.

My guess is that the level in the bowls increased while you were filling up.

Check that your petcock is really vacuum activated.

Just preventing any water or contamination in the new fuel from going down into the carbs, I have made a habit of closing the petcock while fueling (mine leaks down with or without vacuum).

Spark plugs that miss firing intermittently can also cause backfiring.

Slono · March 30th, 2012, 08:46 AM

As much as I'd like to think the side stand was down and clutch wasn't squeezed, they both definitely were. I parked my bike in neutral and filled my tank up while sitting on it so the side stand was never down. I also had the choke fully on.

How do you check if the petcock is vacuumed? Just out your hand on the spout?

Motofool · March 30th, 2012, 11:09 AM

With the engine off, just disconnect the hose at the carb nipple and place the end into a glass container from which you can return the fuel to the tank.
Then open the petcock.
If gas flows into the container with the engine off (no vacuum reaching the petcock via the other hose), the petcock is not working properly.

In such a case, you need to be careful not to leave the petcock in open or reserve positions while the engine is not working, because the carbs' bowls could get overflown.

Check all your spark plug and ignition coils anyway, just in case the backfire was electrical related.

KELPHYN · March 31st, 2012, 12:39 AM

Okay, when you said "wouldn't turn over" did you mean bike wouldn't crank or would crank but not start? Cause you say that you had to give it throttle to start, has nothing to do with the bike turning over. Now if the bike was just not starting(firing) but turning over and you had the choke on. It more than likely slightly flooded the engine and when you give it a little throttle, you in a sense supply more air leaning out the mixture and the bike fired. Some of the over rich mixture would had gathered in your exhaust and ignited when your bike started causing the AFTERfire,(a backfire is when it fires back through the carbs)

When was the last time you cleaned your air filter? Did you remove your snorkel when you did pipe and rejet? A little extra air flow might help your starting if you didn't.

Slono · March 31st, 2012, 06:13 AM

Sorry, I guess I told you guys incorrectly. The bike cranks but it had a really hard time starting even with the choke. Before I pulled into the gas station I was on the freeway for approximately 35 minutes too so it wasn't like I was starting the bike in a cold state.

The last time I cleaned my carbs was recently with sea foam. I also changed the oil yesterday and ran it a bit. It seemed fine and I had no problems with it. Do you think my bike overheated while traveling at high speeds?

Motofool · March 31st, 2012, 08:38 AM

When the engine has been running and is hot, use of choke is not only unnecessary but counter-productive.

You are making the mix over-rich and complicating things, like splashing raw fuel over the electrodes of the spark plugs and reducing the temperature in the chamber.

Most of the bikes need the throttle to be cracked open to re-start from hot conditions.

There is no reason to think of overheating in your case.

March 29th, 2012, 10:01 PM	#1
Slono ninjette.org guru Name: Solon Location: Toronto, Ontario Join Date: Jun 2011 Motorcycle(s): 2011 Kawasaki Ninja 250R (sold), 2007 SV650s (deer wrecked), 2010 Suzuki SV650S Posts: 334	Problems starting engine I've recently installed an Area P exhaust and rejetted my bike. Its been running well for a couple days, and I've ridden 300 km since all the installations with no problems until today. I stopped by a gas station to fill up, and when I tried to start it, it wouldn't turn over. For some reason the water temperature warning light seemed to be on, and although its apparently supposed to go on before you start the engine and go off after starting the engine, I've never noticed it to be on at all. Anyway, I had to turn the throttle while holding down the ignition switch to successfully start the bike. It also backfired while it started up and it startled people nearby. The oil level looks fine (mid-level) when I checked. What's the problem? This has never happened to me before and I have 7600 kms logged on my odometer.

March 30th, 2012, 07:23 AM	#3
Motofool Daily Ninjette rider Name: Hernan Location: Florida Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250 Posts: A lot. MOTY - 2016, MOTM - Dec '12, Jan '14, Jan '15, May '16	Lean mixtures cause faster burning and rich mixtures cause slower burning. Backfires happen when the mix is rich and explosion happens in a retarded way, while the exhaust valves are opening. My guess is that the level in the bowls increased while you were filling up. Check that your petcock is really vacuum activated. Just preventing any water or contamination in the new fuel from going down into the carbs, I have made a habit of closing the petcock while fueling (mine leaks down with or without vacuum). Spark plugs that miss firing intermittently can also cause backfiring. __________________________________________________ *Motofool* *.................................Never ride faster than your guardian angel can fly* "Mankind is composed of two sorts of men — those who love and create, and those who hate and destroy. Love is the bond between men, the way to teach and the center of the world." - José Martí

March 30th, 2012, 11:09 AM	#5
Motofool Daily Ninjette rider Name: Hernan Location: Florida Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250 Posts: A lot. MOTY - 2016, MOTM - Dec '12, Jan '14, Jan '15, May '16	With the engine off, just disconnect the hose at the carb nipple and place the end into a glass container from which you can return the fuel to the tank. Then open the petcock. If gas flows into the container with the engine off (no vacuum reaching the petcock via the other hose), the petcock is not working properly. In such a case, you need to be careful not to leave the petcock in open or reserve positions while the engine is not working, because the carbs' bowls could get overflown. Check all your spark plug and ignition coils anyway, just in case the backfire was electrical related. __________________________________________________ *Motofool* *.................................Never ride faster than your guardian angel can fly* "Mankind is composed of two sorts of men — those who love and create, and those who hate and destroy. Love is the bond between men, the way to teach and the center of the world." - José Martí

March 31st, 2012, 08:38 AM	#8
Motofool Daily Ninjette rider Name: Hernan Location: Florida Join Date: Mar 2011 Motorcycle(s): 2007 Ninja 250 Posts: A lot. MOTY - 2016, MOTM - Dec '12, Jan '14, Jan '15, May '16	When the engine has been running and is hot, use of choke is not only unnecessary but counter-productive. You are making the mix over-rich and complicating things, like splashing raw fuel over the electrodes of the spark plugs and reducing the temperature in the chamber. Most of the bikes need the throttle to be cracked open to re-start from hot conditions. There is no reason to think of overheating in your case. __________________________________________________ *Motofool* *.................................Never ride faster than your guardian angel can fly* "Mankind is composed of two sorts of men — those who love and create, and those who hate and destroy. Love is the bond between men, the way to teach and the center of the world." - José Martí

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Starting and riding on cold engine	itslocfoo	1986 - 2007 Ninja 250R Tech Talk	7	December 10th, 2013 05:51 PM
Engine turning over but not starting	swede core	1986 - 2007 Ninja 250R Tech Talk	4	April 8th, 2013 10:53 AM
starting problems	deanomyte	1986 - 2007 Ninja 250R Tech Talk	7	November 5th, 2012 06:59 PM
starting problems	dago	1986 - 2007 Ninja 250R Tech Talk	21	March 17th, 2012 01:50 PM
Problems Starting running a bike	danius	2008 - 2012 Ninja 250R Tech Talk	0	October 28th, 2010 05:39 AM

March 29th, 2012, 10:20 PM	#2
KELPHYN ninjette.org guru Name: Calvin Location: Quesnel, B.C Join Date: Aug 2009 Motorcycle(s): '08 250R (sold), 2013 300SE Posts: 276	First, bike won't turn over at first. Probably bike in gear, sidestand down, clutch not pulled in. As for needing a little throttle, sometimes needs it if bike is hot.(the joys of carburetors) And the backfire happens sometimes. Mine did it with the stock pipe and still the odd time with the aftermarket pipe.

March 30th, 2012, 08:46 AM	#4
Slono ninjette.org guru Name: Solon Location: Toronto, Ontario Join Date: Jun 2011 Motorcycle(s): 2011 Kawasaki Ninja 250R (sold), 2007 SV650s (deer wrecked), 2010 Suzuki SV650S Posts: 334	As much as I'd like to think the side stand was down and clutch wasn't squeezed, they both definitely were. I parked my bike in neutral and filled my tank up while sitting on it so the side stand was never down. I also had the choke fully on. How do you check if the petcock is vacuumed? Just out your hand on the spout?

March 31st, 2012, 12:39 AM	#6
KELPHYN ninjette.org guru Name: Calvin Location: Quesnel, B.C Join Date: Aug 2009 Motorcycle(s): '08 250R (sold), 2013 300SE Posts: 276	Okay, when you said "wouldn't turn over" did you mean bike wouldn't crank or would crank but not start? Cause you say that you had to give it throttle to start, has nothing to do with the bike turning over. Now if the bike was just not starting(firing) but turning over and you had the choke on. It more than likely slightly flooded the engine and when you give it a little throttle, you in a sense supply more air leaning out the mixture and the bike fired. Some of the over rich mixture would had gathered in your exhaust and ignited when your bike started causing the AFTERfire,(a backfire is when it fires back through the carbs) When was the last time you cleaned your air filter? Did you remove your snorkel when you did pipe and rejet? A little extra air flow might help your starting if you didn't.

March 31st, 2012, 06:13 AM	#7
Slono ninjette.org guru Name: Solon Location: Toronto, Ontario Join Date: Jun 2011 Motorcycle(s): 2011 Kawasaki Ninja 250R (sold), 2007 SV650s (deer wrecked), 2010 Suzuki SV650S Posts: 334	Sorry, I guess I told you guys incorrectly. The bike cranks but it had a really hard time starting even with the choke. Before I pulled into the gas station I was on the freeway for approximately 35 minutes too so it wasn't like I was starting the bike in a cold state. The last time I cleaned my carbs was recently with sea foam. I also changed the oil yesterday and ran it a bit. It seemed fine and I had no problems with it. Do you think my bike overheated while traveling at high speeds?