What's wrong with this bike?

[Poodle Head Mikey]

1994 Suzuki GS-500.  Has always started, without using the choke, and run well since I've had it - which has not been very long. <g>

My son has been riding it more than me and he recently complained of some 'thing' that it did
which seemed to involve a stumble and/or no power at mid range rpms. His descriptions seemed so arcane as to be useless to me so he eventually suggested that I ride it and 'see for myself'.

I wasn't able to do that until this past weekend.

It started easily with no choke and idled low but not for very long - maybe 40-40 seconds before
stalling.  Typically it idles to warm up and then runs off fine.

Then it would start but not stay running.  Then after a while it would only restart with the
choke.  Then it had a loping idle - varying between 900 and 3000; up and down, up and down,
up and down.  Switched the tank valve from ON to PRI and it made no difference.

It sure acts like a twin running on one cylinder.  But both head pipes almost immediately flash off a drop of oil at start up - so both cylinders are apparently getting fuel and firing it.

Nothing nasty or odd looking comes out of the carb drains. I was thinking that maybe there
was water in the gas tank.

Starts right up but has no power and won't idle  - choke or no choke.

What should I look at in terms of the above symptoms?

Any ideas?

Thanks!

[makenzie71]

Check your carburetor connections...make sure the throttles and fully socketed and that nothing is leaking.  Try spraying some carb cleaner around the boots when the bike is idling.  If no change, then it's not a vac leak.

I would also cheak the oil and make sure there are no sparklies or funny colors, and then check compression.

[The Buddha]

I suspect fuel flow as well ... maybe you have a sporadic vacuum line leak ... or similar ...
Lack of power but does it feel soppy and wet ... like its drowning ... or does it feel dry and raspy ... like its gasping ...
The first is a high float ... stuck float or other BS, the second is an air leak ... taking in air at a vacuum fitting or O ring etc ...
Cool.
Buddha.

[Poodle Head Mikey]

I finally found a socket that would fit the plugs. <g>

The left plug is somewhat wet looking, although
'normal' in color;  tan electrode with black outer
ring.  It smells like gasoline.

The right plug was not wet looking.  Normal' in
color, and smells slightly of oil.

Mean anything definitive to you all?

stephen
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[bobthebiker]

sounds to me like you need to pull your carbs, clean em, check the float height and it might be ok.   but we'll wait for Buddha to comment.

[The Buddha]

Well left carb float is going high ... right is OK ... BTW your plug pull is at idle right ... You may have a gas to vacuum cross over too ... that is a petcock issue ... so I guess start from there and work to the carbs ... petcock is easier to trouble shoot.
Cool.
Buddha.