Keeping revs above a certain level? How many starts do you get?

[Spiff]

Hi all,

I've got a heap of questions to ask mostly related to constant issues I have with starting the bike from cold or if not ridden for a few days. I've seen Kamahl & Gavin, know that the starter motor has two worn brushes, had a new batt 6 months ago, the batt is in good condition (checked with multimeter), changed my own fuel lines, had the following done "alternator windings", "regulator/rectifier" (i'm guessing these were replaced?), and just had the carby cleaned and rebalanced last week.

The bike is a 1995 Suzuki GSF250 Bandit.

Anyway, I'm wondering how many times one usually gets out of the electric starter? I usually get one try. Sometimes two. If I can't get the bike started by then, it's 20mins of bump starting for me. At present, to get it started in one go (if it's morning or not having been ridden for 2-3 days), I have it on full choke. Start it and immediately rev it up high (~6-7rpm) for at least the first 5seconds. If not, it'll almost immediately die. If I feel it's going to die, I have to rev it a bit. I'm assuming this is pushing fuel to the engine?

The second thing is, I noticed for a period when riding that the fuel gauge indicator would just go to 'E'. I originally thought this was because of a poor connection, but after a few months, I noticed that if I kept the bike revs at 6000rpm - i.e. riding it semi-hard and not shifting up too early, the gauge would work properly. I've read that sometimes you have to keep bikes above certain rpms so the battery can be charged. Is that right? Being my first bike and having decades in cars, my habit has been to shift-up to keep the rpms low and save on fuel.

Anyway, I'll start with this for now. Thanks.

[Frogger]

a zzr250 doesnt seem to start charging the battery untill past 5000rpm . u might need to adjust your idle if its to low the bike will stall without applying throttle .

ill normaly sit at 8000rpm on my zzr250 as thats where its most zippy

[96]

New battery if the gauges are playing up....

[Spiff]

cheers frogger. when it's warmed up and running, it's ok. it's just the first start of the day, or if the bike hasn't run in a couple of days..almost certain that without applying throttle when i start that it won't stay running.
my gsf250 has 6 gears and i find the most power around the 7-10000 rpm range, but i can go along quite happily on 6th gear, 60km at just under 6000rpm...except if i do that, it usually means i'm changing a gear up before it reaches 6k, so i don't know if it's the same as yours where it has to reach 5000 to charge. i can't seem to find a lot of info about it cos it's an older bike.

@96, only the fuel gauge..speedo n tacho are fine. i think it's more likely not charging at <certain rpms. plus batt was bought new around 6 months ago and was tested last week.

anyway, how many attempts do you guys get with your electric starters if it doesn't start first try, everytime? next bike i get is gonna have efi by golly!

[Falcore]

Speedo won't require power to work as most likely cable driven in this case.

Check your charging circuit, I generally get 3-4 goes easily at starting the 1098 (probably more but always starts then) an probably find the battery is similar.

If your battery isnt very old definaetly check your charging circuit ASAP as you may fuck a perfectly good battery if you don't.

Sent from my HTC Desire using Tapatalk

[IvanM]

definaetly check your charging circuit ASAP as you may fuck a perfectly good battery if you don't.

What Falcore said. There might be some wiring damage on the charging circuit.
That damage might contribute to no charging current going back to the battery if the current is "weak". By revving higher, you increase the "strength" of the current so it will flow through some damaged wires, thus charging back your battery and making your fuel indicator work properly.

[Rich]

So Kamahl and Gavin have checked the bike over?

They had no issues with it starting?

You should be getting more than two goes from the battery...

I would suggest checking your earths, make sure they are all clean and tight, and that the earth lead from the battery is in good condition, they corrode internally...

The other thing is your starting regime, maybe you are flooding it a bit by using full choke...

[Veefore]

How old is the battery?
It sounds more like the death throes of an old battery rather than a charging system issue to me.

[Spiff]

battery was bought 21/1/11 at gavin's recommendation cos he helped me give the bike a once-over before i bought it, and i left it with him for about a week to get a thorough check and service. at the time, he noticed there were a couple of worn brushes and said it would still be ok and to give hiim a ring if i got sick of bump-starting the bike. anyway, that was in summer.. i had to bump-start it less (fewer cold mornings?). also, back then, i noticed the issue with the fuel gauge going down after i started riding it first thing in the morning..it would drop to 'E' as i left the driveway, but if i gave it some..and got it to around 6-8k rpms.. it would then slowly work itself back up.

anyway, winter comes, gav's busy, so i've sent my bike in to ktec for another service and while kamahl's replacing the carby gasket, he also cleans out the carby and rebalances it for me. that was last week. i tell him about the problem and he checks the battery with his multimeter. he tells me the batt is in ok condition but thinks it might be some charging issues, but that's not the main reason i've gone in to see him, so we leave it as that.

the thing is when the bike has warmed up, i can usually get it going ok. the electric starter still only gives me about 1 decent start, and a second slightly weaker start if i don't do it right the first time. i only use the choke for the first start of the day. so, the point is, by the time i ride to kamahl's or gavin's place, the bike is warmed and even after servicing, they can get it started without the issues i face from leaving the bike sitting overnight.

i'm unsure how to check the circuit and i don't have a multimeter anyways. gah!

@rich, kamahl mentioned my starting regime as well, and when i had to bump start it on fri night, i tried not giving it any choke and not revving as i was try bump-starting. not sure if it's a psychological effect, but that didn't seem to work any better..but when i went back to leaving the choke on full, running with the bike, hopping on and popping the clutch while revving it a little and using the electric starter to help it a along, it seemed to work a little better and eventually (~10runs with the first method, ~5 with the second) got it going. then again, the first 10 runs might have helped it a little.

now i'm thinkin if there's a cost effective way of being able to learn how to try and diagnose the problem (save the pro some time+myself some money)..or whether i've to bite the bullet and send it in to a pro to get it looked at in detail. i've prolly spent more than one should for a 250, but i do like having problem-free starts

[Veefore]

I'd still chuck a known good battery in to test. This is always the first thing I do anyway. It may be that your charging system isn't keeping up and is slowly killing the battery anyway. By your last post it does sound more like the bike is using more battery than the charging system can replace.

[Crobbo]

So have you always only been able to get 2 starts from the battery?
Have you got a battery tender you can charge it overnight with?

[Spiff]

So have you always only been able to get 2 starts from the battery?
Have you got a battery tender you can charge it overnight with?

yeah.. am pretty sure it does.. cos it sure does help the bumpstarts when i pull the fuses out for the rear and front lights (there's no on-off switch for those). i used to have a battery tender..but it was overkill, guess it's time to get another. if i've not ridden it for a week (0 starts), if i've not ridden it for 3-4 days (1 start), if i've not ridden it overnight-2 days (1-2 starts).

edit..sorry, overkill meaning it was meant for my car, but not the bike, so i sold it.. i haven't bought one with a lesser voltage.

[Crobbo]

What voltage is the battery? You mentioned a lesser voltage battery tender, could it be you got a 6v battery in a 12v system.

Not sure if a 6v battery would even start a 12v bike though.

[Spiff]

What voltage is the battery? You mentioned a lesser voltage battery tender, could it be you got a 6v battery in a 12v system.
Not sure if a 6v battery would even start a 12v bike though.

it's a 12v - Roadstar YTX7A-BS AGM. What I meant was the charger I used to have was a Ctek XS7000 that would charge at higher than the 6Ah recommended for this battery. I emailed Ctek and they recommended a smaller charger, so I sold the XS7000. I don't have any chargers at the moment, but have one on the way.

[Spiff]

By the way, when I start the bike for the first time in the mornings on full choke and no throttle (per the manual), it fires up fine..then after it hits its peak starting up, the engine just dwindles down and dies. That's why I have to give it some throttle. According to the manual, I shouldn't need to have any throttle. Is it just because it's an old bike? And is this related to the electrics/battery? Or is this a fuel/air issue? (this is only the first start after being left overnight. if i've ridden it around, parked it, come back during the day to start it to ride home, it's fine).

[Rich]

Ok...it does sound likes it's flooding...

When it starts, ease the choke back off...

You may find you are better off starting on 3/4 choke...

[Spiff]

rich, do you mean i'm flooding it with fuel? i'll give that a go in the morning (haven't ridden the bike today). i'll try 3/4 choke, but with a bike this old.. sometimes it feels like there's not so much sensitivity in the choke. it's like i can go from zero to half to full..finding a 1/4 or 3/4 isn't going to be 'perfect'..but i'll give it a shot.

if i'm accidentally flooding it with fuel, does this work?
"If you put on the choke or enriching circuit and find that you have put too much extra gas into the engine, flooding it, you can clear the engine by opening the throttles wide open and cranking the engine. This creates a zero vacuum condition in the throat of the carburetor. That means only air, and no gas is drawn into the engine. This, in turn, will clear the excess gasoline out of the engine". Dan's Motorcycle Starting a Motorcycle

also, it says i put the choke on only after turning on the ignition. question is, if the ignition is not on, does anything happen if i turn the choke full/off/full/off or throttle full/off/full/off? not that i do it, just wondering.

[Rich]

You can play with the choke and throttle to your hearts content when you are not cranking and no fuel will go through...Carbies with an accelerator pump will throw fuel in when using the throttle with out the engine going...your bike doesn't have an accelerator pump...

What I believe is happening is the full choke is giving too rich a mixture, it starts but then floods...

When you hear it starting to stall you open the throttle full, allowing air in to lean the mixture out...engine keeps running...

I suggest trying different ways to start the bike, till you find a system that works...

I still think you probably have some starting system problem too, as you should get quite a bit of cranking from a full battery...doesn't sound like you are...

[Spiff]

yeah. you've hit the nail on the head i reckon. anyway, it'll take some time to sort through the starting/battery problem as i try to figure out how to troubleshoot the issue using the ideas here.
will give the starting methods a go beginning tomorrow. i've never really tried it because i've not got a clear idea of what does what, when i open or close it. anyway, i've got a rough idea now.

[IvanM]

...then after it hits its peak starting up...

What do you mean by that?
Do you mean that just after you start and the revs increase and doesn't stay up (even with full choke)? If this is the case then the choke is not working.

Or do the revs stay high as you leave the choke fully open? If this is the case then Rich's explanation is probable.