• 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.

85 GS550l hits a wall and wont accelerate

  • Thread starter Thread starter Mankow
  • Start date Start date
M

Mankow

Guest
Im working with a 1985 gs550l and I ran in to some problems after cleaning my carbs. here is my old thread just on the carbs. I took them off pulled them apart and let the metal pieces soak overnight in carb cleaner, then after finding out the jets were wrong and one of the carbs had the wrong size float valve I ordered the correct size jets went from 97.5 all around to 95 on the outside and 102.5 on the inside and float valve, all mikuni parts. Then replaced all the o-rings with a set from cycle o-rings and in the process replaced all the bolts with hex head bolts. So I put everything back together, it now idles great once warmed up with the choke off its steady @ around 1k rpm and I can go lower without it stalling. But I took it for a ride and I pushed it kinda hard I think I was at about 8k rpm and suddenly I just lost power as if I had let go of the throttle, after that I could not get it to accelerate past 4.5k rpm it didnt matter where the throttle was. wide open it would pull hard till I would reach 4.5 then just nothing more. same if i slowly let it reach 4.5.

So I replaced the rubber boots and hose clamps between the carbs and the airbox, replaced the fuel line, the vacuum line to the petcock. If the bike is in neutral it will rev freely with no hesitation, and if im riding it when it starts to lose power if I pull the clutch it will instantly rev up. after replacing the boots it accelerates better reaches about 6k and after that it will accelerate but just very slowly, same deal as before though it doesn't matter what position i have the throttle. I have not pulled the plugs yet to check them I will be doing that tomorrow. and I have a new oem spec airfilter on the way.

also I have a video of the vacuum at idle and with some slight revs, nothing with a load on the engine i can post it up if it would be helpful, and I could record a video of the vacuum with a load if it will help.

and before I cleaned the carbs the bike would accelerate fine, but could not hold a low idle, I would have to keep the choke slightly on and the bike would idle just below 2k rpm or it would stall out when I would come to a stop, also at low speeds like starting off if i went to slow it would backfire and pop, which it no longer does, so I fixed one problem and picked up another.
 
Change the igniter See if you can find one and try it or get a Dyna S but you will need a mechanical advance.
Probably your problem.
 
Bummer.................
:o

one of my 1st encounters..bike had under 1k miles and no spark.
dealer wanted several hundred for a new ignitor...woooooo
1150 box plugged right in but still no spark...same plug..different wire colors...oh well.
customer said no way.."small diameter" signal generator is the problem with interchanges.
 
I'm wondering if a earlier mechanical advancer plate could be fitted so the dyna could be used.
 
has nothing to do with the advance mechanism....those will interchange.
the trigger plate that sits back into the crankcase is quite a bit smaller on the 83-86 550's.
a dyna or an earlier model trigger plate is to large in diameter to fit into the engine case.
 
So, anyone have a 83-86 gs550 ignitor that they dont want an arm and a leg for? or has anyone been successful in taking it apart and rebuilding it?

I have not yet tested my charging system but is it possible that a bad charging system could give the same problems as a bad ignitor?
 
Mankow;2135161 I have not yet tested my charging system but is it possible that a bad charging system could give the same problems as a bad ignitor?[/QUOTE said:
A faulty charging system could have excessive voltage that likely would fry the ignitor.
disconnect stator and R/R from harness and see if you get lucky.A decent battery will last maybe 1 hour without charging help.
 
Last edited:
Alright so I finally got around to checking the voltage, I hooked a voltmeter up to the battery and rode the bike around, and it barely changes no matter the engine speed. at idle its around 12.8v-13.2v and it stays the same if i rev it no load hold it at about 5k no load or any rpm with load always right around 13v. the Clymers manual says if its less than 13.5v than it could be either the R/R or that stator. also I have not tested the battery since I keep it on a maintainer whenever I am not riding, but it came with the bike when I bought it.

also I checked the voltage to the coil and it was somewhere around 11v so I did the coil relay mod and am getting full power to the coils. I should have a replacement igniter on the way soon but if that is the problem I want to make sure i dont just fry the replacement one.

As I was doing the relay mod I noticed that it looks like my R/R has been replaced, the bolt holes dont line up so it was held on with 1 bolt, there is no connector to the harness but newish looking spade connectors and this is what it looks like. doesnt look like the one on partsoutlaw. I found a replacement on ebay but does it sound like it isnt working right?

just did a no load alternator test, I didnt rev it to 5k it was only about 2k since i was just running on leftover fuel in the carbs but if I did the test right it was only putting out around 55v ac Clymers says it should be 75v AC for the tscc models.

so will a faulty electrical system cause the bike to lose power at higher rpms?

I know this doesnt really belong in carb/fuel/exhaust anymore but it made more sense to keep all the info in one place rather than two separate threads
 
Last edited:
".....so will a faulty electrical system cause the bike to lose power at higher rpms? "

Maybe, but I doubt it- disconnect the r/r and stator and take for spin.
Your charging is poor, probably connections or r/r itself, since your open circuit stator AC test seemed promising. High charging system voltages kill ignitors. Do a quick test from here and report all 6 results.

http://www.thegsresources.com/_foru...System-QUICK-TEST/page2&p=1272192#post1272192
 
So, anyone have a 83-86 gs550 ignitor that they dont want an arm and a leg for? or has anyone been successful in taking it apart and rebuilding it?

I have not yet tested my charging system but is it possible that a bad charging system could give the same problems as a bad ignitor?

Repair your own (the first sticky post in the electrical section)
http://www.thegsresources.com/_foru...19-81-GS550T-ignition-replica-for-a-few-euro-!

Or build from scratch...
http://www.thegsresources.com/_forum/showthread.php?221370-The-GS-ignitor-diy
 
I have been away so no real progress I have sourced an igniter and I have a new stator and R/R on the way just in case. Ill do a battery test tomorrow but im pretty sure the battery isnt any good. And yeah I was kinda exited to build my own igniter then realized that it wont work with my model.
 
his model has an electronic advance ignitor...no DIY for those.
Damn.
I have been away so no real progress I have sourced an igniter and I have a new stator and R/R on the way just in case. Ill do a battery test tomorrow but im pretty sure the battery isnt any good. And yeah I was kinda exited to build my own igniter then realized that it wont work with my model.
I'd look seriously at picking up a used Megajolt unit and making it work with the factory triggers, in that case.
 
The igniter/ignition uniqueness with lack of an aftermarket alternative is the reason that I consider the '83-'86 GS550 units to be off limits for restoration projects. The igniters were once plentiful on ebay, but no more.

I can see if Cycle Recycle here in town has an igniter if you'd like.
 
Thanks, I have a used igniter on the way. Yeah this is my first bike and I bought it on a whim if I had done more research before buying I would have made sure to by an earlier model, and honestly once I get it running I will probably sell it to buy a model with more support.
 
Back
Top