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I would like to thank all in advance for any advice I recieve.

I own an 82 Yamaha 750 maxim, I have got single air breathers, for my 4 carbs and I removed the carbs to clean out and install air filters. Before I removed the carbs, the bike ran fine, however now it won't start.

I do know the carbs are getting gas to the bowls, and the spark plugs have a spark but for reasons beyond me, I can't get the bike to start now. I have tried starter fluid, and putting gas directly into the cylinders, but I still can not get it to start. Let me also add, since then, I have removed and cleaned the carbs twice more, thinking I might have missed something when cleaning them.

Can anyone suggest why it won't start?

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what are the symptoms of it not starting when using starter fluid? does it stutter? or does it not fire at all? did you connect the High Tension leads to the correct plugs? –  Mauro Jul 23 '13 at 11:31
    
oddlly, no will not even bark, and yes all wires r to the right plugs. all it does is turn over –  user3454 Jul 23 '13 at 17:31
    
Are you getting compression? has anything else been changed? it should at least splutter with starting spray unless something is drastically wrong - timing, ignition, compression. Any fuses blown? –  Mauro Jul 23 '13 at 17:40
    
yes there is compression, and no, nothing else has been changed, trully mind boggleing, ran fine before i cleaned carbs and added filter, why would the gas not go from carbs to cylinder –  user3454 Jul 23 '13 at 17:46
    
i even removed air filter to see if a vacuum was felt from back of carbs and felt something –  user3454 Jul 23 '13 at 17:48

2 Answers 2

Have you checked to make sure you don't have a vacuum leak? This can be caused by any hoses that aren't plugged in but it can also be caused by a bad carb gasket or a carb that isn't tightened to spec. Checking for vacuum leaks is hard without the engine running, but you can do a spot test by simply pulling off a vacuum hose and putting your finger over the hose when you crank the engine. You should be able to feel a little bit of suction.

Another possibility is that your carbs are not choking properly. I am unfamiliar with this particular bike but I would assume the choke is electric. It is possible that the wires for the choke weren't hooked up correctly, or that the choke is stuck open for some reason.

These are my best ideas, but I'm sure someone more familiar with the bike might be able to suggest more specific things to check.

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no it does not have an electric choke, it is manual, and as far as vacuum hose, the only vacuum line on the bike, is from the fuel tank to the boot, the only lines that even go to the carb is the throttle cable, the choke cable, and the fuel line, but thank you to takeing the time to reply –  user3454 Jul 22 '13 at 21:18

My guess is you flooded it (possibly stuck needle after the first rebuild). And by putting gas and starting fluid directly in the cylinders, you have privacy made it worse and washed out the rings on the piston and have essentially lost compression. Typically, I would turn off the gas tank petcock so that no gas is getting to the carbs, and crank it for a good ten to twenty seconds (you can usually here compression returning, or it will spit and sputter and nearly run). It may take longer, but give the starter a good thirty seconds rest between the ten to twenty second cranks. Once it spits and sputters, or you can definitively hear compression returning, turn on the gas and try again but do not give it any throttle!

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