Page 5 of 5 FirstFirst ... 345
Results 61 to 74 of 74

Thread: Sport City 250 Stalling

  1. #61
    apriliaforum expert armadillored's Avatar
    Join Date
    Aug 2006
    Location
    Cleveland, Ohio, USA (now in Murrells Inlet, SC
    Posts
    1,405
    I had the same stalling problem with mu 250. It was the fuel pump - the old style one and it was replaced under warrantee by the dealer. Since then (about 3 years ago) it works perfectly. Apparently the pump heats up and sizes to the housing. Then it has to cool off before it will work again.
    '67 BMW R69S-"Toots" in rehab
    '09 Silver SC250
    Previous rides:
    '04 Chinese 125
    '06 X9-500
    '08 MP3-400
    '06 BV500

    '09 Mana

  2. #62
    apriliaforum expert
    Join Date
    Apr 2011
    Location
    Clearwater, Fl
    Posts
    8,028
    Quote Originally Posted by armadillored View Post
    I had the same stalling problem with mu 250. It was the fuel pump - the old style one and it was replaced under warrantee by the dealer. Since then (about 3 years ago) it works perfectly. Apparently the pump heats up and sizes to the housing. Then it has to cool off before it will work again.
    Hopefully they did not accidentally send him another old style fuel pump however even that should have worked for some time before failing again.

    Some mess up though when they replace the fuel pump or work on the fuel system since they do not fill up the tank with at least 2 liters of fuel to cool and lubricate the pump during its initial prime. Try to prime a new fuel pump without enough fuel to completely submerge the pump and you can ruin it. This is also critical when storing your bike for an extended period of time since you need to have enough fuel to cover the top of the pump during storage so you won't be starting it with a dry fuel pump.

    This information is on page 164 of the Service Station Manual.

  3. #63
    apriliaforum expert armadillored's Avatar
    Join Date
    Aug 2006
    Location
    Cleveland, Ohio, USA (now in Murrells Inlet, SC
    Posts
    1,405
    That's good to know Rockynv. When I stored my bikes and scooters for winter, I always filled up the tank and put in gas preservative.
    '67 BMW R69S-"Toots" in rehab
    '09 Silver SC250
    Previous rides:
    '04 Chinese 125
    '06 X9-500
    '08 MP3-400
    '06 BV500

    '09 Mana

  4. #64
    apriliaforum expert
    Join Date
    Apr 2011
    Location
    Clearwater, Fl
    Posts
    8,028
    Fuel injection systems with submerged rubber impeller pumps require special considerations. Running out of gas or even continuing on once the low fuel level light comes on can cause the fuel pump to fail too. Its best to fuel early and not wait since pump replacement is costly and labor intensive. Some people found out the hard way trying to run their fuel injected bikes dry for storage only to find they had compromised the fuel pumps in doing so.

  5. #65
    apriliaforum expert armadillored's Avatar
    Join Date
    Aug 2006
    Location
    Cleveland, Ohio, USA (now in Murrells Inlet, SC
    Posts
    1,405
    Good advice Rockynv
    '67 BMW R69S-"Toots" in rehab
    '09 Silver SC250
    Previous rides:
    '04 Chinese 125
    '06 X9-500
    '08 MP3-400
    '06 BV500

    '09 Mana

  6. #66
    apriliaforum newb
    Join Date
    Dec 2013
    Location
    Middlesex
    Posts
    13
    Quote Originally Posted by Rockynv View Post
    Hopefully they did not accidentally send him another old style fuel pump however even that should have worked for some time before failing again.

    Some mess up though when they replace the fuel pump or work on the fuel system since they do not fill up the tank with at least 2 liters of fuel to cool and lubricate the pump during its initial prime. Try to prime a new fuel pump without enough fuel to completely submerge the pump and you can ruin it. This is also critical when storing your bike for an extended period of time since you need to have enough fuel to cover the top of the pump during storage so you won't be starting it with a dry fuel pump.

    This information is on page 164 of the Service Station Manual.
    Hi,
    I had filled the tank the day before fitting the new pump, (checked my credit card fuel receipts to see exactly when), and with premium unleaded ultimate from BP, (98 octane I think). Unfortunately it doesn't appear to be the pump as the one I took out was showing good pressure before I did and was the revised one anyway with three dots on the top. The new one was also the revised one with three dots on but I thought I'd give it a try in case it was the regulator or filter despite the good pressure reading.
    I have my replacement coolant hose on order as I have spotted some damage to one, and the clutch bearings to fit which will keep me busy this weekend if they arrive in time, though I don't believe the bearings will be the answer given there's no drag at all when on the stand as the wheel can actually stay stationary it idles so low when it isn't cutting out. I hope I'm wrong.
    I'm still going through the regime of fuel system cleaner additive with each tank of fuel in the hope I see some improvement but again I don't think I'm seeing any after three tanks full with a good quality additive in each. The first bottle cost more than a tank of fuel!
    I've found my multi-meter so will check battery/frame resistance.
    I'm going to see if I can check the coil and maybe the pick up next if there is test data for both. Am looking to see what there is in the manual shortly.

  7. #67
    apriliaforum newb
    Join Date
    Dec 2013
    Location
    Middlesex
    Posts
    13
    Whilst waiting for parts to arrive I haven't done much more but it has given me time to think. I've said it previously I think but I'm tempted to go back to the start of cleaning the throttle body. Part of my thinking behind this is that when spraying cleaner down the air bypass to try and clean the stepper moving part that reduces and increases airflow I wonder if I'm only getting cleaner onto the part that is exposed and what about the rest of the 'plunger' (or whatever it is called)? m I not cleaning it thoroughly enough to ensure it moves properly, how can I be sure I cleaned the whole of the plunger and the channel it moves back and forth in? Is it getting stuck in areas I can't get cleaner too with the spray throttle body cleaner?
    As a result I started to google the cleaning of the throttle body looking to see if anyone has actually opened it and removed the stepper motor. I couldn't find anything that indicates anyone that has or has opened the body up at all. All I found was the below image on Magnetti Marelli's website of it open.
    Click image for larger version. 

Name:	ECU.jpg 
Views:	7 
Size:	240.0 KB 
ID:	376625
    Anyone opened it up?
    Can I pull the stepper if I do and clean the passage the plunger sits in?
    Will it go back together with the stepper set correctly or is there a danger it goes out of sequence?
    Any experience or advice appreciated.

    If I get to the point where I have to buy one then I have nothing to lose trying it but not really up for doing so until then if the risk is high.

  8. #68
    apriliaforum expert
    Join Date
    Apr 2011
    Location
    Clearwater, Fl
    Posts
    8,028
    I believe that Micah from AF1 has commented recently on some issues with the throttle body along with provided some info on work around's to get past some age related issues without having to invest in a new throttle body. I haven't had any problems with mine so I've yet to open it up.

  9. #69
    apriliaforum newb
    Join Date
    Dec 2013
    Location
    Middlesex
    Posts
    13
    Ah yes, the vacuum port using a mower petcock. I liked that idea and it would offer a temporary solution whilst I continue to work out what is going on. Would want to fit it to a spare air intake manifold though.

  10. #70
    apriliaforum Junkie
    Join Date
    Jun 2016
    Location
    Florida
    Posts
    369
    Quote Originally Posted by Rockynv View Post
    Fuel injection systems with submerged rubber impeller pumps require special considerations. Running out of gas or even continuing on once the low fuel level light comes on can cause the fuel pump to fail too. Its best to fuel early and not wait since pump replacement is costly and labor intensive. Some people found out the hard way trying to run their fuel injected bikes dry for storage only to find they had compromised the fuel pumps in doing so.
    dude you are so full of shit that its a chore to come here anymore. You drivel your bullshit all over this forum and dont know shit all about working on two wheels. Do new fuel pumps come soaked in fuel? Gee I wonder why? But dry storing a pump makes it fail?? hahahahhahaah But you know everything. Like your missing spacer theory. Face it... you are a freaking hack wrench with the diagnostic ability of a single cell amoeba and made trivial mental errors like forgetting to install all the parts you took off. One thing is for sure... Im not the only person that feels this way about your constant misinformation campaign.
    How much would it take for me to buy you out of your sportcity? $500?

  11. #71
    apriliaforum expert
    Join Date
    Apr 2011
    Location
    Clearwater, Fl
    Posts
    8,028
    Quote Originally Posted by superloopy24v View Post
    Ah yes, the vacuum port using a mower petcock. I liked that idea and it would offer a temporary solution whilst I continue to work out what is going on. Would want to fit it to a spare air intake manifold though.
    Removing a few bolts and the fuel injector along with the purchase of a $53 intake fitting. Did Micah's work around require modification of the intake or just tapping into an existing vacuum line?
    https://www.af1racing.com/store/Scri...ING+%2D+875694

  12. #72
    apriliaforum newb
    Join Date
    Dec 2013
    Location
    Middlesex
    Posts
    13
    Quote Originally Posted by Rockynv View Post
    Removing a few bolts and the fuel injector along with the purchase of a $53 intake fitting. Did Micah's work around require modification of the intake or just tapping into an existing vacuum line?
    https://www.af1racing.com/store/Scri...ING+%2D+875694
    I only just got round to this yesterday. I was waiting on a used inlet manifold I bought on ebay complete with injector for £50 and a day off work to get on with it.
    I drilled a hole in the intake manifold I bought and threaded the hole to take a modified car brake bleed nipple (using parts I had laying around my garage), I cut the tapered end off the brake bleed nipple so it has a clear passage right through it for air to travel and the other end enables me to push a hose on with a spring hose clip to secure it. At the other end of the hose I put the petcock with the filter, and wrapped the filter with a piece of foam cut from a new but no longer required air filter i had for a 50cc I no longer have.
    I don't think there was really enough room for the petcock to be secured straight into the intake manifold and I wouldn't have been able to get my hand to it to open and close it as I might need hence the hose which has ended up longer than I'd have liked to ensure it ended up accessible outside the bodywork.
    I've only used it briefly yesterday evening but I think it made a difference, I'll use it more over the coming days to get to work to test it properly. It certainly hasn't cured it, but that might be because the air flow is not adequate as the hole may be a bit smaller than necessary, (and smaller than the original bypass passage), as well as it not metering fuel air as strictly as it should be. Perhaps with more parts to hand a larger passage would have been better with the tap on the petcock being more useful as a result.
    However in the limited use yesterday evening it didn't run quite as badly when coming off throttle and engine speed slowing to idle, (I wasn't holding the throttle open and working it as I slowed down to prevent it cutting out and running roughly which I have had to do a lot recently). It did still stall a couple of times but as it wasn't running as rough I would have been able to keep it running without having to give it enough throttle that it wanted to take up drive and then hold it back on the brakes which is what I've been having to do at times.
    I tried uploading a couple of pictures of how I modified the inlet before I fitted it but they won't upload so maybe too large to allow me.

    On another note I also bought an old and scabby used MIU but it is for a 125cc to mess about with opening up. I've figured out you can get it apart if you scrape the silicone bonding around the perimeter and lever it apart but that you have to be careful in doing so not to lever it too far as the 26 pin connector is bonded internally to the rear face of the throttle body side of the two cast pieces whilst most of the PCB is attached to the other part of the casting. You can do so enough to be confident it is separated without really pulling the halves apart and then by placing block of wood on that and pressing it evenly it broke the silicone bond without damage to the 26 pin connector or PCB.
    Really can't see how to pull the stepper motor at this time as it may be pressed in and won't come out as easily as I hoped, there's nothing to pull on or lever it out to clean behind so will give it some more thought.

    Craig

  13. #73
    apriliaforum newb
    Join Date
    Dec 2013
    Location
    Middlesex
    Posts
    13
    Name:  20190402_121851small.jpg
Views: 31
Size:  43.2 KBName:  20190402_122056small.jpg
Views: 30
Size:  43.2 KB

    Reduced the file size and it worked

  14. #74
    apriliaforum newb
    Join Date
    Dec 2013
    Location
    Middlesex
    Posts
    13
    Click image for larger version. 

Name:	20190418_113051.jpg small.jpg 
Views:	8 
Size:	104.5 KB 
ID:	379574Click image for larger version. 

Name:	20190418_120747.jpg small.jpg 
Views:	8 
Size:	100.1 KB 
ID:	379575Click image for larger version. 

Name:	20190418_141220.jpg small.jpg 
Views:	8 
Size:	102.2 KB 
ID:	379576

    So I've waited ages for my coolant hose but as it didn't turn up yet and I've chased it to find out it's on back order I got on with fitting these recently purchased alternative parts to see if they made any difference to running at idle over what I already fitted as there's a larger bore to the pipe, the fitting, the flow valve, and clearly the air filter. It hasn't really made any substantial difference to what I'd previously fitted so whilst it works a treat some of the time it does still dip in engine speed and pick up again at idle with occasional stalling, mostly once warmed up. It's much easier to keep running though with a tiny throttle blip when it does.
    Just means I've got to strip it again for the coolant hose fitment when it does arrive.
    Not made any progress on getting the stepper out of the other throttle body yet, am toying with seeing if I can pressurise it with a compressor and force it out or drilling into the body somewhere to drive it out in a location that can then be repaired; perhaps on the end where I imagine the air chamber either side of the stepper plunger and see if the whole thing can be pushed from the centre if there's a shaft to push on.

Page 5 of 5 FirstFirst ... 345

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •