2000 VT750C: no power, then power

[flivver]

So, today's saga.

Started the bike in the garage and let it run for a minute or so, until the idle sounded happy (like always).

Headed out, and got about 1.8 miles from home... Was in a stretch where I was going about 35 MPH, and noticed that the bike was losing power. I'd give it gas, and it wouldn't comply. Then, it backfired once. Got to a stoplight, had to stop, and then when I went to take off again, the bike died.

[ This immediately reminded me of my regulator/rectifier fiasco this past summer, where my R/R went bad and caused my battery not to charge. At that time, the symptoms were a loss of power (when the battery was exhausted), coupled with frequent backfires, followed by a total stall and no chance of a restart. ]

So, I pushed it off the road and let it sit for a few minutes. Fired it up again, and it started right up (i.e. the battery wasn't dead, to my surprise). However, when I put it in gear and tried to leave, it had no power and died.

I got to wondering if I'd turned the gas off, but I hadn't. It was on, like always. I've got 90 miles on the tank, and I normally get 150, so I don't/didn't think it was out of gas. For fun, I switched to the reserve tank, and tried again. Same results.

I waited a few more minutes, and then decided to punt, and find a place to stash the bike where I could pick it up later. I rolled it down the hill I was (fortunately) on, and coasted into the closest neighborhood. On a lark, I tried to fire it up again. It fired right up (i.e. battery still good), and then actually worked... Normal power, no issues. Rode it straight home at that point, and left it there.

So, now, I'm a bit leery about trusting the bike.

Does any of this ring a bell, as to possible causes? I suppose it could have been something in the gas, that worked its way through after I switched the selector to "reserve".

Some other info that may/may-not be relevant:

1. I've had the bike seem to get stuck in a gear, briefly, more often lately than ever before (i.e. I shift, but the bike stays in the current gear for a second or two and *then* moves up). I've been ascribing this to the weather having gotten colder.

2. I've noticed an odd noise that sounds a bit like a metal zipper pull clanking on the gas tank. It's not that, though, because I don't have anything like that near metal... It's also not constant. Just happens from time to time, then stops. Could it be the stator windings or something of that sort?

3. I changed out the plugs recently, for iridium plugs (see my other thread about the choke working for a few seconds, then stalling the bike). The bike's been running great with them, though, so I don't imagine it's the plugs.

[marcham]

Have you bought gas somewhere you don't normally? It sounds like water contamination to me.

[flivver]

Originally Posted by marcham

Have you bought gas somewhere you don't normally? It sounds like water contamination to me.

Nope... Pretty much hit the same gas station, every time.

To be safe, though, maybe a shot of a "take care of water in the tank" additive is in order.

[vonh]

Might be a loose ground wire or cracked circuit board when it heats up you lose power, could be a stuck float,gas filter, peacock plugged, gas tank air vent plugged. The shifting sounds like a clutch issue try an oil change use a lighter w oil like 5w40 or 0w40, if that doesn't work, you might need to replace the clutch assemble, check your shifter master cylinder you might want to change that fluid too. In a car you have a through out bearing and clutch spring if the spring weakens or the bearing binds on the shaft for some reason you can get the same sort of effect.

[Scrapdog2grand]

Check to make sure your charging system is putting out, Check your connectors at the regulator and stator. But it sounds like you are not getting fuel, check the vant hose on the bottom right side of tank for spider webs, make sure you can blow through it.

[John Hopkins]

Take one problem at a time..First the dead bike..

You had done 90 miles when it died and you normally get 150 from a tank..this is the first issue..You switched to reserve and there was no difference until a few minutes later when you rolled down a hill and tried again..

I would put this down to fuel, first when filling up on a fast pump you get a lot of air and may not have as much as you thought although the tank would look full..next..because the bike doesn't have a wide hose from the tank to the carb it takes a while for the reserve fuel to reach the carbs, so long that you can flatten the battery before starting..next..you haven't filled in your location yet so this may not apply..but in cold areas some people warm up the bike for a few minutes before riding, although the speedo doesn't register miles you still use fuel, so in cold weather you will not get 150 to a tank..

I suggest you ride the bike as normal and fill up sooner, maybe 70 miles until the warm weather, If that cures the problem why not keep filling up at 70 miles, it doesn't cost any more and it's not a bad habit to get into..

John.

[flivver]

Thanks, guys...

So, I went home last night and the bike fired right up. Rode 'er a mile to the gas station, and wound up putting two gallons in (the tank holds right at three, I believe) -- which would line up with having ridden about 90 miles, as I get 45-50 MPG most of the time. Rode 'er home, also with no issues. My next move, I think, will be to ride 'er around the block (~5 miles) a few times tonight, before dark, to see how she does.

I'm inclined to go with the fuel angle, as many of you have suggested. I'm thinking that perhaps a bit of cruft dislodged[*] and was interfering with normal fuel flow. Switching to reserve changed things just enough to get things going again.

[*] Some of you may recall my earliest posts on this bike, back from the March/April timeframe. The bike had been sitting for four years prior to me buying it. The tank was full of rust... I cleaned it out as best I could, but I wouldn't be surprised if there's some residual gunk in there that gets loose from time to time. I had one other mysterious loss-of-power episode that fixed itself, shortly after I got the bike running for the first time. I think it may have been the same kind of issue.

Thanks for the advice!

[John Hopkins]

In that case maybe you should fit a new fuel filter..The fuel filter will trap all the crud coming out of the tank, but when it gets full it will stop the flow..They only cost a few bucks..

John.

[Scrapdog2grand]

If thats an ACE, its a 3.7 gallon tank

[flivver]

Originally Posted by Scrapdog2grand

If thats an ACE, its a 3.7 gallon tank

Good to know. I've never actually run it out of gas... I've gotten to 150 miles, and have always gotten gas at that point. I guess I should just run it until it quits sometime (well, quits on my terms; not its own ), and then flip over to reserve to get me to a gas station.