• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

550 Top Speed problems

  • Thread starter Thread starter wegs426
  • Start date Start date
W

wegs426

Guest
I've recently noticed that my bike tops out at ~75mph. I have only been riding for a few months so it took me a while to realize something is up. When I'm in 5th or 6th gear my revs are around 5.5-6k and wont go any higher. I can get to higher revs at lower speeds. At 75 I still have about 1/4 turn of the throttle left. When I give it more throttle nothing different happens. If this were a main jet issue I think I would expect it to stumble? I checked my throttle and it is opening the carbs all the way at full throttle.

more info on bike:
1980 gs550e
4-1 with straight though muffler
K&N pods
valve shims adjusted
I went up 3 main jet sizes and 1 pilot size.
 
do you have a st.3 jet kit installed?

ok i see that you don't.
your in NY and its cold i'm sure.
bump 3 more main sizes and check it out.
when you get the extra $$$ buy a st.3 jet kit and follow the instructions.
 
Have you stripped and dipped the carbs? You're running lean but may also have a fuel starvation problem, if you have an inline filter on take it off.

And 3 sizes up on the mains isn't nearly enough with pods and a 4into1. I had to go up 2 sizes on the mains with my 550 to fix the lean condition caused by the 4-1, and I was running the stock airbox and filter.
 
I had a 550l,did the same thing.Sold it long before the internet really took off,wish i kept it,i would have dipped the carbs and adjusted the valves and brought her back.only had 16k on it,my brother let it rot.Things i did not know then.
Maintenance maintenance maintenece,all i can say
 
Probably you need different main jets, but:

Have you tried winding it out?
Fourth gear until it tops out, fifth to the red line, then wide open in sixth.

550s need high RPM to make much power, especially if someone changed to taller sprockets.
Quite often sixth won't go as fast as fifth, just don't have the power to pull 6th.


On a 550 the power starts to increase at about 7,000 RPM, anything less it won't have much.

When I had tall sprockets on my 550, it would only go about 75 - 80 if you just open the throttle in 6th.

If I ran through the gears redlining each it would go about 110 - 115 mph in 5th.
Sometimes shifting to sixth it would go faster, but usually it would drop back a little.

Just didn't have enough to pull the taller gears.
 
Thanks for all the help.

There's not many riding days left up here so I'm just going to take my fuel filter off and see what that does.

Carbs have been dipped. This winter I'll get some bigger mains in there and see how fast it can go.

..or maybe I'll find a 650 top end.
 
Not trying to be funny. Fix it up without spending much, shine it up, sell it a great running base for a cafe winter project. Buy a bigger/faster bike before the spring prices come up:)
 
Not trying to be funny. Fix it up without spending much, shine it up, sell it a great running base for a cafe winter project. Buy a heavier/poorer handling gas hog bike before the spring prices come up:)

fixed it for you.
 
Straight through muffler? As in no baffle? Think I would find a baffle for it and get some restriction back into the exhaust. I wouldn't think a straight through exhaust would be all that good on the street...especially the unwanted attention it would garner.
 
Thanks for all the help.

There's not many riding days left up here so I'm just going to take my fuel filter off and see what that does.

Carbs have been dipped. This winter I'll get some bigger mains in there and see how fast it can go.

..or maybe I'll find a 650 top end.


TEST RIDE!!!:D Get it up to top speed - about where it stops accelerating.

Pull the choke/enrichener and give it extra gasoline -- What happens?

if it goes faster and gets more power go bigger on the jets
if it falls off and gets worse go smaller on the mains .
 
Back
Top