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2014 450 still having weird running issues

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I made a thread last fall when having trouble with my 14 450 and I still haven't been able to figure it out. I figured I would just start a new thread.

The bike will start up fine and I can go riding for a while (couple hours) and then all of a sudden I could go to give it throttle and it will just start cutting out and sound really weird if held to the rev limiter. I can shut it down and wait a few minutes, fire it up and it runs fine. This happened yesterday tho I stopped riding because I didn't want to crash on the jump. Started fine today and ran fine for the 15 minutes or so I was gone to test it. My gytr tuner isn't showing any codes and my local Yamaha dealer doesn't even have the big diagnostic tool. I'm kind of at a loss here and really want to get this figured out.

to me it sounds like an electrical issue, timing is dead on and valves are in spec. With a fairly new top end put in and a new spark plug. I'm thinking about striping the bike right down and closely inspecting the wire harness and every plug on the bike to make sure there aren't any flaws in them, but would like to get some feed back as I don't want to just go buying sensors and be no further ahead.

here is a video of how it runs when it is acting up 

 

Edited by ttr230rider6

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Never ever go to the rev limiter! It's there to protect you from floating a valve spring and bending a valve....if you keep hitting it, you are more likely to do just that.

The rev limiter in nuetral is lower that in any other gear, as well.

Have you serviced the fuel pump, pump filter, and pump harness, and injector yet?

It could be a simple as a corroded pump wire connection.

 

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10 hours ago, Krannie McKranface said:

pump

 

10 hours ago, Krannie McKranface said:

Never ever go to the rev limiter! It's there to protect you from floating a valve spring and bending a valve....if you keep hitting it, you are more likely to do just that.

The rev limiter in nuetral is lower that in any other gear, as well.

Have you serviced the fuel pump, pump filter, and pump harness, and injector yet?

It could be a simple as a corroded pump wire connection.

 

I tried to take my fuel pump apart to clean the fuel filter but I felt as tho I would break it prying on the little tabs. I hooked the injecter up to a 9v battery and sprayed contact cleaner through it and it came out but I didn't get it professionally cleaned. And by pump harness do you mean the white plug that plugs into the fuel pump? 

In my head I don't think there would be an obstruction in the fuel pump or the fuel line/ injector because it runs fine for a while and then starts to act up, and then will run fine again, so it seems to me like there is a connection broke somewhere or something like that

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1 hour ago, ttr230rider6 said:

 

I tried to take my fuel pump apart to clean the fuel filter but I felt as tho I would break it prying on the little tabs. I hooked the injecter up to a 9v battery and sprayed contact cleaner through it and it came out but I didn't get it professionally cleaned. And by pump harness do you mean the white plug that plugs into the fuel pump? 

In my head I don't think there would be an obstruction in the fuel pump or the fuel line/ injector because it runs fine for a while and then starts to act up, and then will run fine again, so it seems to me like there is a connection broke somewhere or something like that

Sounds like the pump is failing. The typical symtom is that it works fine for 5-10 min, then you loose power.

The filter, if clogged, will cause the pump to fail, eventually, as the pump needs a minimum amount of fuel to operate correctly, otherwise it gets damage.

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1 hour ago, Krannie McKranface said:

Sounds like the pump is failing. The typical symtom is that it works fine for 5-10 min, then you loose power.

The filter, if clogged, will cause the pump to fail, eventually, as the pump needs a minimum amount of fuel to operate correctly, otherwise it gets damage.

Alright, I will probably try the tank from my buddies bike for a day and see where that leaves me!

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The fuel pumps have gotten cheap(er) for those bikes now.  About $250.

On mine, it starting getting a parasitic loss of pressure.  I only noticed it when I removed the fitting from the fuel pump and it kept weeping fuel at the spigot, so whatever little check valve in there was starting to fail.

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41 minutes ago, GHILL28 said:

The fuel pumps have gotten cheap(er) for those bikes now.  About $250.

On mine, it starting getting a parasitic loss of pressure.  I only noticed it when I removed the fitting from the fuel pump and it kept weeping fuel at the spigot, so whatever little check valve in there was starting to fail.

So fuel isn't supposed to come out of the little white part that the fuel line connects to when there is no fuel line attached?? Fuel weeps out of mine when the tank is off!!

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Likely the same issue then.  When you let off the throttle, are the RPM's super low?  Like, below idle for a second, then creep back up to idle speed?  That's what mine did until I replaced the pump.

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27 minutes ago, GHILL28 said:

Likely the same issue then.  When you let off the throttle, are the RPM's super low?  Like, below idle for a second, then creep back up to idle speed?  That's what mine did until I replaced the pump.

It hasn't been doing that lately but it has before. That video I linked is from last fall, and I haven't changed anything since then. And in he video it does go below idle and then come back up. The last couple times I've been out it idles fine and starts fine but after a while I get the same type of bog that I got in that video.

Did your bike have a bog and cut out as well?

I just got back from a run on it to see if it would act up and it ran fine the whole time, other than a couple times I tried doing a couple endos (back tire did not come up a big lot) and the bike would cut out. And there was definitely a half tank of fuel in it. Do you see anything wrong with that or is that normal?

there is 114 hours on the bike and I have never filtered gas before filling so I honestly wouldn't doubt but the fuel filter is real dirty.

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Mine would occasionally cut out.  Sometimes when on the gas, sometimes when chopping the throttle.  No bog, no blubbering, just abruptly OFF.  Always started right back up.  

It also did that from about the 30 hour mark.  Maybe once every 20 hours or so?

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7 minutes ago, GHILL28 said:

Mine would occasionally cut out.  Sometimes when on the gas, sometimes when chopping the throttle.  No bog , no blubbering, just abruptly OFF.  Always started right back up.  

It also did that from about the 30 hour mark.  Maybe once every 20 hours or so?

That's when mine would mostly act up. Wide open on the face of a jump or snapping the throttle open for a wheelie or something. Wouldn't always just shut right off. Sometimes it would cut out sometimes it would stay going. This seems to be problem. So when you put a new fuel pump in yours your problems went away?

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9 hours ago, ttr230rider6 said:

 

The pump doesn't usually just 'die', it just gets weak.

It's supposed maintain 55+ psi at all times.

If you were to test it off the bike for 5min+ you would see it start to drop over time, expecially if you request WOT levels of fuel....

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19 hours ago, Krannie McKranface said:

The pump doesn't usually just 'die', it just gets weak.

It's supposed maintain 55+ psi at all times.

If you were to test it off the bike for 5min+ you would see it start to drop over time, expecially if you request WOT levels of fuel....

Alright I'll have to test my pump then to see for sure. Not sure if it says in the manual how to do it but I won't have access to my manual until tomorrow, what's special tools are needed to do this and what is the procedure?

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1 hour ago, ttr230rider6 said:

Alright I'll have to test my pump then to see for sure. Not sure if it says in the manual how to do it but I won't have access to my manual until tomorrow, what's special tools are needed to do this and what is the procedure?

You can rent/borrow a psi meter for FI testing at a chain autoparts shop.

You can use water for the test

 

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On 2017-04-17 at 9:14 PM, Krannie McKranface said:

You can rent/borrow a psi meter for FI testing at a chain autoparts shop.

You can use water for the test

 

Thanks for the videos man, i checked a couple local spots and they didn't have anything available for me to rent. I know a guy that had his own bike shop out of his home that might have something to do it.

In the mean time, to speed things up, I ended up borrowing my buddies tank off a basically brand new bike to try again. I took it for a spin today with my tank on and it acted up in no time. So I rode home and then swapped tanks. Was just it for about an hour or so and it never acted up at all. However I was also out the other day and it didn't act up either. I then put my tank back on and it didn't act up the whole time I was out. So I am going to do a few more test runs with his tank before I come to any conclusions.

When I took my tank fuel dripped pretty steadily out of the white nozzle that the fuel line connects to and my buddies tank didn't leak any.

My local Yamaha dealer (not knowing the above information about test runs with different tank, as I was talking to them a yesterday) thinks that it is the tps sensor as they have had a couple in the past with issues. To which I would just swap the whole throttle body and get all new sensors and injector because they don't have the diagnostics tool to set the tps, and they said the whole throttle body comes with it factory set. 

Any more thoughts on the situation givin this info?

 

Edited by ttr230rider6

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TPS failure can tell the ECU to stop providing fuel pulses, but that is not common.

A TPS either works or it doen't

Your pump sounds bad. You need to get it HOT to make it fail. Higher rpms and loads will do that.

Is your tank venting properly?

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2 hours ago, Krannie McKranface said:

TPS failure can tell the ECU to stop providing fuel pulses, but that is not common.

A TPS either works or it doen't

Your pump sounds bad. You need to get it HOT to make it fail. Higher rpms and loads will do that.

Is your tank venting properly?

Alright, I'll try and get it real hot and give it a hard ride to see what I can find out. The vent hose is free of obstructions (I can blow air through it) and fuel will leak out of the gas cap hole where the hose connects so I assume that it would bent properly? 

But in saying that I could try and get it to act up and then loosin off my gas cap to see if anything changes.

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20 hours ago, Krannie McKranface said:

TPS failure can tell the ECU to stop providing fuel pulses, but that is not common.

A TPS either works or it doen't

Your pump sounds bad. You need to get it HOT to make it fail. Higher rpms and loads will do that.

Is your tank venting properly?

I was just out for another run where I ran the bike a bit harder than normal, hard to really push it in the area I'm able to test in. Never acted up at all with either tank on. I also popped the gas cap off just to see if any pressure was built up and there wasn't.

the other day when it acted up with my tank on I wasn't out any more than 15 minutes and I wasn't riding real hard, so I'm kind of thinking that it isn't the tank, tho I will do a third test again tomorrow or the next day. 

http://m.vitalmx.com/forums/Race-Shop,42/2015-YZ250F-PROBLEMS,1285291?page=1

i know that is a Farley big thread to read but he was having similar problems it seems and it turned out to be the tps sensor, what are your thoughts after seeing some of those posts? (I know it's a lot of reading but it would be greatly appreciated if you checked it out, as I am getting really frustrating, and it seems like any option I am going to have to try to fix is roughly 500 dollars, fuel pump - 430, throttle body - 500)

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