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Clubroom => Tech Talk => Topic started by: caps 999 on February 07, 2009, 09:59:34 pm

Title: cr480 wont start
Post by: caps 999 on February 07, 2009, 09:59:34 pm
gday all having a bit of 480 troubble ran fine yesterday now today there is no life carby gets fuel theres spark and a new plug but after 300 kicks it still looks like a new plug it seems like fuels isnt making it to the plug could a leaking head gaset cause this at all or could it be something else its got me stuffed any suggestions  ???
Title: Re: cr480 wont start
Post by: hotdog1975 on February 07, 2009, 10:05:45 pm
did'nt leave the rag in the airbox................. ???
Title: Re: cr480 wont start
Post by: caps 999 on February 07, 2009, 10:10:22 pm
haha nope but i changed the main jet to a 175 from 178 though
Title: Re: cr480 wont start
Post by: E74 on February 07, 2009, 10:20:07 pm
jets are blocked
Title: Re: cr480 wont start
Post by: caps 999 on February 07, 2009, 10:35:13 pm
ive checked that still nuffing
Title: Re: cr480 wont start
Post by: oldyzman on February 07, 2009, 10:40:21 pm
How about if you prime the bore with a capfull of fuel and then kick it..
Title: Re: cr480 wont start
Post by: caps 999 on February 07, 2009, 10:42:45 pm
done that im baffled
Title: Re: cr480 wont start
Post by: LWC82PE on February 07, 2009, 10:56:30 pm
if its not firing with fuel or instant starting fluid down the plug hole you might have a timing issue. any chances the timing as slipped/moved?
Title: Re: cr480 wont start
Post by: hotdog1975 on February 07, 2009, 11:06:43 pm
not a faulty "new" plug...?? try the old plug again.
Title: Re: cr480 wont start
Post by: VMX247 on February 07, 2009, 11:08:48 pm
fuel cap breather blocked . 8)
I don't know who first put this idea up ,but I've pinched it and have used it ever since  :-\
I think it was oldtimer or oldyz or someone old   ;D  8)  
anyway hope it runs well with the next effort or tomorrow. :)
cheers Alison
Title: Re: cr480 wont start
Post by: caps 999 on February 07, 2009, 11:11:39 pm
tried 3 differnt plugs ignition is fine is it possible to get vaper lock on this model cause im stuffed
Title: Re: cr480 wont start
Post by: hotdog1975 on February 07, 2009, 11:16:27 pm
sheared woodruff key..??
Title: Re: cr480 wont start
Post by: caps 999 on February 07, 2009, 11:29:00 pm
ignition timing is fine it seems like no fuel is making it to the ignition stroke
Title: Re: cr480 wont start
Post by: jimg1au on February 07, 2009, 11:46:39 pm
if you put fuel down the plug hole or areostart and it dosnt fire it the problem IS IGNITION as you have fuel there but no ignition.i had the same problem with my 1973 cr250m the ignition coil was new but faulty.just sit back and think. you have spark.you have put fuel in cylinder via the plug hole and still not firing it is ignition.
cheers
jim
Title: Re: cr480 wont start
Post by: 090 on February 08, 2009, 08:16:47 am
Also , if it was running fine before you changed the jets over, there is a good chance it is in the carby. Make sure the slide is in properly and cable hasn't been pulled out of the top of the carby. A bike is impossible to start if the throttle is stuck half way.
Title: Re: cr480 wont start
Post by: Hoony on February 08, 2009, 08:23:47 am
if all else fails it could be an intermittant cdi fault. i had a similar problem. is the spark VERY strong?
Title: Re: cr480 wont start
Post by: Snowy 76 on February 08, 2009, 10:22:14 am
Sure it`s not just Flooded ?, had similar just recently on my 480, Plug  Didn`t look wet, Pulled out plug, 3rd gear, gave her a push for a 100 mtrs  or so {once all weezing and coughing had ceased} plug back in  2nd kick way she went. Just a thought.
Title: Re: cr480 wont start
Post by: caps 999 on February 08, 2009, 10:45:05 am
i have a small feeling it may be the plug cap as the fit looks kinda lose but there is a string spark when i remove the plug and hold the cap
Title: Re: cr480 wont start
Post by: jimg1au on February 08, 2009, 12:38:38 pm
dont muck about looking at this and that.give a good dose of gas or areo start down the plug hole put new or working plug back in.it will start if there is no ignition problems.i use ths method on boats for years.i have a 70hp yamaha,i bidnt use it for 18months due to injury.charge up battery and wind over.no fire i had spark no fuel.speezed fuel bulb again cranked over nothing.took 1 plug out sprayed areostart into cyl.replaced plug.fired up first turn of key.problem now fuel del at cold.electronic enrichener $300.00 is at fault.also check that the motor is not full of fuel i am asumeing you carb needle and seat is in good condition and you didnt leave fuel tap on and crankcase is not full of fuel.i bought a 1979 it400f once of a guy said it was running last month.the obove needle and seat combined with leaking fuel tap was all that was wrong with the bike.
have fun try 1 thing at a time and document your efforts so you can see whats happening
cheers
Title: Re: cr480 wont start
Post by: oldyzman on February 08, 2009, 03:58:48 pm
Good point snowy76, I had an old mx which would not go with a new plug, i adj timing played with fuel and even tested the coil. the fault was a bad new plug- put the old one back in and it went ok
Title: Re: cr480 wont start
Post by: pancho on February 08, 2009, 04:12:04 pm
i bet it was an ngk
Title: Re: cr480 wont start
Post by: caps 999 on February 08, 2009, 05:17:37 pm
problem solved turns out the bike was well past floded i pulled the head off got the piston to the bottom of the stroke and tiped the bike i got around a litre of fuel out the bottom end i res assembled and it strated first kick i dont know how that much fuel got in the bottom end but it rides like a weapon now  ;D spent the arvo at parwan and had a ball
Title: Re: cr480 wont start
Post by: oldyzman on February 08, 2009, 09:53:17 pm
Hey wally it was ngk.... Glad to hear you got it started, my brothers old it175 did that when we were kids and he thought it was seized as the crankcase was full of petrol- needless to say he always tuned of the fuel when stopped from that point on