the temperamental lady (83 vt750)

[MCCVIII]

it's a real treat to consistently have new reading material on this forum for the 83 750 shadow. so many threads of overhauls and rebuilds of this throaty ride, and it's a great inspiration to keep tinkering and not give up (been close at least once!) ive sought some advice from some other threads, but figured my bike ought to have a home base on this forum that i can come back to.



today was a great day for her, as she finally kicked to life and played nicely all day. since early-mid october (or so), she's been sitting in the garage, not wanting to start up. a super busy schedule and a non-heated open-air work area kept me from giving her much attention until recently. too cold. but in the last week or two, i've been trying to get her started up. it's been unseasonably warm. i must have gone through at least three full battery charges... full charged battery, crank crank crank click.... back onto the charger to repeat again tomorrow or the next day. so today when it was (70 degrees or so), she finally came to life and let me ride her up around the neighborhood for a while. no issues at all. took throttle like a champ. confused as to why the weather being warmer allowed me to start her up, and what issue that might be diagnostic of...

backstory a little bit: in mid october on the way to work, she died while riding, but through some maneuvering later that night, i got her back home where she stayed until today. she kinda went out at on the road, then let me start her back up.... rode for a bit... died again...pushed her to the gas station, then later that night, was able to shakily ride her home. never really knew why she messed up in the first place. when she was dying, it felt like she was just out of gas, but once i filled up, she still wouldnt start. and then once she was home, she still wouldnt start. until today.

so my main inquiry is... why would the temperature (seemingly) be so influential on the bike starting up? it's 59 degrees at 1am right now, and she just started right up on the first try. i've been trying every 2 hours or so since this afternoon. no issues. any ideas? i'm just glad that it seems like a manageable problem.

[MCCVIII]

also my roommate and fellow motorcycle amateur tinkerer suggested that maybe my October breakdown was caused by a grounding issue, and not being able to get spark temporarily. i was riding during the day, and can't confirm wether lights/electrics were going in and out while it was dying/not-dying.

the wiring on the bike looks definitely second-hand, complete with at least a spool full of various electrical tapes. i'm not an electrician (yet), and don't have a multimeter (yet), but i soon hope to make some tests on the electrical system to make sure the battery is getting proper voltage while the bike is at 3000 rpm and all that jazz.

might any of these symptoms imply electrical issues?

i want to give the bike a proper testing tomorrow, but if i stray too far from home base and some wiring shorts/grounds the bike out on me, i'd be SoL for sure. not interested in that for real.

[MCCVIII]

alright, here's a video (1 1/2 mins) of me draining the battery in an attempt to get it going. this was last friday i think. this was the first time i was seeing smoke come from the exhaust. give it a check-out if you want to hear/see it in near-action:

BIKE TRYIN TO START.... ALMOST
^^video link

[ZackDaniels]

Dang man... I never had such a time with this bike. The starter sounds a little sick and a bit more grindy than usual. Mine is already all tarped up and set aside for the winter or I'd take a video to compare... I wonder if the starter motor itself is giving you some trouble?

That and/or maybe the choke isn't enrichening like it should, but I don't have much for that theory other than more choke is needed for cold weather and that would explain a direct correspondence to the weather.

[MCCVIII]

tonight it regressed back to it's cold-weather state. a cold front moved in today and tonight the temperature is down at 42 degrees or so. it felt the same on a test ride today at like 2pm as it did yesterday, but when i just got home now @ 11pm, she's back to her old self.

it started up after 2 or three tries, and ran with the choke on. it wouldnt start up if i tried to start it while rolling on the throttle. it maintained a slow idle for a while, but would die if i tried to give it any throttle. eventually it stopped starting back up, and i came back inside. will post a short video tomorrow of the sound of it as it stopped running..

[SkullCrusher]

Choke on. Start bike. Let run. Idle will rise. Bike will warm up. Blip throttle, if it doesn't stumble, take off choke.

Patience grasshopper.

[mattyo]

Originally Posted by SkullCrusher

Patience grasshopper

So there's a method that a few of us old 83 750 owners use to get started on cold days. My method has evolved a little bit but is basically the same. The general idea is this:

Either with enrichment off or just slightly engaged, push the starter button. Generally my bike will pop over almost right away. But if I let go of the stater at that point, the bike will die. SO.... once the bike pops over, keep the starter button down and crank up the enrichment while keeping the starter engaged. Once you have full enrichment, release the starter, and the bike should now keep running on it's own. Let the bike warm up, rpms should gradually get to around 3000. Dial the enrichment down and take a ride on that stallion!

[MCCVIII]

righteous. im going to give it a shot now.

[MCCVIII]

no avail. cranked till the battery died, its back inside on the charger. it didnt even turn over once. just the cranking that happens at the end of this video:

Video - TinyPic - Free Image Hosting, Photo Sharing & Video Hosting

little video of it running last night, and then it not popping back on after that. it was running for 2-3 minutes before i turned the choke off and it died.

after i say "with the choke on..." and try to start it, the engine gives a little wheezing sound. it happens every once in a while in this sort of situation. dont like the sound.

[MCCVIII]

not stressing on it too hard, in the grand scheme, because if it works in warm weather, that's the time that's best for riding anyways! i would like to get it to a point where it's as reasonably happy as it can be.

would replacing/working on the air box be something that might influence this?