5000 RPM Engine Sputtering GS750 | acceleration hesitation | fuel starved

[Guest]

Good Afternoon,

I am having issues with a 1983 gs750e with 20,000kms. The motor starts great, idles great, idle revs great and overall sounds and drives good. However I noticed on the highway at around 4500 rpm in fifth gear (most noticable) the engine is sputtering and cutting out, if I open the throttle its accelerates fine. I was able to confirm my findings by adding more foam to the air filter. The bike runs fine but has less power. It idles high at just under or around 2000 rpm

Here are the things I have done.

1. Removed the carberators, inspected cleaned and polished. (did not inspect needle jet nor the o rings)

Where would you suggest I begin at trying to solve this issue so I can get my power back

Mathew

[tkent02]

I'd start with cleaning the carburetors completely, as described here:

http://members.dslextreme.com/users/bikecliff/

[swiftmedia]

thank you, ill do that tonight.

[azr]

Have you had the bike for long? was it running fine then started to have these issues? a bit of history would be a great help.

[swiftmedia]

I have not had the bike that long, just purchased it. the hesitation and sputter has been there since day 1, i cleaned the carbs inspect and put back together. I saw no issues with the carb it look it perfect condition. I am wondering if I plug the vacuum lines with a tee if that might fix my isssue?

[Mark1]

I just had this same kind of issue with my 1150. I took the carbs apart and cleaned them without seeing any issues. Because it was sputtering at the same RPM in every gear I started to think electrical. I took the ignition box off to take apart and lo and behold, one of the solders was cracked and the pin was moving. I cleaned off the pin and re-soldered it. After that, it was back to normal.

[swiftmedia]

I will take a look at that but am a bit skeptical, because when I add foam to the airbox it runs fine.

[Mark1]

It was more about vibration for me. As soon as I hit 5k or so, the connection was shaky. It would run perfectly up to there.