bike wont run :(

M

modifiedamerican

Been Around the Block
so i got a kz750b4 twin a little over a month ago. rode great but had to have the choke on. cleaned the carbs,floats,adjusted the floats, cleaned the jets all that good stuff. now the bike ran without the choke up but still wasent quit right. found out that i needed a new coil.so i got a emgo one from z1 enterprises and it fired right up but still something was a little off. put new spark plug caps on and new plugs also. rode it around. parked it for like a week. came back to the bike to work on it. it started but wouldnt stay running. cleaned the float bowls and jets out again thinking maybe something was clogged. put everything back together and it wont start. it doesnt seem like its getting any spark either and i dont no why! its a new coil,new wires,new plug, and new caps. im stumped :'(
 
Well there are two things that usually can go wrong. carbs and jetting, and electrical. Since you have already done the carb and replaced a coil. I would check your fuses first, loose wires, and I assume that you have electronic ignition and no points?? Have you checked your timing? If you have points, inspect them, check the gap and make sure it is timed correctly. Let me know how it turns out.


Bullit ;D
 
i actually have points ignition. and i did clean the points off. also i dont no how to time a motor so i cant check that. im assuming the timing is good because it ran like a top when i first got the bike,just with the choke on.lol.. i took the cover off to clean the pints and everything was spotless. every part behind the cover looked brand new! ill check my fuses and wires though. any other suggestions?
 
How old is the battery? Sounds like its not keeping a charge. Test it and see what its at. Most bikes (especially old ones) will not start on a crap battery.

Make sure your point and plug gaps are correct.

Take a plug out, and stick it in the plug boot. Hold it against the engine case and have someone kick the bike. Poor mans way of testing spark. If its dark in the garage, you'll see a spark. You'll feel it too if your hands close... Haha. Only hurts for a second.
 
the battery isnt that good. its on its last leg. i recharged the battery though and tried to see if i see a spark but i didnt see a spark.
 
Whats the voltage at the terminals? If its under 12.5 after a proper charging, the battery is shit. If it is 12.5 or over, and you turn the ignition on only to have the voltage drop dramatically, the battery is shot.

Im willing to bet that your battery is toast. Buy a new one. Auto Zone sells them if you dont have a bike shop nearby. Just make sure you fill and charge the battery properly.
 
If it needs choke all the time, that tells you it's too lean somewhere. Your issue seems to be the bottom end, so I'd try one size larger pilot jets and adjust the air screws to get it running sweetly.

It could also be the fuel drillings through the carb may still be partly blocked. Clean them again and blow through them to be sure.
 
Check your rubber boots in between your carbs and the engine for leaks. That was the problem with my dads GS1000G when it would only run with the choke on. The cracks got bigger one day and it wouldn't run at all.
 
i dont have the choke problem at all any more. after i cleaned the carbs that problems went away and was all good. atleast rideable. i put a new emgo coil on and it fired rite up and just need some carb ajustment still.. let the bike sit for about week cuz i couldnt work on it because of work. went to work on it yesterday and it started up but wouldnt stay running. and then i couldnt get started at all..i dont no what it could be other then a battery maybe?
 
charged battery after resting for an hour or so after charge should read around 14.5 volts. any less then 13 and its usually shot. your stator (alternator) is probably on its way out if you have charging issues. if the bike runs well after a fresh battery but the condition declines the more you ride it, then stator is completely fubared.
 
I had a very similar problem with a Suzuki GS550 of about the same vintage. Turned out to be a bad regulator.
 
That sounds like the battery isn't holding a charge. Check it with a multimeter
 
teazer said:
That sounds like the battery isn't holding a charge. Check it with a multimeter
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That's what the Zuki was doing, even after we put in a new battery. Whipped out the multi meter and started poking around the charging system and found that the regulator wasn't reading the proper impedance. Stuffed a good one in there and bingo. The PO damn near gave the bike to my friend because of this problem. He let it go for $350 in great shape with a clean title just to get it out of his Garage. All this after doing the carbs, new plugs, etc. Basically, he was chasing the wrong problem. We fixed it in a day. Well, and evening really.
 
modifiedamerican said:
is there a way to test the regulator? and is the regulator the same as the rectifer?
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Found some pages from the manual. See attached.
 

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Lets not overthink this already... Haha.

He already said the batter is bad. Replace it, charge it, and see if that works. Start with the simplist solutions first.
 
VonYinzer said:
Lets not overthink this already... Haha.

He already said the batter is bad. Replace it, charge it, and see if that works. Start with the simplist solutions first.
Click to expand...


I WILL OVER THINK YOUR FACE!!! ;D hehehehe.
 
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