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Joffter

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About Joffter

  • Rank
    TT Bronze Member

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  • Location
    South Africa
  • Interests
    Motocross, Cricket, cycling
  1. Joffter

    2007 CRF250R cuts out/dies at full throttle

    Too late, already sent it in for welding.
  2. Joffter

    2007 CRF250R cuts out/dies at full throttle

    Pulled it apart last night. Turns out there is a small hole punched in the wall between the crankcase and gearboc, just below where the chlinder sits on teh crankcase. Presumbly from a piece of broken piston previously, as the current piston is still intact, but with lots of blow by on the rings. Thanks again for the advice, will strip and have it welded up and machined properly.
  3. Joffter

    2007 CRF250R cuts out/dies at full throttle

    If you whack it open from idle or lower RPM, it dies, like its starving of fuel. If you roll it on, while riding, it accelerates as per normal but gets to a point and sort of starts hesitating and jerking a bit, like it is being held back. The bike had a different aftermarket needle in it with no markings when it arrived at my workshop which was a Gold colored needle. I took the needle out the other bike i borrowed so I could swap parts over till I traced the problem, and checked and tried it, and although its not quite the right needle for the bike, its noticeably thinner than the one that was in the bike. End result, the bike still has a bog off idle if you crack it open, but doesn't die anymore.............so we have progress. I then asked my 17 year old son who races 250's to test it for me today while I am at work, and he has reported back that the bike is now running and revving properly right through the range, and also seems to start easier. So it appears that my problem has been a completely incorrect needle in the bike all along, which I suppose I should have realised, but was under the impression from the owner that it was running fine before he brought it to me to rebuild the bottom end and new Piston and Rings. With the needle that was in the bike, I cannot understand how it ever ran properly. So it would seem the problem all along has been fuel starvation on the mainjet all along, due to the wrong needle. Will double check and test it tonight and see. Thanks to all who contributed to this with advice etc. Much Appreciated. Next project i have is trying to fix a Yamaha 200 Blaster that is somehow getting gearbox oil into the crankcase, this after the crankcase seal has been replaced twice, and the seal has for sure been installed the right way round. Any Ideas ?
  4. Joffter

    2007 CRF250R cuts out/dies at full throttle

    Hi Guys, Will be looking at these tips tonight. I have checked the fuel pump is pumping out the nozzle. Have removed the subframe so I cna run the bike on the stand and check into the carb while it is running. Nozzle has been checked, removed and cleaned and put back, and is definitely squirting a jet into the throat of the carb as it should. I have another CRF250R exactly the same, which I have borrowed and will use that for trouble shooting and part swapping till I trace the issue. I have however already ascertained that teh borrowed bike also dies if you crack the throttle open rapidly from idles. Like it bogs and just doesn't recover unless you let the throttle go. May just be that I am asking it to do something it simply cannot deliver. I didn't have that issue ith my RMZ450's at all. They were very responsive and revved almost like they were fuel injected, but i did have jetting specs and tips from a factory team which helped. May just be that this particular bike is just too lean, so have richened it up a bit and will test after work. Wil report my progress either way. Thanks to all who have responded with advice. Everu bit of it is appreciated.
  5. Joffter

    2007 CRF250R cuts out/dies at full throttle

    Went through the Carb again last night. Stripped, completely, including the middle section. I am sure its all clear and clean. I also changed the fuel pump diaphragm, and tried again. Revs nicely off the bottom if you blip it, idles great. Snap it open to full throttle, mwhooooooooooooooo, dies straight away like you have hit the kill button. Let the throttle go and it catches again and idles. As long as you keep the throttle to the stop it is dead, leave it and it runs. Only at full throttle. Whats the chances its the TPS sensor ?
  6. Joffter

    2007 CRF250R cuts out/dies at full throttle

    Will give that a try as well.........
  7. Joffter

    2007 CRF250R cuts out/dies at full throttle

    To be honest I have no idea on the amount of hours. Its a bike I am fixing for a friends brother. The bottom end, incl Mains/big end and piston and rings just been done by me, but we didn't do head/valves. Reason for doing it was the big end had gone, so wasn't running when it was brought to me either. Valves wern't done as he didn't want to spend more money and valve clearances were ok. More info is that the bike does also stand for months at a time as the guy works in Europe, so only rides it like twice a year when he gets back here.
  8. Joffter

    2007 CRF250R cuts out/dies at full throttle

    Hi Charlie, Thanks for the reply and help. Sorry if I cam across wrong, I do not mean to sound like I know it all or anything like that. I have been doing bikes for many years, but this one bugger of a bike has me stumped so will try anything I can that may help. Going to have a go at the leak jet system again and swap out the fuel pump daiphragm as well and see. Valve springs and valves were not changes or messed with besides slight shimming as they were not completely out of spec but close so I shimmed them. I haven't had the valves checked to see if they sealing properly or not. Trying to avoid pulling it apart again. Geoff
  9. Joffter

    2007 CRF250R cuts out/dies at full throttle

    Thanks for the response. I have tried anything from a 160 through to a 185 main, with no difference whatsoever. I did remove the carb, a number of times, disassembled and re-assembled. Been doing 4 stroke Carbs for 8+ years, so know my way around them quite well. There is play on the Hot Start lever, on the handlebars, but will however check again that its seating properly at the carb. When you ride it normally, its fine up till half throttle, but if you run it at full throttle, opening the throttle smoothly it does not run well. It runs like an absolute dog, sort of spluttering and not accelerating at all. Crack it open quick like off the start gate type thing and it dies there an then. It also doesn't backfire/pop or crackle at all either, which it surely would if it was lean, especially if you back off, or revving it hard. Most 4 strokes I have had and raced, if you nail it hard, at high RPM they will crackle if running lean. Any other ideas will be gratefully accepted and tried..........
  10. Hi, Need some help with this one please. I have a 2007 CRF250R I am working on for someone. Bike has had a new bottom end and top end and been shimmed. Valve clearances all in spec. Cam timing also perfect, been checked a dozen times. It battles to start but I can get it started when cold. Warm it starts fine Idles fine, and rev it from idle it revs like it should. Actually feels nice and responsive from idle if you rev or blip it. Crack the throttle wide open from idle or even from mid rpm, and it dies like you hit the kill switch. Back off and it idles. When riding it if you open the throttle slowly to full throttle, it runs but then you can feel it stops pulling/running liek a dog at full throttle. Whack it open fast at it bogs and cuts like its dead, back off and it runs and idles. I have cleaned the carb and am sure the carb is clean. Tried different plugs too. Fresh fuel as well has been tried. Jetting I have tried ultra lean from a 160 main through to a 190 main and it makes no difference. Pilot is a 42 and needle 3rd clip, fuel screw at 1 1/2 turns out but have also tried several settings there. Bang it open hard and it cuts, back off and it fires up again. Any ideas please ?
  11. Joffter

    CRF250R 07 starting issues

    Hi, OK, I have read virtually every thread related to not starting on this and other models, and still no Joy. This particular Bike has just been rebuilt(for a mate, not my bike), I have done big end, mains,piston and rings etc. Valve clearances are perfect, have doubled checked numerous times, cam timing is spot on, appears to be spark at the plug, and Carb is clean, which I have double checked as well, properly. If I try kick start it, no joy, it will not kickstart when cold. If I bumpstart it, it fires immediately, first bump and runs fine. I know how to start a 4 stroke having raced them for years and my son races a CRF250 as well. I can however get it started eventually with the kickstart when cold, if I use no choke, and use the hotstart lever, and after a number of kicks it will start. This tells me its rich and the additional air from the hotstart lever opening is assisting it to run. It kick Starts fine once warm. With choke u cna forget it. Any body got any ideas ??? I know this has been flogged to death but need to get it running. It has a 42 Pilot in it and a 172 main and we are at around 1300m above sea level.
  12. Joffter

    2009 & 2011 CRF450 Plastics

    They are not the same. The 2009 Side Number boards are slightly different in that they have an air vent in the side number board, hence it will not fit. I did mine last week. You can make it fit easily enough, by simply trimming the air vent piece that sticks into teh 2009 Airbox with a sharp blade. Simply cut it off/trim it on the airbox side of teh cover and it fits straight away. You will not even really tell the difference once its on either. All the rest of the plastics fit straight on though.
  13. Joffter

    08,09 RMZ450's

    I have one and love it. Same as some other guys mentioned Previously, I seem to get holeshot's a lot more often than ever before. It's like when I am on the line I almost know I will holeshot. The bike rips, and revs plenty far enough for a 450. I have not had a single hiccup with mine. I had the EFi tuned a little with the Yoshi box at a dealer friend of mine after we did a lot of testing with different settings, and now the bottom is about the same, the mid is stronger as well as the top end revs further.
  14. Joffter

    Here is the 09 RM-Z's

    No RM85L ????? What do all the kids who ride Suzuki RM85L's do now ?? Buy another brand ? I think there may be something new in the pipeline, that they are yet to announce. I have also heard something from someone high up in Suzuki Management about a bike in the same class.
  15. Joffter

    Back fire screen Question

    Buy an RM250 Filter cage. They are exactly the same, but without the screen. Hardly cost anything. I have been running one since my first RMZ450 in early 2005, without any problems at all. Never damaged a filter.
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