Bike Hesitates to Start Without Throttle Input

[ninjayetti]

Hi All,

Some background. Have a 2012 (11k miles). It sat in a garage for about 2 years with stabil in it, and was started once every two weeks, for the most part, but towards the end of that stint, not at all.

It was just delivered to my new residence, and did not want to start. It turned over, but nothing. I finally got it started after a few minutes with a lot of throttle input.

Of course, it ran like crap, so I added sea foam and it has run great since then. It also idles just fine once it warms up. I've put in about 150 miles with good performance.

However, if I've not ridden for a day, it will not fire up without a lot of throttle input, even with full choke.

Again, once it warms up, it runs just fine. No issues at all.

Also, if I've been riding and then stop for gas, it fires right back up as long as it's warm.

So, I'm wondering, is this:

A) Battery issue? Doesn't seem like it since it starts when I use throttle, so it seems more like a

B) Fueling Issues

C) Carb issue?

Any insight greatly appreciated.

Thanks!

[csmith12]

Welcome Ryan!

Hard cold starting, but easy warm starting can be many things but here are a few ideas.

idle rpms out of adjustment
idle circuit needs cleaning
idle mix screws out of adjustment
airbox/snorkle obstructions
poor gas quality/contaminated
values need to be adjusted
improper jetting

Any mods to the bike? Exhaust or airbox?

[ninjayetti]

Originally Posted by csmith12

Welcome Ryan!

Hard cold starting, but easy warm starting can be many things but here are a few ideas.

idle rpms out of adjustment
idle circuit needs cleaning
idle mix screws out of adjustment
airbox/snorkle obstructions
poor gas quality/contaminated
values need to be adjusted
improper jetting

Any mods to the bike? Exhaust or airbox?

Thank you for your response. Yes, I realize I should have included this.

I added a Leo Vince slip-on. When I lived in AZ, I did not have any issues. The bike always started just fine.

I then moved to PA and the bike rode terribly. Bogged down and felt as if I was running at least 30% under power. And it ran very, very hot.

So, naturally, I thought I definitely needed a rejet. But, I was no longer able to ride, so the bike just sat.

Then I moved to NC, and I have not any of those issues. Now I just have a hard time getting her started.

I got the valves checked at 10k miles, and they said there were in spec. Now, whether or not they actually did the requested work is another question, but I used them often and they seemed honest.

Pretty sure I've run all of the stale gas out of the tank in the last 150 or so miles.

I will search for threads related to the other issues you mentioned.

Thank you again!

Ryan

[csmith12]

I would pop out a plug and check the color, sounds kinda lean. Even though a slip on doesn't require a full rejet (a couple of shims normally do just fine), it doesn't hurt to check and only takes a couple of minutes. Whitish color = lean, blackish color = okish to rich, you're looking for a nice really, really dark brown.

Check that snorkle area first and make sure it's clean and clear. After 2yrs of sitting, you may have a nice clog in there.

[ninjayetti]

Originally Posted by csmith12

I would pop out a plug and check the color, sounds kinda lean. Even though a slip on doesn't require a full rejet (a couple of shims normally do just fine), it doesn't hurt to check and only takes a couple of minutes. Whitish color = lean, blackish color = okish to rich, you're looking for a nice really, really dark brown.

Check that snorkle area first and make sure it's clean and clear. After 2yrs of sitting, you may have a nice clog in there.

I checked the snorkle area. No obstructions.

Here are some pictures of one of the plugs:

http://imgur.com/a/K9gT9

[Motofool]

Originally Posted by ninjayetti

I checked the snorkle area. No obstructions.

Here are some pictures of one of the plugs:

http://imgur.com/a/K9gT9

Welcome, Ryan !!!

The gap of the last picture is excessive.

Here is a guide:

http://www.dansmc.com/sparkplugs1.htm

http://www.dansmc.com/spark_plugs/sp...s_catalog.html

[jkv45]

The last photo of the plug looks like it wasn't fully tightened down.

I would completely drain the tank to remove any condensation build-up that may have accumulated. Condensation/water is not going anywhere unless you run the tank dry, so it's best to just drain it. I'd also drain the floatbowls and look at what comes out.

Have you tried backing the choke off some while cranking? It could be that it's getting more fuel from the enrichener (choke) than it needs. Needing to open the throttle to get it to start could mean it needs more air. Air filter is in good shape?

I'd confirm that you have a good battery. You should see 12.7V or more after sitting at least a few hours. A low battery can give you odd problems as well.

Is it dripping anything? If it were dripping gas from the carbs the fuel level in the bowls may be too low until you have done some cranking to build vacuum to the petcock and start fuel flowing.

[ninjayetti]

Originally Posted by Motofool

Welcome, Ryan !!!

The gap of the last picture is excessive.

Here is a guide:

http://www.dansmc.com/sparkplugs1.htm

http://www.dansmc.com/spark_plugs/sp...s_catalog.html

Hi,

Thanks for the reply. Not certain I follow. You're saying I may have too hot of a plug in there?

I think I'm just going to replace both for good measure.

[ninjayetti]

Originally Posted by jkv45

The last photo of the plug looks like it wasn't fully tightened down.

It was pretty darn tight.

Originally Posted by jkv45

I would completely drain the tank to remove any condensation build-up that may have accumulated. Condensation/water is not going anywhere unless you run the tank dry, so it's best to just drain it. I'd also drain the floatbowls and look at what comes out.

Okay, I will take a look in the DIY. Never done this before, but it's time to learn!

Originally Posted by jkv45

Have you tried backing the choke off some while cranking? It could be that it's getting more fuel from the enrichener (choke) than it needs. Needing to open the throttle to get it to start could mean it needs more air. Air filter is in good shape?

I cleaned the air filter when I was checking to make sure the snorkel wasn't clogged. It is in fine condition.

I did start the bike without the filter in, momentarily, and it did seem to start up with more ease.

Originally Posted by jkv45

I'd confirm that you have a good battery. You should see 12.7V or more after sitting at least a few hours. A low battery can give you odd problems as well.

Yes, I planned on doing this. I wouldn't be surprised that it's low since it was sitting for so long.

Originally Posted by jkv45

Is it dripping anything? If it were dripping gas from the carbs the fuel level in the bowls may be too low until you have done some cranking to build vacuum to the petcock and start fuel flowing.

No, it is not dripping anything.

I will look into all of this.

Thanks for your reply!

[jkv45]

Did you oil the filter after you cleaned it? Too much oil can reduce the airflow to the point that it causes running problems.

If it starts better without a filter it's telling you it isn't getting enough air, or too much fuel, with the filter in place.

This section has some info on draining the tank and carbs, plus a lot more - http://faq.ninja250.org/wiki/Intake

[ninjayetti]

Originally Posted by jkv45

Did you oil the filter after you cleaned it? Too much oil can reduce the airflow to the point that it causes running problems.

If it starts better without a filter it's telling you it isn't getting enough air, or too much fuel, with the filter in place.

This section has some info on draining the tank and carbs, plus a lot more - http://faq.ninja250.org/wiki/Intake

No, I did not oil it. There was still a good amount left- but by no means excessive at all.

So, it sounds as if it's not getting enough air. What are the main culprits, if that's the case?

Great, I'll take a look at those resources. Thank you!

[jkv45]

Originally Posted by ninjayetti

No, I did not oil it. There was still a good amount left- but by no means excessive at all.

So, it sounds as if it's not getting enough air. What are the main culprits, if that's the case?

Great, I'll take a look at those resources. Thank you!

I would say too much choke/enrichener. Drawing-in condensation from the tank, or bad fuel, can also give you starting problems.

What gas are you using? How old is it? High octane gas can make starting more difficult. Gas with ethanol doesn't last as long as gas without, and can collect excess water even at the station.

[Motofool]

Originally Posted by ninjayetti

Hi,

Thanks for the reply. Not certain I follow. You're saying I may have too hot of a plug in there?

I think I'm just going to replace both for good measure.

I meant the distance between the electrodes: if too big, the sparks cannot jump.
If you are installing new plugs, there is no need to worry about that: they come properly calibrated, regarding that distance.

That plug has been burning a reach mix (maybe too high fuel level inside that carb's bowl or air restrictions or stuck-open choke) or not firing at all.
The plug of the first pictures looks like it has been burning a lean mix (maybe clogged jets o damaged rubber diaphragm).

I agree with jkv45's posts above.
It will eventually start up, but several things must be OK:
- High voltage to each plug (hence, the need of a battery with abundant juice to crank for many minutes).
- Enough air.
- Enough fuel, but not too much (petcock, vacuum, filters, floats level.
- Enough compression (good rings and valves that completely seat and seal at the proper times).

[ninjayetti]

Originally Posted by jkv45

I would say too much choke/enrichener. Drawing-in condensation from the tank, or bad fuel, can also give you starting problems.

What gas are you using? How old is it? High octane gas can make starting more difficult. Gas with ethanol doesn't last as long as gas without, and can collect excess water even at the station.

When the bike was shipped to me, it had about a quart of a tank left that was probably sitting for 2 years (stabil was added). I didn't drain it, unfortunately. Instead, I just filled it up with fresh gas, 87 octane, and added sea foam.

[ninjayetti]

Originally Posted by Motofool

I meant the distance between the electrodes: if too big, the sparks cannot jump.
If you are installing new plugs, there is no need to worry about that: they come properly calibrated, regarding that distance.

That plug has been burning a reach mix (maybe too high fuel level inside that carb's bowl or air restrictions or stuck-open choke) or not firing at all.
The plug of the first pictures looks like it has been burning a lean mix (maybe clogged jets o damaged rubber diaphragm).

I agree with jkv45's posts above.
It will eventually start up, but several things must be OK:
- High voltage to each plug (hence, the need of a battery with abundant juice to crank for many minutes).
- Enough air.
- Enough fuel, but not too much (petcock, vacuum, filters, floats level.
- Enough compression (good rings and valves that completely seat and seal at the proper times).

Thanks for your response. I have new plugs coming, so I'm going to install those to see if that may be the issue. If not , I'm going to then check the battery and, ultimately, drain the tank and clean the carbs.

[HoneyBadgerRy]

Originally Posted by ninjayetti

Thanks for your response. I have new plugs coming, so I'm going to install those to see if that may be the issue. If not , I'm going to then check the battery and, ultimately, drain the tank and clean the carbs.

Instead of just measuring the battery, try to jump it with a car battery while the car is off. That is the best way to assure that the battery is not the culprit.

[ninjayetti]

Originally Posted by HoneyBadgerRy

Instead of just measuring the battery, try to jump it with a car battery while the car is off. That is the best way to assure that the battery is not the culprit.

Makes sense. Thank you!

[jkv45]

Originally Posted by ninjayetti

When the bike was shipped to me, it had about a quart of a tank left that was probably sitting for 2 years (stabil was added). I didn't drain it, unfortunately. Instead, I just filled it up with fresh gas, 87 octane, and added sea foam.

I would completely drain it before moving on.

No matter what you do, it's not going to run right with bad gas. Adding fresh to old gas and a fuel system cleaner isn't going to do it. I've used year old gas that was stabilized, and it worked ok, but if you are troubleshooting it's not worth risking.

Because the tank was low, condensation is also a concern.

[ninjayetti]

Originally Posted by jkv45

I would completely drain it before moving on.

No matter what you do, it's not going to run right with bad gas. Adding fresh to old gas and a fuel system cleaner isn't going to do it. I've used year old gas that was stabilized, and it worked ok, but if you are troubleshooting it's not worth risking.

Because the tank was low, condensation is also a concern.

Question: If I've ridden the bike enough, wouldn't the bad gas technically have cycled through the bike, leaving only good gas?

[ninjayetti]

Quick question: how much fuel is typically in the bowls? I went to drain them to see the quality of gas, and it's fine, but I feel like i've drained at least 12oz, and there is no sign of it stopping.

[jkv45]

Originally Posted by ninjayetti

Question: If I've ridden the bike enough, wouldn't the bad gas technically have cycled through the bike, leaving only good gas?

What can happen is condensation will settle to the bottom of the tank, and occasionally get drawn up as the gas sloshes around in the tank. Running low, or on reserve, will most certainly let it into the carbs. Bad gas, mixed with good gas, is still bad gas.

It's just the safest first step, if you think the gas may be in question, to remove all of it before getting too carried away.

[jkv45]

Originally Posted by ninjayetti

Quick question: how much fuel is typically in the bowls? I went to drain them to see the quality of gas, and it's fine, but I feel like i've drained at least 12oz, and there is no sign of it stopping.

Then there's a problem. You should't get that much, and it should stop.

That would suggest the petcock is not shutting off fuel flow like it should when the engine is off (no vacuum to the petcock).

[ninjayetti]

Originally Posted by jkv45

Then there's a problem. You should't get that much, and it should stop.

That would suggest the petcock is not shutting off fuel flow like it should when the engine is off (no vacuum to the petcock).

Okay, glad we're getting somewhere. If there's no vacuum, does that suggest a hose is loose somewhere?

Forgive my ignorance, this is the first time I've ever worked on anything mechanical in my entire life.

EDIT: CHECKED HOSE FROM PETCOCK TO CARB. CONNECTION IS GOOD. HOSE IS IN GOOD CONDITION.

Edit. good video on refurbing petcock:

https://www.youtube.com/watch?v=5DqvB_5gP20

EDIT:

I took the big hose off the petcock. Fuel flowed freely and quickly. Looks like this baby is bad.

[jkv45]

Originally Posted by ninjayetti

I took the big hose off the petcock. Fuel flowed freely and quickly. Looks like this baby is bad.

Yup. Should not flow without vacuum unless the petcock is set to "Prime" - but I don't think the NewGen has that (someone please correct me if I'm wrong).

[ninjayetti]

Originally Posted by jkv45

Yup. Should not flow without vacuum unless the petcock is set to "Prime" - but I don't think the NewGen has that (someone please correct me if I'm wrong).

It has on and prime.

Thanks for your help! Now just a matter of finding an affordable kit.

[HoneyBadgerRy]

Originally Posted by jkv45

Yup. Should not flow without vacuum unless the petcock is set to "Prime" - but I don't think the NewGen has that (someone please correct me if I'm wrong).

Idk if the newgen does, but the pregen doesn't, and I sure wish it did.

[ninjayetti]

Anyone know where I can find newgen kits? All I can find is this on amazon, but it's pregen:

http://www.amazon.com/gp/product/B00..._U1CGub05DT5NT

[ninjayetti]

Hi Guys,

First, want to thank you for your help thus far.

Given that there is too much fuel and not enough air in the bowl as a result of the faulty petcock, would this contribute to the fouling of spark plugs?

Also, I'm assuming the fault petcock will only really affect starting conditions, correct? Once started, and the vacuum is strong, does the petcock essentially operate correctly, since the bowls will close when full, or will it still foul A/F equilibrium?



Thanks!

[HoneyBadgerRy]

Originally Posted by ninjayetti

Hi Guys,

First, want to thank you for your help thus far.

Given that there is too much fuel and not enough air in the bowl as a result of the faulty petcock, would this contribute to the fouling of spark plugs?

Also, I'm assuming the fault petcock will only really affect starting conditions, correct? Once started, and the vacuum is strong, does the petcock essentially operate correctly, since the bowls will close when full, or will it still foul A/F equilibrium?



Thanks!

The vacuum simply tells the petcock to allow fuel to enter the carbs. When the bike is running the petcock should be on, and when the bike is not running the petcock should be off. Your petcock is always stuck on on.

That isn't your only problem. With your floats set properly and your float needles in good shape your carbs would be set at the proper level and it wouldn't matter if the petcock was always on or not, however there is a problem, and you need to solve it, fixing the petcock is a nice safety feature, but its not neccescary.

MX bikes don't have vacuum operated petcocks, so you have to turn the petcocks off when the bike is off (or else you risk hydrolock when your floats go bad), street bikes have vacuum petcocks so that you don't have to turn the petcock off.

[ninjayetti]

Originally Posted by HoneyBadgerRy

The vacuum simply tells the petcock to allow fuel to enter the carbs. When the bike is running the petcock should be on, and when the bike is not running the petcock should be off. Your petcock is always stuck on on.

That isn't your only problem. With your floats set properly and your float needles in good shape your carbs would be set at the proper level and it wouldn't matter if the petcock was always on or not, however there is a problem, and you need to solve it, fixing the petcock is a nice safety feature, but its not neccescary.

MX bikes don't have vacuum operated petcocks, so you have to turn the petcocks off when the bike is off (or else you risk hydrolock when your floats go bad), street bikes have vacuum petcocks so that you don't have to turn the petcock off.

So, the petcock does need to be fixed, but I also need to troubleshoot the carbs themselves; most notably,float needles and floats?

[HoneyBadgerRy]

Originally Posted by ninjayetti

So, the petcock does need to be fixed, but I also need to troubleshoot the carbs themselves; most notably,float needles and floats?

Yes. You need to set your float height and replace your float seals. You should rebuild/replace your petcock, but it is not neccesacry to make your bike run.

[ninjayetti]

Originally Posted by HoneyBadgerRy

Yes. You need to set your float height and replace your float seals. You should rebuild/replace your petcock, but it is not neccesacry to make your bike run.

Thanks for the clarification.

I already purchased the petcock kit.

This is going to start getting expensive.

To be clear, the bike runs and idles just fine once warm. With that being said, I'm still not sure if it's running too lean, but that might be the case if the bowls need adjustment, correct?

Thanks again!

Ryan

[HoneyBadgerRy]

Originally Posted by ninjayetti

Thanks for the clarification.

I already purchased the petcock kit.

This is going to start getting expensive.

To be clear, the bike runs and idles just fine once warm. With that being said, I'm still not sure if it's running too lean, but that might be the case if the bowls need adjustment, correct?

Thanks again!

Ryan

If the floats need adjusted it could be to lean or to rich (depending on which way they need adjusted) since you are overflowing with gas I have to assume its running to rich.

[ninjayetti]

Originally Posted by HoneyBadgerRy

If the floats need adjusted it could be to lean or to rich (depending on which way they need adjusted) since you are overflowing with gas I have to assume its running to rich.

Thanks again. And when you say I should replace the fuel seals, do you mean the gaskets?

Thanks!

Ryan

[HoneyBadgerRy]

Originally Posted by ninjayetti

Thanks again. And when you say I should replace the fuel seals, do you mean the gaskets?

Thanks!

Ryan

I meant to say float needle seals, which is just a different way of saying float needles. They should come in any carb rebuild kit, if not they could a be ordered on jetrus.com

[ninjayetti]

Originally Posted by HoneyBadgerRy

I meant to say float needle seals, which is just a different way of saying float needles. They should come in any carb rebuild kit, if not they could a be ordered on jetrus.com

Perfect, thank you!

This is a solid video on the principles of adjusting the floats:

https://www.youtube.com/watch?v=Xj220oY26Yo

Again, thanks for all your help!

[ninjayetti]

Originally Posted by HoneyBadgerRy

Your petcock is always stuck on on.

Hi There,

Finally got around to removing the tank and petcock. I took the petcock apart, and everything appears to be 100% fine. Now I'm confused, because it was 100% leaking a lot of fuel when the bike is off.

Any ideas?

Ryan

[HoneyBadgerRy]

Originally Posted by ninjayetti

Hi There,

Finally got around to removing the tank and petcock. I took the petcock apart, and everything appears to be 100% fine. Now I'm confused, because it was 100% leaking a lot of fuel when the bike is off.

Any ideas?

Ryan

The petcock consist of a rubber diaphram and a spring that kept the diphram sealed. The vacuum pressure overcomes the spring and opens the diphram.

Either one of the parts is missing, the diphram is ripped, or the spring is on the wrong side of the diphram.

[ninjayetti]

Originally Posted by HoneyBadgerRy

The petcock consist of a rubber diaphram and a spring that kept the diphram sealed. The vacuum pressure overcomes the spring and opens the diphram.

Either one of the parts is missing, the diphram is ripped, or the spring is on the wrong side of the diphram.

Here are some photos:http://imgur.com/a/5RBh1

It was assembled correctly, according to the petcock diagram on this site. http://faq.ninja250.org/images/0/03/832902.jpg

As far as I know, the petcock was never taken apart, so not sure how it could have been put together incorrectly.

P.S. When i checked the petcock, I pulled out the larger of the two hoses while the bike was off, and it leaked fuel continually. Also, it continued to leak fuel when the tank was removed, as well.

Thanks

[HoneyBadgerRy]

Originally Posted by ninjayetti

Here are some photos:http://imgur.com/a/5RBh1

It was assembled correctly, according to the petcock diagram on this site. http://faq.ninja250.org/images/0/03/832902.jpg

As far as I know, the petcock was never taken apart, so not sure how it could have been put together incorrectly.

P.S. When i checked the petcock, I pulled out the larger of the two hoses while the bike was off, and it leaked fuel continually. Also, it continued to leak fuel when the tank was removed, as well.

Thanks

Everything seems to be in order. Test the petcock and see if it leaks. You should be able to use a little hose and water to see if its working properly.