Starting the bike after it's warm - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
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post #1 of 20 (permalink) Old 07-07-2018, 08:23 PM Thread Starter
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Starting the bike after it's warm

I don't have much of a problem starting the bike when the engine is cold. Full choke, give it a little throttle, then a little throttle again with the starter, and it usually doesn't give me any trouble. I also posted last week about having adjusted the idle knob, and feeling a lot better about the mixture and the way the bike runs since then.

This afternoon I took a nice little afternoon ride. I was probably out about 20 minutes, and then I came back to my neighborhood. I was talking to a neighbor about my bike earlier today, and he was a long-time rider, so I stopped by his house to show it to him. He wasn't home, and I was concerned on my way back to the bike whether it would start up easily or not. I had a feeling that it wouldn't, and I was right.

It's one thing to have this problem in your own driveway or garage. It's another to be out on the street trying to start your bike. And thank goodness I didn't stall at a traffic light or something, and have a hard time getting the bike started again.

Anyway, I tried to crank it several times, and pretty soon felt like I was going to have to leave it parked outside his house, and come back later when the engine has cooled down. Like everybody does (I guess), I start adjusting things when it doesn't want to start. But I'm just guessing. More choke? Less choke? Should I adjust the idle knob? Heck, I'll even try the key and engine cutoff switch a couple of times, just to feel like I'm doing something.

The worst part was that it backfired again, while I was trying to start it. This is a very loud exhaust backfire (well I guess it's the exhaust. That's what it sounds like, but I can't be positive it's not a cylinder, I guess). Eventually I tried just the start button without the throttle, and it coughed to life. I quickly gave it some gas to keep it from dying, and then I checked my mirror and pulled immediately.

In second gear, it stalled out, and I tried to start it again while coasting. Eventually it came to a stop, and I tried to start it again, surviving one more backfire before getting it fired up enough to get around the corner to my house.

So it was a great ride, but I don't at all like the idea that I can't shut off my bike, or else I won't be able to get it started again. The troubleshooting starting points seem endless as this point, though, so I'm not sure what to check first.
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post #2 of 20 (permalink) Old 07-07-2018, 09:33 PM
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I've found that using full choke after a brief stop is usually what mine needs. If it doesn't fire first try, I choke it until it fires. I always leave the throttle closed.

Much of the backfire can be from lower than optimum cranking volts. Long cranking drops the voltage quite a bit.

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post #3 of 20 (permalink) Old 07-07-2018, 10:31 PM Thread Starter
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Yeah, I really do need to get an AGM battery and an on-board voltmeter. Both of these are on the "first things you oughta do" list, and I need to do them. I do have a trickle charger, which is nice. It came with the bike. But like many things, I think it's controversial, because some say it's better to take the bike through it's normal charging and expending cycles, rather than to keep it topped off all the time.

A new battery probably couldn't hurt, and some sort of on-board voltmeter (whether the installation is as fancy as I want) would help me to at least have more information when I have trouble starting it.

You never use the throttle to start, eh? I just took the advice of the previous owner, when he told me how he starts it. When I got back, I noticed the idle was a little low, so I adjusted the knob a bit more. It's supposed to rain here tomorrow, so I'll probably take another ride later in the evening. We'll see how it goes.
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post #4 of 20 (permalink) Old 07-08-2018, 01:48 AM
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Clean your RR plug and it'll quit doing that if your battery has proper voltage.
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post #5 of 20 (permalink) Old 07-08-2018, 01:53 AM Thread Starter
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I just went on that late-night ride. First I made sure the battery was fully charged with my trickle charger. I've decided that I probably need to suck it up and stop looking for the world's greatest deal on an AGM battery, and I need to just go to the store tomorrow and buy one. So I'll do that. Meantime, though, I needed to ride with the battery I have, so I wanted to make sure it was fully charged (that's usually what I do, though).

Speaking of purchasing decisions, my multimeter also broke recently, and I've been trying to decide whether to invest in a really nice one or buy a cheap one to get me by. That could tell me what my cranking voltage is, but at the moment I'm in the dark. I can also get that checked at the battery store tomorrow, on the old one.

Anyway, I tried to start it with no throttle this time, and it started right up at the house. As I said, the cold start has not given me any trouble. Full choke, that is. I went out and had a good ride, and didn't have any trouble with stalling, or near stalls, or anything.

Anyway, I wanted to stop for gas, for two reasons: First, I'm getting low on gas Second, I knew I needed to test the shut down and restart. I made a decent entrance into the gas station and got my gas. Gas stops on the bike are so short that you could _actually_ do it without shutting down. I do that with my car sometimes. I don't know if it's any more risky with a bike than with a car, but I've pretty much decided that, most of the time, in a car, shutting off the engine isn't all that important (I feel the same about shutting off a cell phone on an airplane. I figure if either of them were as dangerous as they make it sound, they would simply make it impossible to do either).

But I digress. I did shut it down, and then I tried to start it the same way I had before. Full choke, and just the starter button. Cranking, cranking, but definitely not starting. OK, now time to give is some throttle (that little starter button and throttle dance that I do, to feel like I actually have any idea what I'm doing. Essentially the same way I would start a car that doesn't want to start).

Pretty quickly, I got a backfire. I'm really trying to tune out the rest of the world and not pay much attention to what I think they might think of me (an important thing to do when riding a motorcycle, especially if you're naturally a little too in tune with what other people think of you), but I'm gonna have to do something about the backfires. They didn't start until about a week ago, and it's pretty a pretty reliable occurence when starting the bike after I've been riding it.

Fortunately, Spockster has suggested low cranking volts as a potential cause, so the battery replacement that I've now decided will happen tomorrow will hopefully solve that problem. That idea is also consistent with the idea that it just started recently.

I will update the thread after I've made that swap.
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post #6 of 20 (permalink) Old 07-08-2018, 06:39 AM
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if the battery replacement dont fix it, the pick up coil mod will

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post #7 of 20 (permalink) Old 07-08-2018, 08:54 AM
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Yes it sounds like an AGM battery would solve the problem. Your battery doesn't need to be placed on a trickle charger if you ride it often, and I'm not aware of any controversy about using one. As a matter of fact the AGM battery should be able to start up your bike even if it has sat for 4 weeks. (Provided the bikes charging system had sufficient time to charge the battery....a two minute ride up the block isn't sufficient)
I found that installing iridium plugs helps too. Backfires when starting are usually a sign of a weak battery.
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post #8 of 20 (permalink) Old 07-08-2018, 09:37 AM
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For Multimeters I have a pile of Harbor Freight cheapies, sometimes they are free if you buy something else. Work well enough for most tasks.

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post #9 of 20 (permalink) Old 07-08-2018, 06:51 PM Thread Starter
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I have two updates. The first is about multimeters. I love watching the videos of this guy called AvE, and he published this video just yesterday, in which he compared a really cheap fork meter (by Ames) from Harbor Freight with his Fluke meter (which he loves). The end result was not what you would expect. Yes, you get what you pay for, and he certainly made no claims that the Ames would last as long or be as good as the Fluke. But depending on who you are and what you need, he was reasonably impressed with the accuracy of the Ames, and certain features of it. And the price, at $59, is incredible.

So I took myself out to Harbor Freight this afternoon, and they had a ton of Ames models on the shelf, with the little tickets that you can take to the cashier, so the meters don't get stolen. My cashier looked and looked, and eventually told me they were out of that model (never mind the number of tickets they had on the shelf).

But I had a backup plan. Yesterday I searched Craigslist for Fluke meters (because why not), and there was a guy selling a new one, still in the box, for $80. That model runs about $120 and up. Yes, of course I could have bought a super cheap multimeter, but something about watching this guy's videos has steered me in the general direction of quality, and "you get what you pay for." Obviously I have more uses of a multimeter than just the motorcycle. I keep 4 cars operational for my family, and do various things around the house. So I needed a new one anyway, and getting a quality instrument for at least 30% off... I'm in.

OK, so now to the battery adventure. I went to Batteries Plus (seems like a reasonable choice). It turned out they didn't have the AGM battery that fits the VN750. But before he told me that, he did test my old battery, and told me it had a "dead cell" and needed to be replaced (that's important. We'll come back to that). So I left there, having gotten a free battery test, and knowing that I was lucky my battery was working at all. Right? We'll see.

Next step: Walmart. Mostly because I had been wanting to check their prices and availability anyway (I have not found a way to filter out online-only products on, so if I really want to know what they have in the store, I have to go to the store). This lady in the Auto department looked at my battery, I told her I wanted the AGM replacement, and she went and picked it right off the shelf. I left her my old battery (to save the core charge) in a shopping cart that was collecting them for the day, paid for it, and left.

Got home, and immediately saw the problem: It was the right size, but the positive and negative terminals were reversed.

So, back to Walmart. First, I used their battery finder online, to make sure it found the right battery for the VN750. They pointed only to a conventional battery. At this point, I was almost willing to settle for conventional, if that was all I could find, just to solve my immediate problem and get rolling again (yeah, that's a dumb way of looking at the world, but there I was anyway). There happened to be another motorcyclist at the counter this time, who also works at Walmart, and he reminded me that an AGM battery is "plug and play," while a conventional battery has to be charged before use. So he got me out of my conventional trance, and I decided to go elsewhere to find the battery.

I finally found one at AutoZone. It was $81 plus the $10 core fee, plus tax. I decided to pay the core fee, and keep the old battery, because I wanted to see the problem for myself. Now that I had spent the $80 on the multimeter, I wanted to see the cranking volts lower than they need to be. If not on the first start, then on subsequent starts.

So, once home, with the multimeter and the two batteries, I did a little testing. And I was unable to see a difference between the voltage of the two batteries. I started the bike numerous times with the old battery, and it never gave me any trouble.

So... what's up with this "dead cell" nonsense? Was that guy just taking me for a ride? He knew I didn't know any better, so he decided to sell me a battery instead of sending me on my way with my old one?

Edit: One Google search later, and I was armed with the knowledge of how to test each cell. There are six cells, and each one needs to show 2 volts. I watched a very short, very simple video that demonstrates how to test each cell. I have now done so, and of course, every cell checks out (why would they not, since the whole battery was reporting a full charge (over 13, actually). That burns me up that the guy would tell me it has a dead cell when it doesn't.

I know that putting an AGM battery into the bike is the right thing to do, long term, and I hate this backfiring problem that I've been having so much that I'm happy to do it, if it will really solve the problem. But at the moment, I'm not entirely sure I didn't buy a new battery that I don't really need quite yet.

I guess the proof will be in the pudding, so I need to ride the bike. What I really ought to do is ride with the old battery, see if I have the restarting problem, and then ride with the new battery, to see if that fixes it, but I don't really want to put myself through the restarting problem and backfiring and all that if I don't have to. So what I'll probably do is go for my ride with the new battery, and then just make sure the problem is fixed -- though I'm not completely confident it will be.

I did just run it for a couple of minutes. Is there something about an actual ride that is hard on a battery, particularly if it's near the end of its life? I would think that riding the bike would bring the battery back up to its full charge (the reported VN750 problems with the electrical system notwithstanding).

The truth is... if this problem goes away, then I don't care if I needed a new battery or not. But if the thing starts giving me trouble in the same way, then I'll be annoyed, even though I obviously have a better battery than I had before.

Last edited by readparse; 07-08-2018 at 07:10 PM.
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post #10 of 20 (permalink) Old 07-08-2018, 07:58 PM
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I'll say this one time for you. Have been on this forum for 14 years. Was on the Yahoo Group one for over 2 years. It's been the overwhelming concensus of everyone who owns or owned a Vulcan 750 that a wet cell battery is crap for the bike, regardless of how well "it tests" and that the bike absolutely works better with an AGM battery. That is why it's at the top of the list on what to do when you buy one of these bikes.
So you can experiment all you want with your two batteries, but you're never going to convince anyone here a regular wet cell battery is "fine" for this bike.
There's a reason why an AGM is recommended here. Installing one in my less than a year old 2002 completely solved any hot start problems I had. This has been echoed here for almost 2 decades.
That's why this forum is here, so you can get useful information on improvements for your bike without wasting time and money trying out stuff on your own.
If you don't want to pay attention to what we tell you, that's too bad...
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Last edited by Knifemaker; 07-08-2018 at 08:45 PM.
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