Lack of power and bike dies

[joe91]

Hello guys,

When I first bought the bike it ran good at low rpm. It would start to hesitate around 4k-5k rpm and would max out at ~70mph. When I take the rubber plugs off the spark plugs (one at a time), two of them make a little difference in the engine performance (center-right; far right) while the last one made almost no difference (center-left). Only the far left rubber plug would stop the engine when taken off the spark plug (other three are connected).

I cleaned the carbs and the bike seemed to run a little better, but the problem is still here. Bike is still hesitant around 4k-5k rpm. The bike also maxes out at around 6k rpm.

I think the battery is another problem. The battery is pretty much done for. I can charge it and the electric starter will work once but that's it. Other I have to kickstart the motorcycle, which doesn't always work when the battery is dead.

Just took the bike for a test-ride just now. It ran poorly. I think it's electrical. Turning on the headlight would almost shut off the bike. Turning on highbeam does stop the bike. Even the turn signal seems to almost shut off the bike. I couldn't take the bike past 5k rpm. This happened once before, but if I charge the bike and use kickstart only (electric start drains the battery), it'll run with the electrical on (highbeam headlight; turn signal).

Came back home and charged the battery for an hour. Bike starts easily but dies in a few minutes if left idling with headlight (highbeam) on.

Any ideas on where to start?

Thank you

[tom203]

You likely have many different problems- head to link below to get started
( get to first post)

http://www.thegsresources.com/_forum/showthread.php?t=171846

What bike is it??????

[nikosg]

new battery?

[Seana23]

new battery?

I agree...
Your not running a wee 2stroke that will happily run without a battery...
You got a proper bike now, which needs a proper battery AND proper new sparkplugs..

Not too expensive to get so....... Go get em.
And then get back to us...

Good luck.
Xxx

[joe91]

You likely have many different problems- head to link below to get started
( get to first post)

http://www.thegsresources.com/_forum/showthread.php?t=171846

What bike is it??????

Thanks I'll start down that list. Sorry noob mistake, it's a 1979 GS550

[sammy123]

Thanks I'll start down that list. Sorry noob mistake, it's a 1979 GS550

Getting a new battery in there is a good idea. I learned the hard way while testing my bike with a low battery and had to walk my bike home about a mile, partially up hill in 90 degree weather with a helmet and leather jacket. I thought I was going to die.

[joe91]

Getting a new battery in there is a good idea. I learned the hard way while testing my bike with a low battery and had to walk my bike home about a mile, partially up hill in 90 degree weather with a helmet and leather jacket. I thought I was going to die.

Oh man I hope you didn't feel heat exhaustion or heat stroke creeping up

Thanks for the help so far.. I'll put in a new battery and plugs within the week and give you guys an update!

[Toasty]

I would check to make sure you are getting spark on all four cylinders. Disconnect the plug wires and pull each plug one at a time and attach their corresponding wires, place against the head and crank over. Then I would check the carb boots, if they're hard or cracked they need to be replaced along with the o-rings in the carbs (from cycleorings ). Then dip the carbs in carb dip for at least 24 hours, bench sync and vacuum sync.

Also check the timing and the voltage at the coils.

[joe91]

I would check to make sure you are getting spark on all four cylinders. Disconnect the plug wires and pull each plug one at a time and attach their corresponding wires, place against the head and crank over. Then I would check the carb boots, if they're hard or cracked they need to be replaced along with the o-rings in the carbs (from cycleorings ). Then dip the carbs in carb dip for at least 24 hours, bench sync and vacuum sync.

Also check the timing and the voltage at the coils.

One at a time, I took out each spark plug and ran the test.. they all sparked (was that what you were asking?) as I also noticed these changes..

"When I take the rubber plugs off the spark plugs (one at a time), two of them make a little difference in the engine performance (center-right; far right) while the last one made almost no difference (center-left). Only the far left rubber plug would stop the engine when taken off the spark plug (other three are connected). "

Checking the timing and coils tonight. thank you sir!

[Big T]

Take all 4 out at the same time and see what happens

What color is the spark?

Do you have points?