Throttle Lag /w Aftermarket Coils

[GS550ED]

I've been rebuilding my 1983 GS550ED, and just finished cleaning and rebuilding my carburetors. I purchased and installed new Accel Super Coil ignition coils, and the install went smoothly. After I got the bike fired up, however, I noticed a lag in the throttle. I put on the throttle and it seems to sputter a little and not accelerate as much as I'm used to it doing. I checked and all of the cylinders are getting spark, and I dont have any sort of vacuum leak on the intake. I should include the fact that there was a warning on the coils that said that it may cause a "lean fuel condition" because of the "hotter spark", and needed larger jets on the carbs.

Do you think it's actually the coils causing the mixture to run lean, or could something else be wrong? This may be a big "duh", but I don't know what to do in this case. Can I get larger jets for the stock Mikuni carbs? Will I need bigger, better aftermarket carbs? Do they even make aftermarket carbs for the GS550E?

 

[SqDancerLynn1]

It's with the carbs, not the ign coils

 

[salty_monk]

How far have you ridden it? Won't be coils. That quote is BS.

Could be still flushing cleaner from the carbs, could be you need to adjust pilot screw, could be you didn't set float height right...

 

[GS550ED]

How far have you ridden it? Won't be coils. That quote is BS.

Could be still flushing cleaner from the carbs, could be you need to adjust pilot screw, could be you didn't set float height right...

Those are all definite possibilities. It has been improving, and to answer your question only about 2-3 miles. When I cleaned the carbs, though, I didn't touch the pilot screw (knew I'd probably mess it up). I did however, take off the floats when I dipped the carbs and I may have screwed that up. Will my Hayne's manual describe how and to what height the floats need to be at?

 

[GS550ED]

I should also note that it gets slightly better as the bike warms up, and whenever i engage the choke it fixes it almost completely, but ends up making the bike rev way too high.

I took it on a test ride and it would sputter and drop revs if i put on too much throttle, but again, pulling the choke while riding made the problem go away and I was able to put on as much throttle as I cared to.

Hope this development makes it a little more specific.

 

[terrylee]

No expert, but sounds as though you're not getting enough gas. Is your petcock old? Try driving it on prime and see if there is a difference. terrylee

 

[JEEPRUSTY]

I should also note that it gets slightly better as the bike warms up, and whenever i engage the choke it fixes it almost completely, but ends up making the bike rev way too high.

I took it on a test ride and it would sputter and drop revs if i put on too much throttle, but again, pulling the choke while riding made the problem go away and I was able to put on as much throttle as I cared to.

Hope this development makes it a little more specific.

This bikes will need at least 2 minutes on choke before it runs well.
If it is still short of breath off idle then turn out the idle screws.

Going up one increment in mains should not hurt either. canadain bikes are jetted richer than american one thanks to the EPA and CARB.

 

[salty_monk]

Did you replace all the other O rings? There are O rings on those mixture screws you should have replaced plus that passage could well be blocked.

Sounds like it's your issue or something to do with the floats.

Your manual should give you the float height (prob 21mm to the step on the float - search for a pic here as to how to measure them).

 

[Big T]

Ditto, it's the carbs, not the coils

It appears you may not have followed the complete carb cleaning process, which includes the mixture needle being removed and new O rings all around

Go here

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

Get a factory manual and read the tutorials on carb cleaning and tuning

Also, did you have your airbox off, or install pods, while you were having trouble revving up the engine?

 

[GS550ED]

Did you replace all the other O rings? There are O rings on those mixture screws you should have replaced plus that passage could well be blocked.

Sounds like it's your issue or something to do with the floats.

Your manual should give you the float height (prob 21mm to the step on the float - search for a pic here as to how to measure them).

I couldn't find a place that sold rebuild kits (or any parts at all) for the GS550ED's carbs, so I just cleaned everything up the best I could and reinstalled it.

I think I may have gone full retard and messed with the screw that holds the needle jet/jet needle. Other than that I didn't touch any of the adjustment devices. I did however separate the two carbs. I read that they probably need to be synced now?

Is there any place that sells components to carbs for GS bikes? I'd like to try JEEPRUSTY's suggestion and upgrade the jet.

 

[GS550ED]

No expert, but sounds as though you're not getting enough gas. Is your petcock old? Try driving it on prime and see if there is a difference. terrylee

Tried that, no difference. The petcock appears newer than a lot of the other components as well. Thanks for the suggestion though.

 

[cowboyup3371]

I couldn't find a place that sold rebuild kits (or any parts at all) for the GS550ED's carbs, so I just cleaned everything up the best I could and reinstalled it.

I think I may have gone full retard and messed with the screw that holds the needle jet/jet needle. Other than that I didn't touch any of the adjustment devices. I did however separate the two carbs. I read that they probably need to be synced now?

Is there any place that sells components to carbs for GS bikes? I'd like to try JEEPRUSTY's suggestion and upgrade the jet.

Go to www.cycleorings.com and order your orings from Rob Barr who's a member here. Might want to check everything else out from your mega-welcome to see what else needs doing. You won't do yourself wrong if you get all that done.

 

[GS550ED]

Go to www.cycleorings.com and order your orings from Rob Barr who's a member here. Might want to check everything else out from your mega-welcome to see what else needs doing. You won't do yourself wrong if you get all that done.

Just ordered a set right now- great deal they have there. I went to a dealer today and got replacement main jets (went 1 size up as JEEPRUSTY suggested, got 97.5s and 100s). I think I may have screwed up and switched the main jets, which probably contributed to the problem. I also ordered new float valves and valve needles as the valve needle was scored very badly. Once I get them put in I'll give the carbs another go. I'd order new jet needles too but they seem to be discontinued...

Am I correct in assuming that the jet needle is non-adjustable? I took it apart and the little clip on it only had one position.

 

[GS550ED]

Another question. Does anyone with a similiar model year GS550E know the nomenclature/name/model of carburetors are used in the 1983 ED? My Hayne's manual neglects to mention this.

I can't find jet needles for the carbs because Bikebandit says they're discontinued...

Scratch that, wasn't looking hard enough.

So far I have ordered: new idle jets, float valves/needles, the O-ring kit, and jet needles. I've also upgraded the main jets. I hope this will do it.

 

[Suzuki_Don]

You can raise the needles if you need to by shimming. Plenty of info on the site about that. Do a search.

 

[GS550ED]

You can raise the needles if you need to by shimming. Plenty of info on the site about that. Do a search.

Just looked it up. I'm getting some washers to shim it up a little. Thanks for the suggestion!

 

[BassCliff]

Greetings and Salutations!!

Greetings and Salutations!!

Hi Mr. GS550ED,

Here's the deal. It ran in its stock form when it left the factory, right? Doesn't it make sense to put everything back stock (except for the coils), clean/fix it up, and go from there? I think so. If you start swapping jets and shimming needles right away without first getting it to a baseline, you may be chasing your tail and end up frustrated. It's all in your "mega-welcome".

Anyway, let me dump a TON if information on you and share some GS lovin'.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Rebuild Series, and the Stator Papers. All of these tasks must be addressed in order to have a safe, reliable machine. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

And whatever you do, don't do these: Top 10 Newbie Mistakes

Thank you for your indulgence,

BassCliff

 

[Roger P.]

I've been rebuilding my 1983 GS550ED, and just finished cleaning and rebuilding my carburetors. I purchased and installed new Accel Super Coil ignition coils, and the install went smoothly. After I got the bike fired up, however, I noticed a lag in the throttle. I put on the throttle and it seems to sputter a little and not accelerate as much as I'm used to it doing. I checked and all of the cylinders are getting spark, and I dont have any sort of vacuum leak on the intake. I should include the fact that there was a warning on the coils that said that it may cause a "lean fuel condition" because of the "hotter spark", and needed larger jets on the carbs.

Do you think it's actually the coils causing the mixture to run lean, or could something else be wrong? This may be a big "duh", but I don't know what to do in this case. Can I get larger jets for the stock Mikuni carbs? Will I need bigger, better aftermarket carbs? Do they even make aftermarket carbs for the GS550E?

Are you sure you are not getting voltage leaking to ground through the wires? My new Dyna coils were putting out so much voltage they were arcing to the gas tank instead of the plugs. It was almost unrideable.

 

[GS550ED]

Hi Mr. GS550ED,

Here's the deal. It ran in its stock form when it left the factory, right? Doesn't it make sense to put everything back stock (except for the coils), clean/fix it up, and go from there? I think so. If you start swapping jets and shimming needles right away without first getting it to a baseline, you may be chasing your tail and end up frustrated. It's all in your "mega-welcome".

Anyway, let me dump a TON if information on you and share some GS lovin'.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Rebuild Series, and the Stator Papers. All of these tasks must be addressed in order to have a safe, reliable machine. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

And whatever you do, don't do these: Top 10 Newbie Mistakes

Thank you for your indulgence,

BassCliff

Wow, that's quite a bit of info. I have like 5 tabs open reading all of it. Thanks a lot! And I just got my O-ring kit that I ordered last week. ANd you're right. I've been replacing almost everything with OEM Suzuki parts from BikeBandit. The only aftermarket parts I have are the ignition coils, which, don't get me wrong, run great (excellent quality boots, wires, and mounting kit too). But they have made the bike run a little leaner somehow, so I've upped the main jets by one size. I'm going to keep the needles at the normal level and try it out, if it's still lean, then I'll shim them.

In any case, I have a good bit of research to do from what you've given me. Thanks again!

 

[GS550ED]

Are you sure you are not getting voltage leaking to ground through the wires? My new Dyna coils were putting out so much voltage they were arcing to the gas tank instead of the plugs. It was almost unrideable.

That was a definite possibility in my mind so the way I mounted the coils I made it so they get a good clearance from the tank. I also put thin little adhesive rubber pads on the bottom of the tank where the coils might get close. It doesn't seem like I'm getting any arcing...just a really lean fuel problem.