Ducati Monster Forum

Anyone have any first hand experience with Yuasa YTZ7S batteries? Its time to replace my stock battery and I am curious if anyone has used one of these on a monster. Any issues with going to the smaller battery?

Mine lasted 4 years - without a tender -

So I just got another to replace it.......

As always, YMMV

It's the only battery I use anymore.  I've used on my personal Ducati's, my DesmoDevil, customer DesmoDevil's and friends racebikes for almost 10 years now.  Battery tender recommended if sitting for more than 30 days.  Most last 3-4years in the hot Arizona climate.  Going to use them again in my Orange Kist and upcoming customer projects as well.

Only recommendation is to upgrade your ground wires in your Ducati -- factory ones suck.  Thus all my bikes (and customers) usually pop to life immediately even if carb'd with the small battery.

Hmm, interesting.

That's the really little battery, correct?  I think that's the same one I stuck in my 900ss track bike.

Totally regretted it ever since I did it.  Even with a tender on it with a full charge, the bike just barely has enough umph to crank over and start.

Im always wondering if it will die or not during the cranking process.

But, if a ground wire upgrade would help, I'll do that and report back.  Sounds like that may be an issue.

Threw one in on Saturday. This battery is around 4 lbs. lighter than the stock unit I pulled out. I had to do a little work on the cables to make them a bit longer, as the terminals on the new battery were fliped from the stock battery. Anyhow, she starts right up. I think I am going to wire up a switch for the headlight so that I can turn it off while starting the bike, but other than that I am happy with the choice.

I think that's is what is in my carb'd M900.  I haven't regretted it once. I've got upgraded wires, and it has seemed to help.

I am considering this battery as well, but i have a few small questions about the ground-ing upgrade.

According to MotoCreations, upgrading the grounding on the bike will help this battery perform better, can someone give me a brief description of how to upgrade the grounds? More contact points?
Heavier gauge wire? I already changed the starter And solenoid wire to 6gauge,yes i know that is just the positive side.
Tear appart the entire wire harness and regound? 

thanks,
RB

From negative side of battery it goes to the frame, beef that up.

Also read to upgrade the wire from the engine (by crankcase breather) and ground it to negative terminal rather than the frame. Haven't done this yet.

thanks
more questions.....can i use the 6gauge wire i have leftover from the starter, or is that too beefy?

EDIT: the positive and negative terminals are opposite from each other...correct? what have you done to fix this?
can the battery lay on its back like the OEM?

thanks for the info folks.

The terminals are indeed opposite. The battery must lay on its back like the OEM in order to fit under the tank. I turned the battery 180 degrees keeping it laying on its back and extended the old cables by splicing in an approximate 4in. lead and a new connector end. It wasn't the prettiest job but functionally it works great.

OK so i installed the battery and upgraded the ground to the engine, since that is the larger wire from the harness...yet...the bike seems to have trouble kicking over. It seems like its dead and after a few clicks of the ignition it will start. Could this be due to the fact that my bike is injected? I figure an injected bike uses more power at start then a carbed. I can still take the battery back if i need.

thanks for the help,
RB

In my experience, the carbed bikes are the ones that are more tricky about coming to life. (lots of sweet talk involved, sometimes a little dirty talk).

If the temp has dropped considerably where you are, I find that makes starting the bike a lot harder.

i ride until the temp dips to 32f when i leave for work....this is going to be a problem?
right now it is low fifties high forties

Usually not on a fuelie, I know that starting a carbed bike in the cold is hard, with FCR's it becomes an exercise in patience

so do you have any suggestions? One thing i should mention is that the new lugs for the 6ga wire i installed (ground and positive side) didn't seem to crimp properly, so i am going to redo them on Saturday and hope that is my issue, if not it goes back to the store and i get the stocker. thanks for the help

RB

If you used crimp connectors, you might no be getting good contact with the wire inside. The best thing would be to use non-crimp ends and solder them on. I haven't had any issues with starting (fuel injected 992cc) and in fact, the bike starts after kicking over just once.

My buddy has Burndy crimp and connectors, if that doesn't work i will solder those puppies

Thanks

I have the same battery on a 900ss (ie) and have not yet upgraded the cables.

I have the same starting symptoms you do.

Cranks slow then stops.

Let off the starter and try again.

It usually will start, but I always wonder if im going to end up with a drained battery first.

you guys need some:

(http://lh3.ggpht.com/_4iYlZ1m8UEM/SbwD3FCyWiI/AAAAAAAAC2g/wp_MIQuffJE/s800/startyabastard.jpg)

(http://www.dogmall.co.uk/smile/party/party0031.gif) (http://www.dogmall.co.uk/dog-clothes/pink-dog-clothes/)

Update:
Complete 6-gauge wire upgrade(both positive and negative) crimped using Burndy ends.
Bike starts more consistently now, fires up quick....but here's the catch....
If the bike doesn't start on the first crank, i have had to press the starter again, and sometimes it seems like the compression stroke is too much for it to kick past, so pop it in gear and roll forward to move the crank.....boom, she starts.
At this point i am really on the fence as to whether this was such a hot idea to shave 3lbs. On the plus side i have upgraded the wiring sooner then getting my new harness done.
Oh, almost forgot, when she is warm starting is the same as factory battery.

As an aside, I have been putting her on the tender at night. The battery gets to float mode pretty quickly but will almost always take a bit of charge.

Sorry to hear about the continuing issues though.

Update.....
Returning the battery, going back to the stocker YT12B-BS, due to the problem that she doesn't start reliably, even after upgrading the wires as suggested.

RB

I think I may do the same.  I don't think this tiny thing has enough umph to make for reliable starting.

Been using the YTZ7S on my M800S since 11/04.  Finally changed it this year with another 7S.  My first one is still working but I was afraid it would finally die on me.  Changed out the ground and hot cabling to the starter and solenoid with 4 gauge marine cabling and installed a headlight gizmo like this fellow:

http://home.comcast.net/~mmullen38/headlightgizmo.html (http://home.comcast.net/~mmullen38/headlightgizmo.html)

Battery lives with a Yuasa battery tender. 

Failed to start me once, in a cold rain, when my power commander USB crapped out on me.  Disconnected the PC from the injectors (PITA to do in the field) and by that time everything had cooled down enough the residual charge in the battery got it started and limped home.

Sorry to hear of your problems.  Maybe it really is marginal on the bigger engines. 

i was actually unplugging my headlight when she would fail to start, because i thought every little bit would help, but no go.
thanks for everyone's help on this matter.
RB

Will the ground/positive wires be a good upgrade on a 2005 M620?

Yes, but i can't say why(not educted enough in that department) but i read lots of threads here that said the positive wire to the starter and solenoid would benefit from a larger gauge. The ground side i upgraded also.

I have had a YTZ-7S on my 2000 900IE for about three years now.  Never failed to start and even in cold weather works well.  I think a lot of the starting issues can be down to other things including earthing and from memory there were some people re-wiring their starter motors.  The little battery has 130CCA and the YB16 has 160CCA so there isn't a big difference.  The YTZ-7S is THE dollar per pound weigh mod!