Hard to start

[TitanNeil]

My '83 GS1100GK is a bear to start. Once warmed up it runs great - but from cold I either kill the battery or need several shots of 'quick start' to get it to fire. I thought initially it was a fuel/petcock problem but now I think it is weak ignition. The bike has a new reg/rectifier, spark plugs and caps but all else is original.
Brought the bike out of storage, slapped in the (charged) battery and it basically drained the battery in 10 seconds. I put the voltage tester on the battery (12.57V) at rest, turn the key on and it drops to 10.5 and keeps slowly dropping from there. Hit the start button for 5 seconds and it goes to 6V then 4V as I watch. At this point the motor won't crank over. Is this battery cooked or is there some serious drain on the ignition? I am an electrical potatohead but can wield a multimeter, somewhat hamfistedly.
Advice on where to start?

[Ranger]

Did you hook up cables from your vehicle with it off and try to turn it over?

[TitanNeil]

If you mean using a car battery or other battery to start it, then no. I struggled with this hard-start problem last year, using an extra motorcycle battery that I kept charged up just for this reason. Even with a jumper battery it didn't like to start from cold.

[Ranger]

Might as well try using the car to jump it to eliminate possible causes.

[tom203]

Did it have this same problem before it went into storage? Your battery is probably shot from your description- did you charge it from time to time? Doublecheck for basic petcock operation by pulling off fuel hose to carbs, hold cup under petcock and switch petcock to prime- you should have decent fuel flow. Visually check that choke cable is doing its thing and hasn't froze. Lose the "quick start" unless its 20 below !

[TitanNeil]

Last summer I fought these same battles - rebuilt the petcock to eliminate that possibility (works well - good gas flow). It always came down to battery and spark. I have substituted 2 other known good batteries to no effect. Although it does spark I think it must be weak - i've started reading BassCliffs stator papers and ignition troubleshooting columns to see if there are a few test I can do. The bike is outside and although it is now 10C and sunny, its windy as hell so that makes it no fun to troubleshoot.

[BassCliff]

Hi,

Have you cleaned all of the connections in your wiring harness? Too much resistance in the circuit causes major voltage drops. What is the voltage at the coils when you try to start? While you're cleaning all the connections and grounds, include the fuse box and ignition switch.

When is the last time you adjusted the valves? Click HERE for the full maintenance lists.


Thank you for your indulgence,

BassCliff

[azr]

If it's a hard start cold doesn't that lead to problems with the choke system as well? Cliff is right about checking your coil voltage, easy thing to cross off the list if it's at least 11 volts. Check your coil primary and secondary readings to rule out the coils. Although if the bike is starting fine when it's warm and running fine once it's warmed up that sort of rules out any electrical problems. If it continues to start fine once it is warmed up that rules out any problems with the battery. This sort of leads back to the carb issue. When was the last time the carbs were pulled apart, dipped, cleaned and rebuilt?

[TitanNeil]

Last summer was the first time I had this bike on the road - it had sat for at least 4 years outside before that (no, not my doing!). I cleaned what grounds I could find (not many), stripped & cleaned carbs, replaced intake o-rings, adjusted valves. For a while I had issues with fuel that a rebuilt petcock seemed to solve (2nd cylinder flooding). I blew the main fuse on a 45min trip but had a NOS voltage regulator with me so problem solved there (old one had burn marks and corrosion on the back). Sometimes it would pop a bit out the exhaust when I got it started and was warming it up - it ran fine when warm. I think BassCliff is right - I need to go over the harness connections and clean them up, and test voltage at the coils especially. The spark always seemed quite minimal there. Going to pick up spare battery now so I can at least have it ready to test.

[posplayr]

This is a simple test to start with when you get closer. From your previous description the battery was very dead. No way to pull a good battery down to 6V without pulling a bunch of current which would smoke something.

Want to just get a feel for how the charging is working? Do a Quick_Test

Once you get a better battery and you do the quick test and everything is OK , make sure that the voltage at the coils with the key on is above 11.0V (as a minimum). Connections can get dirty in the ignition switch and connectors and you need a coil mod relay to get around this chronic problem.

On my ED with new harness, new battery and full rebuild top end my bike was hard start and needed a spritz to get started cold because coil voltage was about 10.5V v.s. 12.8V at the battery. Coil relay mod ended all that.

[TitanNeil]

I've come across some wiring problems that will effectively sideline the bike until i've gone over the whole thing. The 3 cloth-insulated wires from the stator (yellow, green/white, etc) are crispy and green with corrosion. The plastic insulators are falling apart and one wire broke off in my hand. Ouch.
I'm amazed it still charged.
Voltage at the coils is 10.8 and 10.9 - not great. Spark at the plugs is weak and yellow.
I think I have some work ahead of me....tomorrow i'll get the soldering gun out and replace wiring.

Thanks for all the help everyone!

[Steve]

Good thing you mentioned that you had adjusted the valves.

The FIRST thing you need to do is replace your battery. To confirm that, connect jumper cables to your car, ENGINE NOT RUNNING, try to start the bike.

Of course, this assumes that you have primed the carbs and used the "choke" properly. NOTE: using the "choke" properly means that you do NOT use the throttle at all while starting the bike. You adjust the idle speed with the "choke" lever.

As you will find in posplayr's "Quick Test", your battery voltage should be over 12.5 before turning on the key. It should stay over 12 when the key is on and should remain over 10 while cranking. Your super-low readings indicate a dead battery. Try charging it, but it's likely in need of replacement.

.

[TitanNeil]

I picked up the fully charged 'spare' battery and it managed to hold at 11.3V while cranking. I could crank it a few times and the voltage would bounce back to 12.35 or more if I waited a minute - so that battery is good, while the original ist kaputt. Still has weak spark though, and with corroded/broken stator wires and cracked plug leads it is time for a thorough electrical go-through. I have a friend with boxes of NOS Suzuki stuff in his storage, i'm going to see if I can dig out some new coils.

[TitanNeil]

Well, now i'm frustrated.
I went throught as much of the wiring harness as I could, including cleaning out the thumb kill switch and the clutch cutout switch. Clipped the cracked ends of the coil leads and put new caps, cut the corroded connectors off the stator leads and soldered them up permanently. Spray-cleaned as many of the connectors and connector blocks as I could find, cleaned the connectors to the coils, cleaned engine ground strap on the bolt and recharged the battery. After a few minutes of fooling around with 'Quick Start' and a 2nd battery jumered to the first, it started. Popped, crackled and finally smoothed out enough to run on its own after a bit. I was getting 11.2V at the coils - with all the cleaning it went up by 0.7V so I must have done something right.


Measured across the battery: 12.3V at idle, and 12.05V at 3500 RPM. Crap.
Just for fun, I went and got my helmet - but to no avail, as the bike would not start again, and I ain't lugging the 'start spray' and jumper cables and spare battery out for a ride.

Did I miss something obvious?

[BassCliff]

Hi,

I think it's time to go through The Stator Papers, testing the output of your stator, etc. You might also want to think about installing the coil relay mod. Did you clean up the fuse box while you were cleaning up the wiring harness?



Thank you for your indulgence,

BassCliff