What does your voltage read when you turn on bike, key only, prior to starting? I’m attempting to diagnose a weak starting issue that reared its head right after discovering a shorted wire that was blowing fuses. I’ve fixed the shorted wire and wanted to know if I caused irreversible damage to my battery, and if this is the reason my bike now struggles to start sometimes.

It seems that when the on dash voltage reads close to 13.5V, it cranks up instantly. If and when the battery voltage reads low 13’s - high 12’s, it struggles to start and only starts if I hold down the starter button longer than usual.

Thanks

sorry, no Shorai... but perhaps this helps a bit?

this morning's turn key voltage display = 12.2 V
while being on the move, display says 14.4 V
am having a 2½-year old YUASA YTX14L-BS battery
... ambient temperature here currently @ 30 degC

At least 12.5v, less than that, it's going to have to crank over a couple more times. 11v, it probably won't start and if it does, you'll get an explosion out of your muffler. If your battery dropped to 11v or less, there's a good chance your Shorai battery won't hold a charge as well as it did before that. It will still last years but you will have to keep it on the charger between rides. It gets worse as it gets older. Mine lasted 11 years but it had to be kept on a charger. It held a charge sufficient to start the bike for two or three days towards the end.

Thanks guys! Been chasing down this sporadic cranking issue for over 2 weeks. I changed out the stator and rectifier, purchased a AGM battery and returned it after I discovered that the issue still existed. Now that I eliminated one area, electrical, and the issue still existed… that left only 2 areas I needed to explore…fuel and spark. So I decided since I have 25K miles on the clock and my spark plugs are the original plugs, that I would change them out to see if this would fix the issue and if not I would move on to the fuel pump/fuel filter. Lo and behold, changing out the spark plugs fixed the issue and my bike fires right up, no hesitation/dragging cranks or backfires from the exhaust. Runs like new now.

I tell ya, I dreaded and didn’t look forward to changing out the spark plugs because of the area where they’re located, and my big hands don’t maneuver well in that tight space. Anyways, with some patience and trial and error it was well worth it and the next time I won’t panic when approaching this task. BTW the spark plugs ran me over $80($20 each)which I wasn’t expecting, but hey I had no choice but to pony up.

Glad you solved it. My plugs had something like 48,000 miles on them before I changed them and the bike was running fine. I'm sure the plugs come due before the valve lash check but an easy time to change plugs (if you haven't already) is when you check the valve clearances.

I'm using NOCO (NLP14) Lithium Battery for the last 3 yrs. The screen reads 13.5v when I turn on my key.
Speaking of spark plugs, as I read how abusive some motorcycle owners are pertaining to the maintenance schedule, I am amazed how long the factory parts last. The one owner of a 2016 ZX14r stated putting 86,500 miles on the Bike and no valve adjustment or spark plugs.
"Just Cliff" 2008 C14 had 104,000 miles on his original Iridium spark plugs.

I just recently switched over from Shorai to a Noco NLP14 the other day. Liked the fact that it’s smaller and lighter and can be purchased for just about 50% cheaper than what I paid for my shorai. It also has 500 CCA which helps when starting during those cold days.

* Last updated by: siroht on 1/20/2026 @ 6:52 PM *

Is there a thread about this? One of you guys should make one. OK, I might be the only person who responds but at least you know there'ssomebody out there very interested.

but if you go to the smallest Shorai that meets stock specs, it's a bit over a pound and a half. Does Norco beat that?

I believe mine weighed 2.5lbs. I used the spacers making the battery the same height to fit the strap. I am considering getting 2 NOCO batts, wire them in parallel and put them in my Mustang battery box. The battery box is about 6 inches deep. The stock battery is only a 2-year warranty with 590cca. An AGM battery is $355. A lead acid from Wally-W was $109.
I always hookup my "pulse-Tech" battery charger to try to get an extra month or 2 out of it.

This is the Shorai direct replacement for the 14R. The smaller one you were using with your 14 was a smaller capacity battery, which I had purchased when I had my 2012 14R. That smaller capacity battery didn’t work out for me that well. Intermittent starting issues, just randomly losing power at traffic lights. Once it left me stranded 30 miles from home and had to call my wife to bring me tools and my backup AGM battery to get back up and running. Afterwards I contacted Shorai and they told me I was running the incorrect battery for the 14R and stated that the LFM21A6-BS12 was their recommended direct replacement battery for the second gen 14. Once I purchased it I no longer had the issues I mentioned.

The Shorai direct replacement battery weighs in a little over 3 pounds and has a 315 CCA, compared to the Noco NLP14 which weighs in at 2.5 pounds and has a 500 CCA cranking ability. Also it’s designed so that you can attached the positive/negatives connections at various ways/angles, if my memory serves me correctly there are 3 different mounting positions you can choose from based on your specific application. Did I mention it’s also much cheaper ($129.99) and since I already have Noco Genius chargers, it was a great match and purchase.

* Last updated by: siroht on 1/21/2026 @ 8:27 AM *

That seems crazy that the battery that worked fine for my Gen1 wasn't cutting the mustard for your Gen2. As long as i had the bike running, it would go to 14v and sometimes a tad higher. I'd try another one but if it just can't do it for the 14R, I'd save it for the Gen1 I want to buy to replace the one had. I'll say this, it did seem to need to turn the motor over one more time than the stock battery but it had no charging issues after the bike was running. It didn't hold a charge well after I let it run down to low voltage during storage and that got so bad after years passed, I had planned to replace it. It still went to 14V after 15 minutes of riding the bike.

Maybe it didn’t help the poor battery because I had 2 accessories hooked up, but they were all connected via a 12V switch so no draw shouldn’t have occurred when the bike was off. However, once I switched over to their recommended capacity battery the problems no longer existed even with 4+ accessories connected to it.

My first Lithium Battery came from Battery Tender. Rated at 300cca. But after 1 year it struggled like the lead-acid battery trying to start a hot engine with the electric fans running when I turned my Key. That is the difference from Gen 1-ZX14 to Gen 2-ZX14r, 2 radiator fans drawing more Amps. Kawasaki should have wired the ignition to start the engine first, then turn on the radiator fans on a hot engine. Maybe I could add a toggle switch?

* Last updated by: doubleD on 1/23/2026 @ 12:54 PM *

Ah, I see, it's an issue with hot starts.

Check your connector from the stator to the rectifier. Mine was legitimately melted from a bad connection. I even replaced the stator and the connectors looked great. 3 months later- connector melted from arcing. I decieded to solder the lines together but am yet to test it. I kept going through batteries of all kinds after a few months thinking I kept buying duds. Nope. Bad connection there. Also check your grounds to the frame at the battery and trace the wires from the rectifier to the battery.

Look into an X2 lithium battery from Batteries Plus. 400CCA. Weighs about a pound. Available at every storefront for Batteries Plus for $150. It will last if all else is in check. These battery manufacturers are pretty good. Lithium batteries usually perform poorly in the cold. It's advised that you turn your key on and let current pull from the battery to feed the lights and ECU. This slightly heats the battery up. I haven't had any heat-soaking issues with these batteries yet.