How SHOULD my choke behave? - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
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post #1 of 26 (permalink) Old 02-28-2016, 04:26 PM Thread Starter
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Question How SHOULD my choke behave?

I'm a very new rider, so I'm not exactly sure what behavior to expect from the choke (fuel enricher on the vn, I hear), but I feel like my bike isn't working as it should. I'm hopeful the experienced around here can either allay my concerns, or point me towards some adjustments.

When I start the bike, I pull the choke lever all the way down and push the starter button. If the bike is dead cold it sometimes takes three cycles of holding the starter button for around 5 seconds each time (trying not to burn out the starter) for the engine to fire.

Once the engine is running, it idles for a few seconds at around 2k rpm, then jumps precipitously to 5k+. It feels like it would slowly climb from there, but I try to wrestle it down to around 3 by adjusting the choke lever. The choke on my bike is VERY temperamental, and the tiniest adjustment will send the rpms from below 1k back to 5k. With some luck, I'll get the choke to the hair's width position where the bike will idle nicely.

Usually this will run fine until the bike is warmed up and I can close the choke, but sometimes I'll need to make adjustments in the first 10 minutes of riding (plenty of stoplights at start of ride) to stabilize the idle. This can lead to the engine dying or revving madly while waiting for the light.

I'm guessing this isn't normal, but having nothing to compare against, I can't be sure. Could this just be a poorly lubed choke cable?

Got the bike in October, rode off and on through December. Added seafoam to the tank while it sat for Jan/Feb, and I am currently running that stabilized mix when I ride. The choke behavior has been consistent throughout.

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post #2 of 26 (permalink) Old 02-28-2016, 05:59 PM
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thats pretty much how my choke behaves, with the exception of the dead cold start time. I usually get it to start within 5 secs of cranking. you may need to clean the carbs, it might take care of that.

otherwise, it behaves just like mine. I usually have my choke fully off by the time I get 1/4 mile down road. the idle may be a little slow (a bit under 1k usually), but it idles well. BTW, I dont sit and warm my bike up much at all, unless its reallllllly cold for my area (I live in SW florida, so cold here is below 40)

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post #3 of 26 (permalink) Old 02-28-2016, 06:48 PM
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Quote:
Originally Posted by Thorn View Post
I'm a very new rider, so I'm not exactly sure what behavior to expect from the choke (fuel enricher on the vn, I hear), but I feel like my bike isn't working as it should. I'm hopeful the experienced around here can either allay my concerns, or point me towards some adjustments.

When I start the bike, I pull the choke lever all the way down and push the starter button. If the bike is dead cold it sometimes takes three cycles of holding the starter button for around 5 seconds each time (trying not to burn out the starter) for the engine to fire.

Once the engine is running, it idles for a few seconds at around 2k rpm, then jumps precipitously to 5k+. It feels like it would slowly climb from there, but I try to wrestle it down to around 3 by adjusting the choke lever. The choke on my bike is VERY temperamental, and the tiniest adjustment will send the rpms from below 1k back to 5k. With some luck, I'll get the choke to the hair's width position where the bike will idle nicely.

Usually this will run fine until the bike is warmed up and I can close the choke, but sometimes I'll need to make adjustments in the first 10 minutes of riding (plenty of stoplights at start of ride) to stabilize the idle. This can lead to the engine dying or revving madly while waiting for the light.

I'm guessing this isn't normal, but having nothing to compare against, I can't be sure. Could this just be a poorly lubed choke cable?

Got the bike in October, rode off and on through December. Added seafoam to the tank while it sat for Jan/Feb, and I am currently running that stabilized mix when I ride. The choke behavior has been consistent throughout.
I would start using Seafoam with every fuel fill up till you start to notice an improvement. At that point I would then cut back to once every other fill up and possibly stretch that out to every third or fourth time depending on how often you use the bike. Your particular situation may not be what the book states should be happening but it very similar to a large number of others here. The Seafoam can correct a lot of problems and just may get things to where you feel they should be.

and always remember, "Ride until you rot!"
**Really not sure if the Big "C" is back right now
but having to face the fact that this is a lifetime routine
going forward. Five operations done and it still continues.

Tom
Vulcan 2000
New ride: 2009 Victory Vision Arlen Ness Signature Series
4507 miles
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post #4 of 26 (permalink) Old 02-28-2016, 06:53 PM
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Quote:
Originally Posted by Thorn View Post
I'm a very new rider, so I'm not exactly sure what behavior to expect from the choke (fuel enricher on the vn, I hear), but I feel like my bike isn't working as it should. I'm hopeful the experienced around here can either allay my concerns, or point me towards some adjustments.

When I start the bike, I pull the choke lever all the way down and push the starter button. If the bike is dead cold it sometimes takes three cycles of holding the starter button for around 5 seconds each time (trying not to burn out the starter) for the engine to fire.

Once the engine is running, it idles for a few seconds at around 2k rpm, then jumps precipitously to 5k+. It feels like it would slowly climb from there, but I try to wrestle it down to around 3 by adjusting the choke lever. The choke on my bike is VERY temperamental, and the tiniest adjustment will send the rpms from below 1k back to 5k. With some luck, I'll get the choke to the hair's width position where the bike will idle nicely.

Usually this will run fine until the bike is warmed up and I can close the choke, but sometimes I'll need to make adjustments in the first 10 minutes of riding (plenty of stoplights at start of ride) to stabilize the idle. This can lead to the engine dying or revving madly while waiting for the light.

I'm guessing this isn't normal, but having nothing to compare against, I can't be sure. Could this just be a poorly lubed choke cable?

Got the bike in October, rode off and on through December. Added seafoam to the tank while it sat for Jan/Feb, and I am currently running that stabilized mix when I ride. The choke behavior has been consistent throughout.
I start mine with the throttle only because using the choke causes it to act like yours does. There are two little steps i do that you might consider. 1) Prime the carbs 2) start with the bike upright between your legs. After it's started, i turn the choke on full to sustain the idle. I back it down with little nudges to that "little area" between idling and humming fast. After it's humming fast again at that spot, i nudge it again. While all of that is going on, i am typically back out of my spot anyway. I have found it much faster to let her warm up first than taking her out in gear. Typically it's long enough to back out of my spot, finish my smoke, and put on my helmet. Only a few minutes.

Check your battery. Mine typically cranks up with only a twist or two on a cold dead overnight start. But i also keep my battery charged with a trickle charger overnight and it's a new AGM battery with the 220 cranking amps. The bike *does* charge the battery ( i've measured it several times over the past few weeks ) but it NEVER charges the battery up to its full potential. Regardless of how many times i need to stop/restart going about town, i.e. even only one trip to the store and back, it will always come back with that battery being LESS than 80% full charge.

Priming the carbs is done by turning the pitcock lever towards the rear of the bike and then turning it back to the vertical down pointing position. It doesnt take anymore than that. Just turn it to the rear, then turn it back down again. Very simple and it makes sure there is something to burn without flooding when you first hit the starter.

Unsure about why, ( yet ), but if i try and start my bike while on the kickstand, it acts differently and especially with the choke. So, i use Knifemaker's excellent logic: "don't do that".

After she's warmed up, out in some parking lot or wherever, she will just start up on the first crank. I only ever use the choke on a cold start and that goes for priming too.

Hope this helps

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post #5 of 26 (permalink) Old 02-28-2016, 09:09 PM
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Small note here. Later models lack a "prime" position on the petcock. It's just run/off/reserve...

I noticed NO difference in starting between having the bike leaning over on the sidestand or up straight on the center stand.

For cold starts I always used the choke, and yes, you need to slowly nudge it down as RPMs rise to keep the motor running in the 2500-3000 range while warming it up. Yes, you kinda need to keep blipping the throttle for a few miles until the motor reaches a good running temp.

Use of periodic treatments of Seafoam, NKG iridium plugs, and fresh REGULR gasoline helps.

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post #6 of 26 (permalink) Old 02-28-2016, 09:22 PM
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Quote:
Originally Posted by Knifemaker View Post
Small note here. Later models lack a "prime" position on the petcock. It's just run/off/reserve...

I noticed NO difference in starting between having the bike leaning over on the sidestand or up straight on the center stand.
Mine is an '87 and California I am still wondering "why" about the leaning. It's one of those "mysteries" that i am saving for after i rewire the harness. By then, i'll have figured out a way/place to store my gas-tank overnight without blowing anything up. Either that, or i will suddenly disappear from the forums.

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post #7 of 26 (permalink) Old 02-29-2016, 02:48 AM Thread Starter
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Many thanks to all who replied. Its good to know this isn't a freak occurrence.

I've been interested in rebuilding the carbs, even though I don't REALLY think they need it, I need to see the guts of something before I feel like I own it. Its possible there's a constriction where the fuel enricher joins the party. For now I'll keep adding some seafoam at fillup and see what happens.

I've bought a battery tender, but haven't hooked it up yet since this winter has allowed semi-frequent riding. Interesting that the stator never really brings the battery back up to full charge. RoadHopper, have you added some extensions to your battery cable for easy hookup? Seems like removing the seat after every ride would be a pain. If I had to do that every day I might ditch the seat alltogether and just sit on the battery to save time.

My petcock only has no prime position, so that's not an option (I'm not going to add a suction bulb to the side of my bike in order to get a vacuum before each startup).

I have also noticed a remarkable difference in how the bike starts when fully upright vs on the kickstand. Even fully choked, the engine seems sluggish right after it turns over, but upright it's immediately pulling on the reigns.
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post #8 of 26 (permalink) Old 02-29-2016, 03:22 AM
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Two reasons.number one.no living creature likes to be choked. Number two,no mmotorcycle is meant to be ridden with it's kickstands down

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post #9 of 26 (permalink) Old 02-29-2016, 11:03 AM
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Quote:
Originally Posted by Thorn View Post
Many thanks to all who replied. Its good to know this isn't a freak occurrence.

I've been interested in rebuilding the carbs, even though I don't REALLY think they need it, I need to see the guts of something before I feel like I own it. Its possible there's a constriction where the fuel enricher joins the party. For now I'll keep adding some seafoam at fillup and see what happens.

I've bought a battery tender, but haven't hooked it up yet since this winter has allowed semi-frequent riding. Interesting that the stator never really brings the battery back up to full charge. RoadHopper, have you added some extensions to your battery cable for easy hookup? Seems like removing the seat after every ride would be a pain. If I had to do that every day I might ditch the seat alltogether and just sit on the battery to save time.

My petcock only has no prime position, so that's not an option (I'm not going to add a suction bulb to the side of my bike in order to get a vacuum before each startup).

I have also noticed a remarkable difference in how the bike starts when fully upright vs on the kickstand. Even fully choked, the engine seems sluggish right after it turns over, but upright it's immediately pulling on the reigns.
The trickle charge i got is a "Shumacher Battery Extender". Cost about $40 bucks at AutoZone presently. So far, have to say they did a great job on the "kit". It was designed extremely well for the job it's supposed to do. Has a 20 foot A/C cord attached on one end, on the other is about 4 foot on the D/C side. The D/C side terminates with a molded double bullet connector. The kit has two other cords that attach to that end. One is alligator clamps, and one has metal rings that screw underneath the battery terminals. I put those in and ran that cable under the fender frame, then up again along the side and its end fits just perfect sort of poking out. So i just plug it in now when i want without any seat hassles. Used a couple of cable-ties to fix it in place.

The yellow lamp on the unit lights up if the unit is charging and will eventually flash green when the battery is charged 80% or more. It finally changes to solid green when the battery is at capacity. As you can see in the photo, the lamp is yellow so the battery is less than 80% charged. I just plugged it in this morning for the photos, and it was charged yesterday. I took her out yesterday for about 10 miles of inner city riding with 2 places i went in so, she only started up 3 times on the previous full charge.
Shumacher has been in the battery charging business for quite a long time. For as little as $40 bucks will buy theses days, and the cost of a battery being around $80, this is a no-brainer.

The difference between the first and second batteries i got was elusive. The first one seemed "okay" so i was off trying to debunk whatever electrical "short" in the bike that was happening thinking the whole time that the original battery ( which was junk ) problem had been solved. A friend of mine with a bench-top charger that had meters on it showed me how the first would accept current but mainly pass it right on through the battery. He pulled an old practically dead battery out of his "pile" and compared it with the new one. The difference in the 2nd New battery is night and day. Sure, they both crank, but the 2nd battery cranks, i get fire, and the 2nd battery is charging. I also had to replace the R/R to get the bike to charge on its own. That was another "yeah i appear to be working, but guess what" problem. I took advantage of that replacement to relocate the R/R. I also know that her stator is "weak". She's thirty years old now and it's the original stator. We measured the voltage on the alternator output. Across the battery now i get about 13.8 when she's parked and revving. And when she's at idle she is at about 13.3 ( another friend has good meters ) But being at idle and having a fan on the load and all of the lamps working, etc. etc. and turning the starter motor are way different situations... get the picture? So at this point in time, it's not worth the labor to replace that stator when i can just plug her in occasionally which i should be doing anyways.

About the leaning... yeah, easy problem to solve for the time being, just put her between the legs instead of on the kickstand. It is supposedly indicative of some sort of problem. What problem, per se, i am still digging around to find out. On the other hand, it might be the reason they changed the pitcock. But even THAT i am unsure about. People here say it has OFF/RUN/RESERVE. I don't know what positions those three are supposed to be. I DO know that mine has three spots too, when running it in the rear-pointing horizontal position it was having problems. The bike was originally set in that position when i got it. An aircraft mechanic friend of mine filled me in on it and how to prime ( same guy with the meters for the battery ). I've been doing it "his" way ever since, and combined with keeping her upright and a fully charged battery for cold starts, i've been doing just great ( all things considered ).

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Last edited by RoadHopper; 02-29-2016 at 11:06 AM.
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post #10 of 26 (permalink) Old 02-29-2016, 01:40 PM Thread Starter
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So I broke open my charger's box and I also have a quick-connect system with permanent eye connectors. Thank goodness. The only chargers I've owned in the past were clip-on only.

As for the fuel lever, for me its:
rear = off
down = on
forward = reserve
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