Difficulty starting ... need opinions please!

[Guest]

Hi All!

My 83 GS1100G has always resisted starting when cold, and even when warmed up the starter motor will strain to restart the bike under certain conditions. Initially I thought that the starter might be binding, or that the electrical connection from the starter relay might be the culprit, but Skreemer, Nerobro, and I checked the wiring (as well as jumping the starter directly from a fresh 12V source) and found no problem there.

I have discovered over time that if I don't use the choke and don't twist the throttle the engine will turn over VERY slowly and resist starting, BUT if I choke it completely (even when warm) and twist the throttle very slightly the motor turns over freely and generally starts pretty easily.

It was suggested that poorly synced carbs could cause this situation, and that by twisting the throttle I am eliminating an uneven vacuum issue. The bike seems to idle and perform pretty well when it's running, so I never considered a carb sync to be a possible solution here.

Now that I've bored you all with a long description of the problem, my question is whether anyone else has experienced similar starting problems and whether a carb sync solved it. Also, is there anything else I might be missing? The previous owner of the bike told me that he had replaced the starter at least once or twice with no improvement in the starting routine, so I'm doubtful that the starter motor itself is faulty.

Opinions are appreciated, and thanks in advance!!

Steve 8)

[joeadams]

This sounds about like what Mine is doing. Except mine is only like this when its at operating temperature. The more it cools, the better it cranks. I have no real input but I'll be very interest to see what people think of this one.

[isaac]

If the r/r is suspect at all, replace it with a honda one. That was the final piece in the puzzle which may have cured my bike's extremely hard starting.

Other things I did which led to fixing the hard start:

New plugs
Synched air screws at back of carbs to raise idle, then lowered idle with main idle screw in between 2-3 carbs.

If the starter cranks slowly, it won't start the bike very easily. If you can push start the bike and it fires after the first or second push start, then your starter or battery is probably the problem. Make sure the r/r is taking care of business though. It was really screwing up my bike, and it didn't check out bad with wire to wire tests, but only put out voltage in the mid 13's, which kind of clued me in.

One more thing: Those fixes jacked my mileage from less than 25mpg to more than 33mpg.

[Nerobro]

Beyond just cranking slowly, his engine cranks over in a very unhealthy manner. (I was there today..) The starter works great when hooked directly up to a battery. The entire voltage drop between the battery and the starter is .05v. Yes his battery was weak. But when hooked up to a strong, larger battery it still cranked over with a very ill sounding lope.

The lope is (in cars at least) caused by one or more cylinders having vastly different compression than the others. Usually caused by failing rings.

When the throttle is opened. just a little. The differences in carburator ballance is negated. And then the engine cranks normally. Slightly slowly. But completely normally. Now the starter on the bike has been throughly abused. Holding a DC motor near stall causes HUGE amp drains. And I'm willing to bet that that "g" will need either new brushes, or a rebuilt starter sometime. (Yes, I know it's the third starter...)

oh yes, on the RR question. The bike had what was effectively a flat battery. 15 miles later, the battery was at 13.5ish volts at rest. (it's an older possiably toasty battery) And during the whole ride, all the headlights and signals functioned at a steady rate and of steady brightnes.

Wow... i've been awake for 22 hrs now. I should sleep.... I have a 550 to get back on the road tonight. God I with my bike were all working... but that's for another thread. :-)

[Planecrazy]

Beyond just cranking slowly, his engine cranks over in a very unhealthy manner. (I was there today..) The starter works great when hooked directly up to a battery. The entire voltage drop between the battery and the starter is .05v. Yes his battery was weak. But when hooked up to a strong, larger battery it still cranked over with a very ill sounding lope.

The lope is (in cars at least) caused by one or more cylinders having vastly different compression than the others. Usually caused by failing rings.

When the throttle is opened. just a little. The differences in carburator ballance is negated. And then the engine cranks normally. Slightly slowly. But completely normally. Now the starter on the bike has been throughly abused. Holding a DC motor near stall causes HUGE amp drains. And I'm willing to bet that that "g" will need either new brushes, or a rebuilt starter sometime. (Yes, I know it's the third starter...)

oh yes, on the RR question. The bike had what was effectively a flat battery. 15 miles later, the battery was at 13.5ish volts at rest. (it's an older possiably toasty battery) And during the whole ride, all the headlights and signals functioned at a steady rate and of steady brightnes.

Wow... i've been awake for 22 hrs now. I should sleep.... I have a 550 to get back on the road tonight. God I with my bike were all working... but that's for another thread. :-)

Greg,

I appreciate your attempts to add more information here but unfortunately you're just adding unnecessary confusion. Let me clarify a few things:

First, the battery WAS in need of a charge yesterday (First run of the year) but Greg was wrong in guessing that it's an old battery ... to the contrary, it is almost brand new (bought last summer) and works perfectly when fully charged. Several hours after charging the battery cranked and started the bike with no difficulty whatsoever (with choke and slight throttle, of course).

Second, the engine also turns over normally and perfectly when the battery is fully charged if I choke it and slightly twist the throttle, so I KNOW the starter motor is also working perfectly -- again, Greg is mistaken in guessing that the starter motor has somehow been "abused." Also, the extra battery we used to directly test the starter was in need of a charge itself, so Greg's assumption that the starter might be bad is based on incomplete information. Yes, Greg, it's time to get some "shut-eye!"

Third, Although I have not gone through any charging system tests I am VERY confident that it is working properly, as it not only charges the battery reliably when the bike is regularly run, but I also have my fairing lights set as running lights (always on) and sometimes use accessories from my lighter socket with no negative effect on running/charging.


So again, to restate, it would seem that the problem has something to do with abnormal vacuum or compression. Any thoughts along these lines will be helpful, thanks! Oh by the way, credit where credit is due ... it was Nerobro and Skreemer who first suggested that the problem might be vacuum/compression related, which makes sense given the circumstances -- thanks guys!

Steve 8)

*edited for typos

[Jethro]

It is amazing how much difference a carb synch makes. I didn't believe it until I finally made the plunge and bought a nice carb synch gauge. I'm not sure if it will solve your problem, but it's worth a try.

Have you added a better ground to the RR? I installed a big 10 gauge ground wire directly from the RR to the battery terminal. Again, not sure if it would help or not, but worth doing.

[Planecrazy]

Have you added a better ground to the RR? I installed a big 10 gauge ground wire directly from the RR to the battery terminal. Again, not sure if it would help or not, but worth doing.

Interesting idea, but in this case I don't think the charging system is at all related to the problem, as it has always worked flawlessly.

I think I'll have to get together with the Chicago guys who've had experience with syncing and see how far off mine are and whether the sync solves the hard starting issue.

Thanks!
Steve 8)

[Nerobro]

*crawls into a little hole* :-) I had been up for way to long. Sorry ;-)

[first timer]

hmm a couple things you say it kinda turns over slowly or it takes a long time for the motor to fire up (the starter keeps turning and turning then fires up)

it could just be a bad battery, it has enough power the first rouvolution but is drained on the next revolution causeing it to turn over slower. how old is the battery, just go buy a new one, that way you know it;s not a bad battery.

next clean all your ground connections and other connections.

you can also pull all your plugs and turn the bike over that will let you fully see how you starter turns under minimal load, as well as test your battery.

next you can check your shims, you have a 8v motor and your shims could be causeing odd compressions in the cylinders.

check you clutch maybe it is draging while the motor is spining.

all the above address the speed of the motor as it turns over

if the motor is able to turn over at a steady speed in a time span of 2 minutes (that about how long a healthy battery willl be drained) then you may just have dirty carbs and some old spark plugs, if you have never cleaned the carbs youself then it time to clean them!
after cleaning we will work on syncing.

if you have a healthy easy spining motor with fresh plugs and fresh gas and clean carbs your bike will start on the second revoultion mark my words if my 1000 can do it, and thats in lot worse shape then your 1100 your 1100 can do it to.

-ryan

[Planecrazy]

hmm a couple things you say it kinda turns over slowly or it takes a long time for the motor to fire up (the starter keeps turning and turning then fires up)

it could just be a bad battery, it has enough power the first rouvolution but is drained on the next revolution causeing it to turn over slower. how old is the battery, just go buy a new one, that way you know it;s not a bad battery.

next clean all your ground connections and other connections.

you can also pull all your plugs and turn the bike over that will let you fully see how you starter turns under minimal load, as well as test your battery.

next you can check your shims, you have a 8v motor and your shims could be causeing odd compressions in the cylinders.

check you clutch maybe it is draging while the motor is spining.

all the above address the speed of the motor as it turns over

if the motor is able to turn over at a steady speed in a time span of 2 minutes (that about how long a healthy battery willl be drained) then you may just have dirty carbs and some old spark plugs, if you have never cleaned the carbs youself then it time to clean them!
after cleaning we will work on syncing.

if you have a healthy easy spining motor with fresh plugs and fresh gas and clean carbs your bike will start on the second revoultion mark my words if my 1000 can do it, and thats in lot worse shape then your 1100 your 1100 can do it to.

-ryan

...All good suggestions, Ryan, but most were already addressed by my description above.

Now, with regard to your carb clean and new plug suggestions, here's my question ... Wouldn't the bike be running poorly if either of those problems existed? The fact that it idles and runs well throughout the rpm range leads me to believe that both the carbs and the plugs are in essentially good shape...

I would think that a the carb sync would be the most likely solution that I've heard so far, with the possible exception of adjusting the shims (which I haven't done, but was told by the prior owner had been done).

So now I have two logical sounding solutions on my list ... carb sync and shim adjustment.

Thanks for the input!

Steve 8)

[Planecrazy]

oops, internet trouble -- double post...

[Anonymous]

Is it by any chance to far advanced and bucking the starter? Being too far advanced often results in other more serious problems but it might be worth disconnecting all the plug wires and seeing how it cranks then. If it cranks better, it is too far advanced. If it cranks the same, scratch that entire idea off the list.

[Planecrazy]

If it were advanced too far why would it turn over easily and normally when I apply the choke and very slightly twist the throttle? Also, too much advance would presumably affect the performance while riding, and I never experience any obvious performance issues when I'm actually riding.

I don't think there's a connection but thanks for offering up another possibility!

Steve 8)

[earlfor]

Steve, I think it is an induction/compression balance problem. Normally, one does a compression check with the throttle at wide open. Just for the hell of it, I would remove the spark plugs and take compression readings not touching the throttle. I suspect that your slides in the at rest position are very different and out of synch enough to cause uneven compression. If you have VM carbs, they are throttle priority and twisting the throttle will raise the slides manually. If you have CV carbs, twisting the throttle will have no effect on slide position prior to starting the engine.

I think you need to check your valves and do a carb synch.

Earl

[Joe Nardy]

Steve,

First of all, I have to agree with Earl. He's hardly ever (never?) wrong. Then I think it would also be worthwhile to install a relay that shuts off the headlight when the starter button is pushed. This makes an extra 55 or 60 watts available for the starter motor. Also, installing a relay that bypasses the ignition switch will give you an additional volt or so for the whole electrical system. I installed both of these relays a couple years ago and my bike has never turned over better.

Joe