Bike Won't Stay Running - Looking For Ideas

[aharnak]

Hey y'all,

As a few of you may remember, I bought my 2007 250 with 7,800 miles off of a friend maybe a month ago, somewhere around there. It was running fine when I bought it. Obviously it's not running so well right now, so I'll try to explain the issue the best I can - there are a lot of variables. I apologize in advance for the long post and promise to read and respond to a few long posts in return for your kindness, haha.

This all started after I performed the first maintenance on the bike. I didn't do anything drastic, replaced the fuel lines (the reserve one was cracked and badly leaking), put an in-line tractor fuel filter on the main fuel line, changed the oil and filter with 1.9 quarts of 10W-40 Shell Rotella T6, and adjusted the tire air pressure. Like I said, nothing crazy. So a big question mark for me was the fuel line with the filter. The filter is pretty big, so there wasn't really that much space for it, and I had to make a bit of a bend in the fuel line to accommodate it. I figured the worst case scenario is that if the engine weren't getting enough fuel, I'd pull it out and just put in a straight fuel line.

Not sure if this is related, but a couple days after the fuel change, I came out to the bike at work and there was a big puddle of oil underneath it. I tightened the drain plug and the fuel filter plate bolt. There was some oil left, and it was my ride to work, so using really really low RPM's, I rode to the Target (basically across the street), bought a quart of Mobil 1 10W-40, poured it in, checked for leaks, then rode it home. It's been weeks since this happened, but I figured I'd bring it up in case anyone thinks it's relevant.

So after this whole fiasco, the bike had been running relatively well for a few weeks. However, as I got more in tune with the bike, I noticed a little bit of hesitation right around 7k RPMs, and it seemed to be worse when it was cold outside. No sign of backfiring on deceleration, though. I figured it wasn't getting enough fuel due to the filter/kink in the line, and I'd change it when I had time.

So fast-forward to earlier this week. I still hadn't gotten around to removing the filter. I was riding in to work (about 20 miles away), on the turnpike doing around 70 mph. Suddenly the bike started to lose power, like I was running out of fuel. I switched the petcock to reserve and it still continued to lose power. I pulled over and it stalled. I checked the gas tank, and the level was definitely not low enough to warrant using the reserve. I switched it back and cranked the engine until I was afraid the battery would die, no luck. I tried starting it with the choke on, and it fired up immediately. So I rode away with the choke on, and backed it down to no choke after a minute or two.

The bike was fine until I got off the highway, then it started to lose power again. Seemed like nothing I could do would prevent it from stalling. I made it the final mile or two to work by alternating between choke and no choke, but it was getting worse by the minute and I ended up just creeping along sputtering into the parking lot.

I was hoping that after work it would fire right up because the engine was cooled down. Unfortunately it didn't work out that way. It started with choke on, but any time I gave it any throttle at all, it bogged and stalled. I towed it home with the help of a friend.

I let it sit for a few days because I hadn't had the chance to look at it. Yesterday, I took a crack at it by removing the fuel filter. I also checked out the spark plugs, and although I didn't have a gapping tool, they didn't look fouled. It started initially, but exhibited the same symptoms as before. I ended up killing the battery by cranking it so much.

So what am I to do? I figured I should clean the carbs, but is there a way to do that where I don't have to soak them for four days like the wiki article says? What about Seafoam? Any other ideas? What else should I check? Besides charging the battery, cleaning the carbs, and maybe replacing the spark plugs, I really have no idea how to proceed with this. Any ideas are greatly appreciated.

[Motofool]

Originally Posted by aharnak

..........replaced the fuel lines (the reserve one was cracked and badly leaking), put an in-line tractor fuel filter on the main fuel line..........

There is only one fuel line, no main no reserve.

The smaller hose is for vacuum from the engine that sucks from the petcock to open a diaphragm valve.

In 99% of the cases, the problems come from the last thing you modified.

For that reason, I don't believe that your carbs are suddenly so dirty.

I will assume that your new hoses are rated for gasoline use.

The easiest thing to check is the abundance of fuel flowing into the carbs for the three positions of the petcock.

In order to do so, disconnect the end of the hose going into the carbs and put it inside a glass container.

No gas should flow in the closed position.

No gas should flow in the normal position.
Disconnect the vacuum hose from the petcock and connect a new long hose there. Apply vacuum at the other end (mouth or syringe). At least 2 cc per second should flow while vacuum is applied.

The same should happen for the reserve position.

http://faq.ninja250.org/wiki/Rebuild...tcock/fuel_tap

It would be best if you can reproduce the configuration of the fuel hose, just in case you have created an air pocket that restricts the flow.

If everything is good, check the little screen filter inside the intake nipple of the carbs.

If all is good, check for water in the bowls:

http://faq.ninja250.org/wiki/Draining_the_carbs

[FvnnyL3tt3r1ng]

I have had similar issues with my 250 from time to time. If it runs fine with the choke you know the issue is somewhere in your carburetor. In one instance I had to clean out the main jets because a tiny flake of debris got into one and blocked fuel flow.

The other instance required me to troubleshoot leading me to find the float valves had gone bad. You do this by opening up one of your (2) carb bowls at a time and draining the fuel. Hold the starter and observe fuel flow. If there isn't a steady stream of fuel then your float valves are not letting fuel into the bowls and they need to be replaced. I was told the rate of flow was 2cc/second but when my float valves went out it was painfully obvious because one side was a steady stream and the other side was just dripping fuel out.

Hope that helps.

[FvnnyL3tt3r1ng]

Did you remove the OEM fuel filter before putting the new one in?

[aharnak]

Originally Posted by FvnnyL3tt3r1ng

Did you remove the OEM fuel filter before putting the new one in?

Yes, in fact I set it aside and can't find it now... so for the time being I'm going commando

[aharnak]

Originally Posted by Motofool

There is only one fuel line, no main no reserve.
The smaller hose is for vacuum from the engine that sucks from the petcock to open a diaphragm valve.
For that reason, I don't believe that your carbs are suddenly so dirty.

Didn't know that! So if the one tube is the fuel line, and the second is the vacuum hose, what's the third one that goes to nowhere? Vent?

Originally Posted by Motofool

For that reason, I don't believe that your carbs are suddenly so dirty.

I really didn't think so either, but my knowledge of carburetors is limited, and I thought maybe if the bike was running rich or lean due to the new fuel filter, something in the carbs became fouled.

Originally Posted by Motofool

I will assume that your new hoses are rated for gasoline use.

Yep, they're Goodyear fuel/emissions hoses.

Originally Posted by Motofool

It would be best if you can reproduce the configuration of the fuel hose, just in case you have created an air pocket that restricts the flow.

Can you explain this a little more? Not really sure what you mean.

[aharnak]

Thanks for the info guys, I have some things to check now... I'll update as necessary.

[Motofool]

Originally Posted by aharnak

Didn't know that! So if the one tube is the fuel line, and the second is the vacuum hose, what's the third one that goes to nowhere? Vent?

We must be talking about different things here.
The cockpit has two connections.
Please, see the schematics in my links above.

Can you explain this a little more? Not really sure what you mean.
If the hose makes a S bend, air pocket will be trapped on top.

[aharnak]

By the way, Moto, I was referring to the third nipple coming from the very back of the gas tank my the seat

[Motofool]

Originally Posted by aharnak

By the way, Moto, I was referring to the third nipple coming from the very back of the gas tank my the seat

That is just the drain from the well of the tank's gap.

[DaBlue1]

Originally Posted by aharnak

.... a couple days after the fuel change, I came out to the bike at work and there was a big puddle of oil underneath it. I tightened the drain plug and the fuel filter plate bolt. There was some oil left, and it was my ride to work, so using really really low RPM's, I rode to the Target (basically across the street), bought a quart of Mobil 1 10W-40, poured it in, checked for leaks, then rode it home. It's been weeks since this happened, but I figured I'd bring it up in case anyone thinks it's relevant.

Where was the oil leaking from? Did a whole quart leak out?
Have you looked at your air filter or airbox at all?
An air filter saturated with oil can choke the air coming into the bike. It can mimic the symptoms you are experiencing as well.

[kirk595x]

I'm a huge believer in Seafoam. It really is the only Miracle additive out there in the automotive industry. I have clean out more carbs with it than I can remember. If you can get it to run by choke then put a few ouncesof Seafoam in your tank, keep the bike running if you can for a few minutes and constantly rev. The idea is to get the Seafoam into the Carb so it can start working on any deposits or carmelization. Let it sit overnight and do the same process all over again. If no improvement then re-trace your steps and get that kink out.

When I bought my 03' with 3k miles it would barely run even with choke. I had to pull the carbs and do a full cleaning cause it had sat with the previous owner for too long.

[aharnak]

Thanks for everyone's input, and for living up to the title of the "friendliest" Ninja 250 forum on the net . The winner is Motofool! I walked my bike to the gas station (next door) and filled it up. I checked the flow of gas and it was perfect. I picked up a battery charger at Walmart and brought the battery back to life. I drained the carb bowls, and alas, there was a bit of water and whitish cloudy gunk at the bottom of the container I used to catch it. Put some Seafoam in the tank, cranked it to fill up the bowls, and it fired up. I let it run for 15 minutes or so, then took it out for a nice long test drive, and it feels great. I even managed to find a smaller fuel filter to use, one that fits on the fuel line without me having to bend it awkwardly to make space. Test drove it again and it seems fine. Thanks to everyone, but Motofool, next time you're in the Philadelphia area, beer's on me!

[Motofool]

You are welcome, A.J.

Glad you solved the mystery !!!