tazzer1993 Posted June 9, 2014 Posted June 9, 2014 Hello everyone. Have bike and brain malfunction today.It's hard to pinpoint exactly what is going on so I thought I would have an ask on here.Starts up fine when cold. Bit of a pain to work the choke out to stop it revving the nuts off itself or die. Once warm, no problems running for about ten mins, then will randomly die for no explainable reason. Will struggle to start again unless left to cool for a while. Now, it gets even more confusing. While riding, it feels sluggish at anything less than 8k revs. Real bad flat spot at 5-6k. Anything beyond 8k is fantastic though. plenty of power, no throttle delay. Also, at constant speeds of about 20-40, it will splutter constantly until the throttle is opened up. I am utterly bewildered as to what to do with the carbs to fix this issue. Would a simple clean out do the trick? Or perhaps balancing and re-jetting?Thanks. Shiny side up Quote
Mr Fro Posted June 9, 2014 Posted June 9, 2014 A good old scrub wouldn't do any harm. While you're at it, you might as well balance them up (or at least check the balance) as the cleaning process can usually disturbs something or other...As for jetting, I'd only look at this if had always been running poorly or if it had occurred since it had been tinkered with (exhaust, air filter etc).The range you describe is probably the needles anyway so they might just need a shim or two. Have fun! Quote
tazzer1993 Posted June 9, 2014 Author Posted June 9, 2014 Ok. Hopefully shouldn't be too much of a pain. Had enough issues trying to put on the new push throttle cable! Stupid placwe to put it haha. Right behind the frame and coils. Quote
Guest Posted June 12, 2014 Posted June 12, 2014 I had a similar problem with my old VF500, its was the carbs in the end. Try pulling the plugs to have a look at which carb is letting you down. To fix the problem with mine I just cleaned out the carbs, blew out the jet and away she went. Quote
tazzer1993 Posted June 13, 2014 Author Posted June 13, 2014 Fair enough. Anything I should be particularly careful about when cleaning the carbs? Quote
Mr Fro Posted June 13, 2014 Posted June 13, 2014 Erm... Give them a good going over with carb cleaner and a toothbrush on the outside before opening them up to avoid getting extra crap in there.Do one at a time so as not to get needles and jets mixed up.Be gentle when removing/installing jets and tubes as it's easy to strip the threads.Watch out you don't put a screwdriver through a diaphragm if you have them.Check the intake rubbers for cracks and splits while you're there.If you've got the OEM specs for the idle screws, needle shims etc then use them when reassembling.Have a brew on standby. Quote
tazzer1993 Posted June 13, 2014 Author Posted June 13, 2014 Sounds like a plan to me! this is going to be a fun weekend. Time to do ALL of the maintenance! Quote
Chrissb6 Posted June 13, 2014 Posted June 13, 2014 Hi before you go a ripping down the carbs first be sure to check the fuel lines and the vacuum pipe from the fuel tap as well as the tank breather pipe. I find it strange that it fires up and run sweet then dies. That suggests to me that its a fuel supply problem. If your going to strip the carbs down be sure to take pictures of how it all go's back together, so that you can back track if you loose your way. Carbs on a V 4 are tricky to say the least to take out and reinstall. Quote
tazzer1993 Posted June 13, 2014 Author Posted June 13, 2014 Oh fantastic. I think many hours of head scratching and talking to myself are heading my way. Oh well. I do hope it's an easy fix because other than the running issue, she is sweet as a nut. Quote
Chrissb6 Posted June 13, 2014 Posted June 13, 2014 Oh fantastic. I think many hours of head scratching and talking to myself are heading my way. Oh well. I do hope it's an easy fix because other than the running issue, she is sweet as a nut.Id would say hoses Mate, that would be my first port of call. Don't go looking for trouble Quote
tazzer1993 Posted June 13, 2014 Author Posted June 13, 2014 It's all worth a shot! Might as well start with the obvious things and slowly work towards dismantling the carbs. Cheers for all the info Quote
eastanglianbiker Posted June 14, 2014 Posted June 14, 2014 spray some wd40 or carb cleaner around the hoses with engine ticking over if revs increase you have a problem on one of the hoses dont go mad with spray and do small area at a time so you can tell problem area if there is one Quote
tazzer1993 Posted June 20, 2014 Author Posted June 20, 2014 Too late haha. Already discovered the source of the problem. The jets were clogged to hell so just bought new ones and soaked the carbs in a stack of carb cleaner. She runs like a dream now Quote
eastanglianbiker Posted June 20, 2014 Posted June 20, 2014 glad its all sorted and you are out there enjoying it now well done Quote
tazzer1993 Posted June 20, 2014 Author Posted June 20, 2014 All very helpful info. Now I just need someone to do some cheap paintwork and she will be as good as new...I hope haha Quote
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