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Discussion Starter #1
ok, so i have an 86 vulcan 750 and it ran fine last year. i havent started it in a year and am now trying to bring it back to life. the battery was dead so i got a new battery and put it in. the new battery was much smaller and i had to put a piece of 2x4 underneath it just to have it at a high enough lvl to put the wires onto it. it ran for the first time i tried to start it and then wouldnt work after that. the time it did start, it ran like crap and i could not use the throttle or it would stall which led me to believe the carbs were gunked up. i took them off and cleaned them real nice and put them back on. it did not start after that at all. it tries to turn over but nothing. so i figured maybe the plugs went bad somehow. i checked the plugs and the front 2 are wet with gas and the rear are dry. both have lots of black charcoal stuff on them like it was running rich. i got new plugs and tried again, still nothing. so i guessed the spark was bad. i put a screwdriver tester up to it and the spark was there but very weak. remind you that last year with the other battery it was fine running and now with the new one it is not. so the question that i have is.... is the new battery so small that the amps or volts coming from it to power the rest of the bike, so small that it isnt enough for the bike? should i buy a new battery thats bigger like the old one? also is there anything else i should try? thanks in advance :)
 

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our bikes take a lot of juice to start. you should have something at least like an etx15l. I would start there, put it in and turn your petcock to prime! choke it and give it a shot, if it starts let her run on choke a few minutes and turn the petcock to run.
 

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Discussion Starter #3
thanks, i will try that in the afternoon tomorrow, i am going to pick up the bigger battery then. what exactly does prime do? i have never used it, does any gas free-flow out when you use prime or is it sucked out?
 

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Sounds like a combo of issues. The front plugs were wet and not firing, rear dry and no gas getting to them. Sounds like the battery was causing a weak spark that had trouble firing the front plugs when they had gas to burn. Of course the carb not delivering gas to the rear cyl has been hopefully remedied. I'd definitely follow the instructions above using the carb cleaner and seafoam. Run seafoam in your gas tank for a while once you get her going again.
 

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What about the possibility of the fuel tank having contamination inside. Causing what flaco mentioned, recontamination.
I did not see anywhere on the thread where the old gas was emptied and replaced with fresh gas, not to mention the fuel lines.
I was watching a show about boat fuel systems, in fact they were rebuilding a set of carbs. And how the ethanol in the fuel after sitting there and mixing with air can cause varnish build up. Maybe you still have contamination inside the fuel tank.
 

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Discussion Starter #7
i emptied the old gas out before even attemtping to start it up, but only had regular gas to replace it with. i just bought some seafoam to put in the gas tank, should i use regular gas or supreme? also is there any ideas how to maybe clean the inside of the tank before i use the foam? so that any thing that may be ready to fall off gets taken out before hand? like something to put in and shake it around maybe. also the bigger batterys from walmart/sears were all out so i called the dealer to buy a gel battery instead.
 

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87 (regular) octane gas is what this bike calls for. You could remove the tank and add some seafoam to the gas, like a whole can or a half can and shake up the tank, let it sit, shake it again every 30 minutes or so then drain it into a gas can. If the gas comes out reddish colored or you see dark brown debris then you have some rust to deal with. If it comes out clean, tank should be fine.
 
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