My 06 had been sitting on the floor so long that they couldn't resurrect the battery at all. They finally delivered it with a new one out of their stock.

Interesting conjecture about low battery meaning rough running. Somebody the other day suggested that the charging system won't produce 12 volts at low rpm. And if the battery is weak, there you go.

 

My 06 had been sitting on the floor so long that they couldn't resurrect the battery at all.

A new battery that has only had it's initial factory charge lasts about 9 months. After than the battery is effectively stuffed and should be replaced because it will never hold charge correctly.
Once a battery has been charged again either by having the bike running or by using a charger of some sort you are pushing the envelope to leave it any more than 6 months without a further charge.
If anybody is buying a last years model bike cheap from their dealer they should always check the age of the battery or the manufacture date of the bike. If either is more than about 9 months old insist that the battery is swapped for a new one as part of the deal.

 

The fuel pump needs 12 volts. I killed my battery one day, thanks to the lovely parking light "feature". I got it jump started and watched my volt meter all the way home. It never got to 12 volts and the motor ran crappy. I put it on the Battery Tender over night, it charged to normal and ran just fine. I bought a new battery anyway, which holds its charge much better.

 

That's for sure.

 

This makes me curious - would a low voltage condition cause issues with a throttle body sync? I never seem to be able to get the manometer to stay level ...I get it adjusted and level, turn the bike off, turn it back on, find the levels off by several inches again, adjust, off/on, and they are off again. (FYI: I tried tracking to see if it was favoring one cylinder - no trends to report.) Is the inconsistency related to low volts?

 

Hollaback: I do not see how low volts could affect the throttle synch. One thing to remember if you are using a home made manometer filled with oil: an oil filled manometer is much more sensitive than one filled with mercury. Plus if you are using a differential manometer (each end tied to the bike vacuum) that doubles the sensitivity again. So a couple of inches differential with oil is probably well within the vacuum tolelrence that was enviosioned by the design engineers.

I had a thought about the comment that the generator did not put out enough volts at low RPM. When I put my new battery in, I did not find this to be true. If you have a weak battery, it will load down the charging system and only show whatever voltage the battery is able to hold on its cells. In my case, one cell shorted so that battery was stuck at 10.2 volts and thats what I read with my meter on the battery while the bike was running. By way of example, if you put a wire short across the generator, it would show 0 volts but there would by lots of current flowing in the wire.

 

Hollaback: I do not see how low volts could affect the throttle synch. .

it wouldn't affect existing syncronization, but if yer trying to sync it while the fuel pump is running like crap, you'd probably get a crappy sync

 

The previous owner put one of those handy dandy little LED voltage indicators on my bike. It shows an undervolt consistently at idle speeds..I figured that was normal, but now I'm worried.

Imma stop reading these threads! :sad1:

 

If you want to be sure, buy or borrow a real volt meter and see what voltage you get vs RPM. Probably no need to go much higher than 2000. At absolute low idle, the bike may be running off the battery. But you should see 14 volts with very little throttle. Remember that there is a lot of current draw from the lights even at idle. You can calibrate your LED meter that way so you know what "low" really means in terms of voltage. Then just look for changes over time. Also pay attention to how your starter motor sounds. If it sounds slow, the battery is on its last legs. In the old days you could test the fluid in each cell of the battery. Now that the batteries are sealed, you can't do that. I don't have too much faith in shop-type battery testers. I have had part store guys tell me my (car)battery is fine when I knew from how it worked that it was not fine.

 

There are a number of threads here about uneven or rough running at low RPM. Symtoms include missing, surging, backfiring, etc. The usual suggestions are TBS, fuel mixture changes, etc. it was an 07, I am guessing the battery and the bike had been sitting around for sometime.

I don't know about the battery deal but I do know that I'd kill for that KR z that you used to own!!! I've been looking for that bike and a RG500.

jeff

 

Jeff,
I don't know about the bike but I'd kill for the girl in your avatar

 

The DL CPU monitors battery voltage, and compensates its sensor readings accordingly. So, in theory, that shouldn't be a problem.

Now, the fuel pump, on the other hand, could certainly be a cause of poor running at low system voltages.

 

Voltage vs RPM

In the next day or so, I will measure the voltage vs RPM at the battery and post the results. Just because I can.

 

voltmeter - trust me, you need one

IMO riding a Suzuki without a full time voltage monitor is just asking for trouble. In general Japanese charging systems suck and I think Suzuki is the worst of the bunch. I know 3 or 4 SV owners (including me) who have suffered failures - usually rectifier/regulator failures but those often lead to bigger problems. One friend fried ALL his electronics when his VR/R failed with overvoltage. It was VERY expensive to fix. He used junkyard parts but new stuff would have been well over $1K.

I have a Datel digital voltmeter mounted down inside my faring (behind the headlights) on my 650 and it keeps a constant monitor on the system voltage. Since this is the DL1K forum let me say that the 1K has only slightly more generator capacity than the 650. The 650 is in discharge at idle. With no electrical farkles turned on mine will be charging at 14.1 volts by around 2500rpms.

People running auxiliary lights really put a load on these bikes. There's only 100 - 150 watts of unused power - a couple of extra H4s will eat that right up and you'll be only be charging at highway speeds. You really DO need a voltage monitor whether it be an actual voltmeter or one of those little LED devices particularly if you have extra electrical loads installed.

 

I had 2007 r1 that was running rough changed plugs check coils and changed coolant because I thought it was happening worse when stuck in traffic it even went down to running on three cylinders once ended up the battery was low it was the regional battery Yamaha change it and runs perfect now and the mechanic told me that the 07-08 low battery can affect the engine.

 

In 1980 I purchased a Kawasaki 250 triple for $50 (kick start only), it was cheap because it would only run on 2 cylinders.

While fault finding I discovered that if I hooked up a second battery with jumper leads the thing ran like a dream.

I loved it as a toy to play on but the bride was not impressed, I turned it into a café racer and because of the single seat she was on the bus. :yikes:

 

Interesting thread- a few days ago the battery in my Vee died unexpectedly.
But now that I read this thread and think about it- it did seem to run a little poorly a few times, at low speeds, lean surge I thought, and I sort of wondered if my PCIII quit working.
I now wonder if that was a clue the battery was going....I rode 100+ miles after a new battery and noticed no issues.

 

I haven't owned my Vee long enough to say but I owned a 2002 TL1000R for a few years.
I noticed that having a fully charged battery made a BIG difference on the way it ran. Especially in the lower RPM range/ idle.
If the TPS wasn't getting a full, healthy, constant 12V she would run pretty lumpy.

 

Thanks for that i just bought a gsxr600 today [ 96] and took out the battery it was really low the revs were sluggish / weak at 2-3k revs . I will take the bike out tomorrow see if that helped .

 

My 2 cents: I also ride a Madura GV1200 and those bikes don’t like week or incorrect batteries. I was on my vstrom a couple of weeks ago and it just didn’t feel the same as the day before. This was a 2500 mile trip. The day before I was in stop and go traffic and would shut it down when stoped until it almost didn’t start. After getting back to camp it started fine so I thought all was fine. Next day was highway travel but when I got to a town I stoped to talk to locals. Bike wouldn’t start. Let it cool and it finally cranked & started. Off to the closed dealer that had an parts store next door. Borrowed a volt meter and only 12.5 v at 2500 rpm. I freaked out thinking charging system. Pulled battery and had it tested. Tester said REPLACE BATTERY. 1.5 yr old AGM. I installed a new one and charging voltage was now at 14.4 v. I was happy, the bike seamed to run better.