Honda 750 ACE Shadow - reserve tank petcock tubes

 

I have a Honday 750 Shadow 2003. I had a problem yesterday but have seen
this happen once before as well.

The engine runs perfectly at all times (carbs, gravity feed gas line). When
it sputters at about 200km I know it's going to reserve, which I understand
to be the shorter of two tubes feeding up into the single gas tank from an
aluminum petcock with a lever on it. I switch the lever to the reserve
position, and the bike should normally catch it's breath and start running
again - while I'm still flying down the highway.

But last night when it sputtered (and I turned on the reserve) the engine
died. I pulled over and couldn't start it for about 20 seconds. Then it
started but sputtered horribly, finally catching on so that I could ride at
about 10km/hr. It slowly gained strength as I hobbled up the side of the
freeway, until I was going about 40km/hr, then 60. After another minute or
two I was doing 80 km/hr but had no power. Then I realized I was running on
one cylinder instead of two, because I could start the hear the 2cnd
cylinder going on and off line, with associated power bursts. Then, after
another minute or two I gradually regained full speed with just an
occasional sputter. By that point I arrived at a gas station and filled up,
and all sputtering stopped regardless of the petcock position (ie: on
reserve, or not).

Because this has happened several times now it leads me to the following
ideas:

1) Because there's only about 1.25 litres left in the tank when hitting
reserver, perhaps there's not enough weight of fuel to go through the tube
to the carbs fast enough, consequently sputtering.

2) Perhaps sediment or gunk builds up in the short (ie: reserve) tube due to
lack of use, because I almost never run low on fuel. So when I finally do
run low, I get gunk going into my carbs initially.

3) Perhaps the reserve tube is plugged a little and doesn't feed gas fast
enough?

4) Perhaps there is 'old' fuel going through the reserve tube?

Can anyone suggest the most likely reason, or any other you can think of?

Thanks

Tom

 

I have the same Bike, and I experienced the same problem. I've only had the
Bike for about 2 months now, and I asked the guy if he ever ran on the
reserve, and he said he NEVER ran the reserve. The problem was a little
sediment in the line or petcock. I cleaned it out by filling up, running on
the reserve tank until it was empty, switch back to main tank, go directly
to gas station, then fill up again, then run on the reserve tank. I repeated
this a few times and it cleaned out by itself. I also added a little bit of
fuel stabilizer to assist cleaning. Try this if it happens again. If it
clears up, you will know that was the problem. Good luck, and please post
your results.
============================================

 

Since you have the same bike perhaps you could comment on the
chain/sprockets as well. I have 37,000 km on the bike and have always
maintained the chain, first with 90 weight gear oil (as recommended in the
owner's manual), and then more recently with chain wax (because I ride rain
or shine, and chain wax doesn't come off in the rain like oil does). It's in
okay shape - teeth are worn modestly but still quite good.Chain looks great.

Nevertheless I get a "sh ... sh ... sh ...sh " sound as my bike rides. Not a
seriously loud sound, but I can tell it's the chain/sprocket drive as
opposed to front disk rubbing, because if I put the front brake on the sound
still happens. So I pushed the bike up and down the driveway and at a
certain point there's a bit of resistance and I can hear and feel something
grab for a moment, always at the same position. Must be a sticky link?

What do you think?

Thanks

Tom

 

Mine is a 2004. I think it was at that year, they changed the drive
arrangement to a car-like shaft and pinion drive, doing away with chain or
sprockets. At 37,000 KM's, have the rear brakes ever been changed? That
sound and at the same place on a revolution of the wheel could indicate that
at some time, the rear brake was applied very hard, and made the brake drum
out-of-round. As the drum goes round and round, the pad might be contacting
the drum at the low spot, as the brake pad is in a fixed position, and the
drum circles around it. The clearance between the pad and drum might be
varying enough to bind up at a certain spot. It would take a dial indicator
to measure the run out. That would be the first thing I would check out. Do
you live near Edmonton, Alberta? I could check that for you.

Roger

================================================

 

Part 2

The reason I didn't address a binding chain link, was that while the
sprocket rotates at exactly the same orientation as the wheel, a seized link
would vary in position every rotation of the rear sprocket, due to the gear
ratios between front and rear sprockets. I hope this all makes sense.