Bike runs. unless i let it sit overnight

81 xj650 maxim. bike runs great but if i let it sit overnight, even with the trickle charger running it still wont kick over. i have to use the multi meter looking for power loss somewhere and at some point try to start it it startup and then is great. i can turn it off and right back on. only when it sits for a long while does it not start. Is there a switch or coil i need to look at that's not holding a initial charge or something? Thanks for any suggestions.

 

How old is the battery? Not to sure if it is the bike or the battery? In checking the bike with the multi meter, you should be using the amp setting and remove the pos wire from your battery and put the meter inline between the wire and the battery post. That is how you would check the draw with the key off.

If the batter is a few yrs old, I would check the battery to see if it is holding a good charge and if when under load it is also good.

Have you replaced the old bus glass fuse panel yet? If not, make sure you clean them old contacts up. Most of us change out the old glass bus fuse panel for a newer type.

 

Battery has been replaced 2x now in all my trouble shooting. Also the fuses have been changed. its getting a drawdown somewhere during start. ive changed out starters, fuses, electronic components, spark plugs. it runs great when i get it started. its only in the starting sequence that theres a problem. i also switched to new dual carbs with Y splitters. i just dont get it. maybe back to trying to clean every connection point. or rewire the bike.

 

When you say "won't kick over" do you mean it won't crank at all? Or is it cranking but not starting?

Maybe just a flaky starter solenoid or starter button contact. Does the solenoid click when it won't crank? When it won't crank, have you tried jumping directly across the two big terminals on the solenoid?

 

So it wont start. it always turns over. ive tried jumping the solenoid. same things turns over but wont start.

 

Have you pulled a plug wire and confirmed that there's no spark when it's cranking but not starting?

 

Fuel, air and spark is what you are looking for. You have it turning over. The emergency cut off switch on the right bar is in the "run" position. It was running but now is not. Original fuel petcock? I would turn it to the PRI or prime position, wait a few mins and then try again. If that does not work.

Remove the air cleaner and spray some starting fluid or brake cleaner into the back of the carbs. If the bike tries to run, then you have a fuel issue. Either the petcock is not allowing fuel to fill the carbs or the carbs are dirty and need to be cleaned. Don't get overwhelmed by troubleshooting, break it down to simple things and step by step. If the petcock is working, make sure you have a good open fuel line so fuel can get to the carbs. We had that issue a few weeks ago with one bike.

Keep us posted on how it is going and what you have found out.

 

So original Start Switch is no good. Took it out. all together, No kill switch at the moment. just a starter button. Also got rid or original carbs. Now Murray carbs. So no airbox. Carbs brand new. Bike didnt used to run until i switched carbs. THe bike runs great when i do get it started so not a fuel issue. Diffidently electrical. when i do turn prime on i always see it drain into the bowls so i know that fine. I have an inline filter in place so i see it moving. im double checking wires and grounds now. I really think thats the culprit. Drop in voltage when starting.

 

I will double check for spark but im pretty sure its electrical and not fuel.

 

OK here's the update. I have spark!! all 4 cylinders. So i checked the carburetors they are clean as a whistle which i expected since they are new. I also put it up on kicked stand. double checked the level as well. So if i have spark and i have fuel, i left the prime on and it overflowed the way its supposed to once full so i know bowls are getting fuel. I see spark on outside of cylinder. SO what gives other than no strong enough spark? it runs like a champ when i do get it started. no compression issue.

 

Starter jets plugged? After you do get it running, does it respond to the choke lever? Will it rev up to 3500 or 4000 with just the choke?

Being out of sync can make for hard starts also, and that can largely be masked at higher rpms.

Also, nothing should overflow on prime. Was it dumping fuel out the airbox? Float needles not sealing doesn't necessarily explain not starting, but you might be chasing a couple issues here. But maybe it's flooding when it sits, then you finally crank it enough to clean it out.

Maybe check for wet plugs or gas smell when it's in that condition of cranking and not firing.

 

Bike responds to choke lever when running. because i turn off choke after it warms up and bike rpms come back down to normal.

Left side wet plugs right side dry with no start.

ill look at carbs again. these are Aftermarket Murray carbs, was 4 carbs now 2 split by Y valve