Fauna Bose Posted July 24, 2010 Posted July 24, 2010 I started my YAMAHA DRAGSTAR 650 after Three Months. It did start after a couple of Cranks. It idles alright but the Engine dies when I rev it. What could be the problem ? I can only think of two reasons. 1. The little Black Box (Relay, Ignition Coil ?) in between the Battery and the plugs is not throwing enough current (But then why does it idle alright?) 2. Carburator fuel jets may be clogged. PLEASE HELP.
KirriePete Posted July 24, 2010 Posted July 24, 2010 Battery got a good charge? If in doubt, whip it off and stick it on a decent charger for an hour or two. If it's been sat for 3 months with fuel in the carbs it's a fair bet that some of the jets will be clagged up with that lovely varnish-like residue. You might be lucky and get away with a good blast of aerosol carb cleaner down the intake and up from the float bowl - if not then a good soak in carb cleaner/paraffin and a blast through with compressed air should do the trick. HTH OH yeah - the choke is working OK, isn't it?
Moderator mervin Posted July 24, 2010 Moderator Posted July 24, 2010 have youbput fresh fuel in the tank, modern fuel goes stale overnight nearly
chris66 Posted July 24, 2010 Posted July 24, 2010 if you have a good battery then its your carbs, the reason its idling but not revving up is that there is probably a idle jet and a main jet, one being blocked worse than the other . if your technically able then a carb strip, clean and balance is best. if your not so brave empty tank, undo the drain screws on the carbs, refill tank with new fuel mixed with a carb cleaner additive. its not cheap, about £15, but if you run the bike for a few minutes a day for a few days sometimes it clears the jets, cheaper than the garage but not always successful.
Moderator Airhead Posted July 24, 2010 Moderator Posted July 24, 2010 have youbput fresh fuel in the tank, modern fuel goes stale overnight nearly I have a Rover 25 car that used to belong to my eldest daughter, she upgraded in August 2008 and this car remained un-used on my drive for over 18 months. My youngest girl passed her test in due course and to give her driving experience I had to swap cars and start to use this Rover car (which has cost me a small fortune) I was worried about trying to start it due to the ancient fuel, not least because it had been hanging around in there all through last winter which was the coldest on record Any way one new battery later and a turn of the key......Vroom The exhaust needs replacing
root Posted July 26, 2010 Posted July 26, 2010 Yeh my mate decided to have a look at & get his Lomax with a Citroen 2cv flat 2 lump out of his sons garage to prepare for mot, its been untouched for 5 year. We put a fully charged battery on cleaned plugs,fired up first time & sounded spot on & these are somewhat like motorbike engines 600cc . We ran it for a while just in the yard ,then put it back in the garage this was about 5 weeks ago & I wouldn't be surprised if its still there for another 5 years ! ( I'll show him this post it might gee him up a bit )
HoughMade Posted July 26, 2010 Posted July 26, 2010 An engine that will idle, but not rev is kind of a classic sign of a lean idle/low speed condition. Another vote here for new fuel and cleaning the carb. I don't think new fuel alone will do it.
chris66 Posted July 26, 2010 Posted July 26, 2010 the instances on here of engines starting fine after long periods with old fuel are cars. car engines normally have one big carb feeding all cylinders, it would take too much varnish to stop them starting. a bike on the other hand usually has one small carb per cylinder with smaller jets, very easy to block. also most older car engines have not got the fine tolerances bike engines have. my 750 has 123 hp thats more than most 2000 cc cars, the fueling has to be right or it suffers. it sounds like your main jets have been partially blocked by varnish meaning when you rev you trying to run on thin air
root Posted July 26, 2010 Posted July 26, 2010 the instances on here of engines starting fine after long periods with old fuel are cars. car engines normally have one big carb feeding all cylinders, it would take too much varnish to stop them starting. a bike on the other hand usually has one small carb per cylinder with smaller jets, very easy to block. also most older car engines have not got the fine tolerances bike engines have. my 750 has 123 hp thats more than most 2000 cc cars, the fueling has to be right or it suffers. it sounds like your main jets have been partially blocked by varnish meaning when you rev you trying to run on thin air Yes we know its just a bit of comparison!
Moderator Airhead Posted July 26, 2010 Moderator Posted July 26, 2010 I posted about 'the car' in response to Mervs @fuel goes stale overnight' comment...it seems not, and I agree that the root cause of trouble will be the carbs..either gumming...although I doubt it after only 3 months, or evaporation...more likely IMO. Each year I lay my Bandit off for the winter and each year in the spring it will idle and not rev. So I just switch the fuel to prime and let it idle until hot with gentle coaxing of the throttle a few blips here and ther along the way. This approach has never let me down and nothin's more certain than next spring she will idle and not rev
chris66 Posted July 26, 2010 Posted July 26, 2010 i agree each bike is different when i had a fzr 400 it was a nightmare, couldn't leave it for two months without having to perform some sort of carb clean. i bought some carb additive, you use it in the last but one tank of fuel before putting you bike to bed for the winter, and yes it did work.
blackhat250 Posted July 26, 2010 Posted July 26, 2010 remained un-used on my drive for over 18 months. Aye auld een " i kno where your coming from, That H2 i bought last year, had sat in a garage for over a year, coz guy was in far east, when we dug it out [ surounded by a dozen other bikes under blanket,] turned on key " ignition lights:unsure: , fourth kick and it fired:rolleyes: , Amazing , Oh and my money is on the pilot jets blocked .
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