GS500 Problem

[cyberdork]

Starting tomorrow around 5 I am a born again GS owner. I'm picking up a 96 GS500 with under 3000 miles for 500 bucks! Thank you boss! The reason why she's selling it cheap is because when you lay on the throttle it takes a good 2-3 seconds for the engine to final rev up (not slow acceleration, just extreme delay). She took it to a local mechanic and he tried some things such as cleaning the carbs and replacing fuel lines (I'll get the complete list tomorrow). Does anyone have any suggestions? She said the valve clearances haven't been checked that she knows of. Could this be a possibility? I'm lost on what the delay could be. Isn't there another GS forum for new GS such as this one? Thanks for the help.

 

[Steve]

With the CV-style carbs on the bike, the throttle response won't be quite instantaneous, but it should definitely not take that long.

At 3,000 miles, the valves are due for inspection, but I don't suspect them as the problem. I would look very hard at carb settings, especially the idle mixture adjustment screw (are they still sealed like they were in the '80s?) and the needle height. This is all assuming that the carb float levels are correct.

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[cyberdork]

Could this be something I'm easily overlooking such as a bad ground?

 

[Steve]

Well, yeah, it could be a bad ground. :-k

A bad ground in the coils or in the ignitor or in the main power circuit could interrupt power momentarily, causing slow acelleration,
but I really don't think your problem is electrical, it's fuel-related.

Clean your carbs and set them correctly.

Also, make sure that a family of mice has not set up housekeeping in the airbox.

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[cyberdork]

I previously owned a GS700 and tried to mess with the carbs, I'm deffinately not getting into that mess again. I'm just thinking of ideas I can suggest to a mechanic.

 

[argonsagas]

How old is the gas that is in the tank?

Gasoline has a limited shelf life and will go "off" after a few months and make the carb components sticky, or block passages. It still burns, but will cause the conditions you describe.

The simplest way to deal with is really simple: drain all of the old gas, buy fresh gas and add half a bottle of fuel injector cleaner to the tank when you fill it. Use almost all the treated gas before refilling again, then add half the remaining cleaner to each of the next two fill-ups. With luck, that will be all you need to do.

Note FI cleaner tends to be better than carb cleaner, as it seems less likely to damage seals.

 

[Buffalo Bill]

Engine needs more examination?

Engine needs more examination?

Engine with only 3000 miles revs up slow?
Somebody along the line fouled up the maintenance, oil never changed, engine trashed, abused. Bike left to dry out for a few years. Carbs fouled and not cleaned well.
Do a full compression check in all cylinders, may reveal scuffed pistons and or bent valves.
Carb pistons may be sticking, mechanic must do the ?clunk test? on those. Who knows if he did a quality job on the cleaning.
How do the plugs look?
What does the engine sound like when it's running, can you tell if one cylinder is bad?
Bill

 

[81ZUKI75]

GS500 Forum

GS500 Forum

Here's a group that may can give specific help on these newer twins...

http://gstwin.com/

 

[Nessism]

First thing I'd do is clean the carbs. If you can't clean the carbs on a twin motorcycle, sell it and get a car.

 

[Steve]

Engine with only 3000 miles revs up slow?

Sure, why not? :-k

Look at the numbers:
3000 miles in about 13 years.
At an estimated 50 mpg, that's only 60 gallons.
At about a 4 gallon tank, that's only 15 fill-ups.
15 fill-ups in 13 years.

That's roughly one tank of gas per year. Why WOULDN'T it rev slow?

The best way to keep things running as they should is to keep fresh gas in it.
Drain it regularly by running it through all the assorted circuits in the carbs, then refill the tank.
Yes, I'm talking about riding it to keep it in shape.

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[argonsagas]

First thing I'd do is clean the carbs. If you can't clean the carbs on a twin motorcycle, sell it and get a car.

That is not entirely fair, as the first time is always the first time....and no one knows about it until AFTER that.

Anyway personal experience has shown the liquid injector cleaner in the gas will do most, if not all, of the job.

 

[fenderfreek]

Sure, why not? :-k

Look at the numbers:
3000 miles in about 13 years.
At an estimated 50 mpg, that's only 60 gallons.
At about a 4 gallon tank, that's only 15 fill-ups.
15 fill-ups in 13 years.

That's roughly one tank of gas per year. Why WOULDN'T it rev slow?

The best way to keep things running as they should is to keep fresh gas in it.
Drain it regularly by running it through all the assorted circuits in the carbs, then refill the tank.
Yes, I'm talking about riding it to keep it in shape.

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I can't imagine using one tank a year...I use a tank a week, at least. Why would you spend that kind of money on something to use it a handful of times in 13 years?

 

[cyberdork]

I was thinking a high concentration of seafoam and gas. The carb guru on gstwins suggested that the slides are opening too fast or too slow.

 

[Steve]

I can second the idea of a high concentration of Seafoam, but do it in a manner that might work.
Add a whole can of Seafoam to the tank, go to the gas station and top it off with gas.
RIDE THE BIKE until you put it on reserve. Refill the tank, ride it home and park it.

If it's not better by doing this, you can always try it a second time.
If that does not do it, you will have to pull the carbs to see what's going on.

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[Steve]

I can't imagine using one tank a year...I use a tank a week, at least.

I just looked in my log book.

I have put gas in my Wing 102 times in the last 4 months and 4 days.

Granted, it has not been a full tank every time, but it has been enough to cover 14,152 miles, so far. :dancing:

edit: it's now 9 hours later, make that 104 times and 14,350 miles.

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