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Discussion Starter · #1 ·
Hi i have 78 cx500 i have been trying to get going,ive removed the carbs and cleaned them have good spark,but it wont actually start,on refitting the carbs i have left off the carb to airbox rubbers for now and have noticed when i try to start i get a lot of fuel coming out the back of the carbs,she nearly goes i get the odd splutter and puff and also when nearly starts it sounds as if the bike is trying to lock up i get a clunk then she spins over fine again,any help would be really appreciated thanks
 

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Hi i have 78 cx500 i have been trying to get going,ive removed the carbs and cleaned them have good spark,but it wont actually start,on refitting the carbs i have left off the carb to airbox rubbers for now and have noticed when i try to start i get a lot of fuel coming out the back of the carbs,she nearly goes i get the odd splutter and puff and also when nearly starts it sounds as if the bike is trying to lock up i get a clunk then she spins over fine again,any help would be really appreciated thanks
You need those carb boots on there, otherwise it gets way way too much air.
 

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Howdy and welcome to the forums! The good people here will help you get sorted out.



You may have done a fantastic job of cleaning out your carburetors - I don't know how you work, though, so we'll start there. I thought I knew a little bit about cleaning carburetors until I read a few threads here, especially regarding the work of Larry Cargill. He goes by the name of LCXRed on the forum. He has rebuilt hundreds of these carburetors and his technique involves pulling all of the jets - some that I didn't even know were there - and cleaning them in an ultrasonic cleaner. I spent the $90 on the cleaner, $25 on his manual, went through my carburetors and man, did it make a big difference! There are other excellent methods for cleaning carburetors documented in this forum and they all have one thing in common for me - what I used to think was clean was not even close.



I assume you are using fresh gas and fresh plugs? Others will chime in. Loudergood makes a great point, too. Probably try with the boots on.
 

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hi Bob,other than the carb clean......any more history to tell us?work wise on the bike.?



as said,put your boots on,it probably wont run with them off.

battery age and condition,plugs, new,or old?



give us a bit more info



do you like brains?
 

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What else have you tested or are you sure its the carbs? Little bit more info will definitely get this fixed quicker. Also, during testing I start my bike without pod filters and with the choke pulled in, so it will start if its all good.
 

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Discussion Starter · #7 ·
Thanks for the replys i got the bike couple of weeks ago in a right sorry state was told it was running but more than likely the carbs needed cleaning,the bike hasnt been run for some time its had new plugs and plug leads theres a nice spark at the plugs got a new battery on it fresh fuel,i didnt have a key with the bike but thanks to a previous post on here ive figured out how bypass that,and linked the red wire to black giving me ignition lights, im not sure it is the carbs but its making me think it is due to the amount of fuel coming out the rear of them any other suggestions? thanks very much for your help so far
 

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Discussion Starter · #8 ·
[quote name='bandit' date='07 August 2011 - 09:10 AM' timestamp='1312726207' post='100173']

hi Bob,other than the carb clean......any more history to tell us?work wise on the bike.?



as said,put your boots on,it probably wont run with them off.

battery age and condition,plugs, new,or old?



give us a bit more info



do you like brains?




Cant say ive tried brains yet so not too sure
 

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I don't think the boots not being installed will cause the bike to not start. I think it would start and idle OK,,it may not work well above idle but it should start.



The clunking you describe sounds like it could be the starter clutch.



It also sounds like it could be flooded,,you could try shutting the fuel off and see if it may start, if not, it might not hurt to remove the plugs and dry them off and spin the engine over a few times with the fuel turned off and the plugs out. Then with dry spark plugs installed give it another try. A shot of starting spray may help too.
 

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do you like brains?




Cant say ive tried brains yet so not too sure
i did a lot of work around the mumbles,this was my tipple

[3.7%

 

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Thanks for the replys i got the bike couple of weeks ago in a right sorry state was told it was running but more than likely the carbs needed cleaning,the bike hasnt been run for some time its had new plugs and plug leads theres a nice spark at the plugs got a new battery on it fresh fuel,i didnt have a key with the bike but thanks to a previous post on here ive figured out how bypass that,and linked the red wire to black giving me ignition lights, im not sure it is the carbs but its making me think it is due to the amount of fuel coming out the rear of them any other suggestions? thanks very much for your help so far
Bob,i think it is your carbs,or at least take them out of the equation.for the price of 1/2 of brains follow this thread,you will reap benifits.also fit an inline fuel filter,,,,ok a pint price for your cleaning fluid and a filter.


http://globalcxglvtwins.hostingdelivered.com/viewtopic.php?f=19&t=140

take your time,be methodical,we will be here to help.......

i dont think its worth moving on until you have had a go to clean them
 

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Easy test.

Leave your Carb to air box boots off. It will start and idle fine without them.

That is how I did 90% of my testing.

Shut off your fuel, drain your carbs.

Shoot carb cleaner into the carbs with the throttle wide open. Pull your choke and try to fire it up.

If it fires and runs for ... oh say 10-15 seconds your carbs are in need of a lot more attention.
 

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Ahhhh that kind of Brains!!!!!!!!!
Have tried but prefer lager.
what kind of brains did you think i meant?



ok,now you have given away your age.lol.



seen the picture,pull the carbs
 

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You may have a float stuck down or something keeping the float needle from seating. When you had the carbs apart did you check to see if the overflow tubes (brass tubes in the float bowl and rubber hoses on the bottom of the bowls) were clear?
 

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In my bikes case there was some goo in the main fuel line from the petcock. I pulled the gas tank, and removed the petcock and fuel lines. Also the vaccuum advance hose was splitting on both ends so I read on here that THAT is what suck the butterfly valve closed in the carb when they have no gas in them on a cold start..something like that, so I cut off the damaged ends of the vac advance hose and reattached it, also getting gunk outta main fuel line. And spraying inside of petcock out with carb cleaner, including the inlet pipe and the filter element, and the float bowl. I also remove the face thing on the petcock and sprayed into there. It looked clean. Reassembled everything. She started up and idled for 5 minutes on the second crank. I had to shut it off. It was cool.
 

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do you like brains?




Cant say ive tried brains yet so not too sure
i did a lot of work around the mumbles,this was my tipple

[3.7%



IPA all the way! The bitterer the beterrer!
 

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Discussion Starter · #19 ·
Hi well good news after all your help ive finally got it running after stripping the carbs and thoroughly cleaning them,they stopped leaking
but it still wouldnt start,then the starter motor started to slow down on me but following the links on this site i removed it,stripped it and cleaned everything put it back on and the bike was flying over,still wouldnt start....so i checked the coil wires where they join in the loom they were right yellow joined yellow and purple joined purple,decided to swap them over anyway one press of the starter and boom she fires up! i couldnt belive it,so somebody had previously fitted the coils the wrong way round! if i could find him id kill him...lol. but thanks again for your help with my questions im sure il have some more shortly
 

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well done Bob,what a great way to start the day


i could nearly hear it fire up.


another member had the same thing,a few months ago,coil wires being swopped over by po.



a right result




edit,did i mention......i like IPA
 
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