1982 GS550L Project

[Demonthrall]

Alright, decided to make one thread for my bike, to get it running correctly. 1982 GS550L bought it with 32,000 miles.

ISSUES
___________
-PO drilled baffles (both big and small holes in exhaust tip)
-leaky valve gasket, half moons
-retapped valve bolt
-uneven idle, dies
-surges, pops, backfires


Work I've done so far (engine only)
__________________
-Dipped carbs
-replaced 'O' Rings, including intake boot ones
-adjusted valve shims to spec
-replaced valve and breather gasket
-installed dynojet stage III jetkit
-installed K&N Air pods

Charged the battery, primed the bowls, At this point it only starts if you are goosing the throttle, and will run for 3-5 seconds, then bog down and die. It will not idle on its own.

My guess is that the pilot jet is too lean, but the main jet is too rich? thoughts?

 

[Demonthrall]

Attached is a picture of the pods. There are two of them, with each one covering two carbs. A unique solution to the GS550L frame being in the way of traditional pod size.

 

[Danjal]

Nice solution there. I would check your plugs and clean your filter. It could cure some of yor backfiring issues. After that start fixing all the other known problems. Once you weed all those out see how she runs. It could be a clogged fuel line. Sounds like its not getting enough fuel in there. Could be float heights. Could be the chokes arent working correctly or arent sealing.

 

[Demonthrall]

Air filters are brand new. fuel line is unclogged. Petcock has been cleaned, not worried about that, since it worked fine before. 3 of the 4 plugs were wet, and one was dry but carbon fouled. I obviously cant do a proper plug chop though....

 

[mike_of_bbg]

Hmmm. My first guess was rich. You shouldn't have to open the throttle. When you're getting it to start, what exactly are you doing? Choke on? You didn't mention it, so if you're having to open the throttle and you don't have your choke on it sounds really rich.

Where did you set your idle screws?

 

[Demonthrall]

Hmmm. My first guess was rich. You shouldn't have to open the throttle. When you're getting it to start, what exactly are you doing? Choke on? You didn't mention it, so if you're having to open the throttle and you don't have your choke on it sounds really rich.

Where did you set your idle screws?

It seems to start easier with the choke on. I have adjusted mixture screws from one turn to 4 turns out, it doesnt seem to make much of a difference.

 

[Guest]

Did you take out the pilot jets and check them for debris?
Spray carb cleaner into the pilot air jet and it should blow out the pilot jet port in the float bowl area. Spray it into the main air jet and it should blow out the main jet area.
These two jets are on the filter side of the carbs. The pilot air jet is removable and the other is not.
Did you take out the idle mixture screws and blow carb cleaner through them and it should blow out into the carb throat, replace the o-ring on it and make sure the little washer was next to the spring and the o-ring on the end.
You seem to have covered your bases and I hope it's just crap in your carbs.
Is your tank free of rust?

 

[Demonthrall]

yea, i did a proper soak of jets and all. The tank has no rust.

The stock pilot jet is #40, so I order some of the 42.5 just to see what happens.

Do you guys think the main jet is too big? from 92.5 stock to 150 (dynojet)? The jet hole itself looks like a really dramatic difference

 

[Guest]

Adjust the main jet so you can achieve red line at full throttle with good color at the plugs
Then adjust the needle to lose all hesitation. Start with the clip near the bottom to start rich.
Then adjust the idle mixture screws to achieve the best idle.

 

[Demonthrall]

Adjust the main jet so you can achieve red line at full throttle with good color at the plugs
Then adjust the needle to lose all hesitation. Start with the clip near the bottom to start rich.
Then adjust the idle mixture screws to achieve the best idle.

This sounds like really good advice. I will pursue this.

My stock pilot jets are #40, and I just got #42.5 in the mail today. I will install those tonight or tommorrow hopefully and let you know what this does to the idle.

Interesting note: All 4 of my boot intake O rings had cracks in them, when I replaced them.

 

[Demonthrall]

Here's a dose of humor. I am willing to tell it, ego aside, for posterity sake.

Took apart the carbs last night:

-Installed #42.5 pilots, in place of stock #40
-Found that I had forgot to replace choke O-rings, as OEM were dried and shriveled
-Set float heights, some were off by 1-1.5mm
-Found that when I was trying to start it last time..sigh.. I had the gas going into one of the vents, rather than the fuel inlet.


So, the carbs are sitting assembled on my workbench, I will install them tonight and give it a go. I'm glad I found something stupid. Stupid is way cheaper to fix in this case.

 

[Demonthrall]

ok...

I put the carbs back on the bike, and now I cant get it to start. Not even a "putt putt" like its trying to start. When I have everything hooked back up, I tried choke in all positions, holding the throttle closed, 1/4 open, wide open, as well as turning the air screws 1, 1.5, 2, 2.5, 3, 3.5 turns out.

When I first put it back together, I put the petcock to prime for about 5 seconds, then back to "on." This used to cause the bowls to leak, but it doesnt now. The engine "putt putted" twice (carb cleaner) then refused to turn over after that.

I turned the petcock to prime for like 90 seconds, and its not leaking. This isnt normal is it? I suspect my carbs are not getting gas, but when I disconnect the fuel hose, gas comes out of the line. This, in my mind eliminates the petcock as suspect.

I'm wondering if a pilot jet going from #40 to #42.5 is too much.

The spark plugs worked before I took the carbs off, so I cant imagine they are causing this, especially since they ignited the carb cleaner at first.

Also, I am not sure where to start the needle shim. My dynojet kit came from Z1 without instructions, so I went off another kits, which said "3rd from the top". I tried this before installing the pilot jet. As it sits right now, if you were to look at the needle as it sits in the assembled carb, I have the clip in the VERY TOP position. I know this isnt right, but I am not sure where else to start.

I've never had the bike to a point where it wont even turn over a little bit. This scares me.

Please help me guys, I am getting pretty fed up.

 

[Nessism]

Sounds like the floatbowls aren't filling. I'd try dropping a couple of the screws to see if they are full of gas. Assuming they are, the bike should start unless you fouled the plugs with too much fuel. A fuel level gauge check would be a good idea at this point - to measure is to know. Another thing to check is voltage at the coils - you need 11 volts or so otherwise the coil relay mod is recommended.

Hope you get it...

 

[TheCafeKid]

What's the voltage on your battery? if it's not turning over your battery is probably dead. Secondly put the stock pilots back in. You do not need the larger pilot jets. Have you adjusted the valves? Not to be an ass but this happens so many times. Before you start sticking pods and pipes and a that on your bike you need to get it running well in stock or as close to
stock form as you can. If you don't have an airbox then obviously you can't put it back to stock but you need to start with the basics. If you're sure you've cleaned the carbs well and I mean well then set the adjustment screws to three turns out and leave them. They are not your problem. Also if your jet kit didn't come with instructions find some on line. You should have had to drill your slides which you wouldn't know without the instructions. Your battery needs to be at fully charged voltage and you need to assure you're getting spark at the plugs. If you've fouled the plugs with gas get new ones. Your valves also need to be adjusted before you even bother with adjusting your carb setting. Go through everything on basscliffs site. Do them. Failure to do them will leave you where you are now. It's that simple. There are no shortcuts

 

[Demonthrall]

Sounds like the floatbowls aren't filling. I'd try dropping a couple of the screws to see if they are full of gas. Assuming they are, the bike should start unless you fouled the plugs with too much fuel. A fuel level gauge check would be a good idea at this point - to measure is to know. Another thing to check is voltage at the coils - you need 11 volts or so otherwise the coil relay mod is recommended.

Hope you get it...

Checked #1 and #4 (so I didnt have to take carbs off bike) and there is plenty of fuel in them.

The plugs are very wet with gas.

I dont know what afuel level gauge check is? I'll speak of what I do know- The gas tank is full.

The engine turns over, there is just no ignition. Should I go buy new plugs? Will they just get wet again?

 

[Nessism]

Checked #1 and #4 (so I didnt have to take carbs off bike) and there is plenty of fuel in them.

The plugs are very wet with gas.

I dont know what afuel level gauge check is? I'll speak of what I do know- The gas tank is full.

The engine turns over, there is just no ignition. Should I go buy new plugs? Will they just get wet again?

Okay, fuel flow sounds good. Next is to check voltage at the coils and check for spark by removing the plugs, sticking them back into their sockets, laying them against the side of the engine to ground them and then cranking the engine over while looking for spark. No spark means fouled plugs. Low voltage at the coils leads to weak spark and fouled plugs.

Oh, and I agree with Josh that you might not need those fat pilots. I'm not a jetting guy though so not positive. I'd just go with the Dynojet recommendations since they are typically sound.

 

[Demonthrall]

First of all, thank you so much to both you and Ness. I answered what I can below:



What's the voltage on your battery? if it's not turning over your battery is probably dead. I technically do not know, since I dont have a working voltometer. I can tell you that the engine turns over nice and strong, and the battery was new as of last summer. I fully charged it before trying to start it.



Secondly put the stock pilots back in. You do not need the larger pilot jets. The stock ones are stripped, as I had a bit of trouble getting them out before cleaning the carbs the first time. I can certainly order #40 mikuni's if you think this is something that I really need to go ahead and do. Does one size up really cause that much difference? I figured with Pods (and much forum browsing), it would be safe to move up one step.


Have you adjusted the valves? Not to be an ass but this happens so many times. Yes, all are between .05 and .08, with the exception of Exhaust #2 which is .10.

Before you start sticking pods and pipes and a that on your bike you need to get it running well in stock or as close to
stock form as you can. If you don't have an airbox then obviously you can't put it back to stock but you need to start with the basics. I never put new pipes on, but the PO drilled out the stock ones. As far as the pods, I basically had to put them on due to the extreme deterioration of the airbox and boots. I searched craigslist and ebay for airboxes all winter and found nothing. I decided to give pods a shot, in an effort to ride this thing this summer.


If you're sure you've cleaned the carbs well and I mean well I dissassembled, dipped and replaced intake boot O-rings, fuel needle valve O-rings, fuel inlet/vent O-rings, choke O-rings. I learned a bunch from Bass Cliff and a couple of you other guys.

then set the adjustment screws to three turns out and leave them.
They are not your problem. Done

Also if your jet kit didn't come with instructions find some on line. You should have had to drill your slides which you wouldn't know without the instructions. Yes, I found a couple of other directions on the forum, as well as a Z1 rep emailed some to me. I think I drilled the slide correctly, it wasnt too difficult.

Your battery needs to be at fully charged voltage and you need to assure you're getting spark at the plugs. I dont have a working voltometer (I blame my fender tube amp ) but I did fully charge it, and the bike was turning over a few days ago before I set out to rejet. I will check when I buy a new voltometer, but from everything I know, I doubt this is the problem. It turns over strong for a long time before it dies.

If you've fouled the plugs with gas get new ones. This may be the key. I will pick some up tommorrow morning. Will the new ones get fouled again? I bought the current spark plugs mid summer last year, I'd hate to think theyre ruined already, but it would make a lot of sense.

Your valves also need to be adjusted before you even bother with adjusting your carb setting. Done

Go through everything on basscliffs site. Do them. Failure to do them will leave you where you are now. It's that simple. There are no shortcuts I agree very much so. I would have never touched the jets/airbox if the drilled pipes and deteriorating airbox wern't causing the thing to run extremely lean. I am not some young kid looking to get 90hp out of my 550 by the way, so I do know why you are asking some of these questions the way you are!

Please let me know if pictures of anything would help.


I will buy new plugs tommorrow, a voltometer, and I'll take it from there. Thanks again

 

[Demonthrall]

Okay, fuel flow sounds good. Next is to check voltage at the coils and check for spark by removing the plugs, sticking them back into their sockets, laying them against the side of the engine to ground them and then cranking the engine over while looking for spark. Is this dangerous, being that I probably have unignited gas inside the sparkplug hole? Should I take the gas tank off before doing this?

No spark means fouled plugs. Low voltage at the coils leads to weak spark and fouled plugs. Makes sense.

Oh, and I agree with Josh that you might not need those fat pilots. I'm not a jetting guy though so not positive. I'd just go with the Dynojet recommendations since they are typically sound. I had to go with a Stage 3 jetkit, since it was the only one available for my bike, from anyone. My big fear is that I spent $100 on a jet kit that is too radical for my little 550. Can I safely assume that the main jet as well as needle/needle height dont have much to do with this thing not starting?

 

[Demonthrall]

UPDATE----

I got a voltometer (is it called something else?) and measured about 9-9.5 volts at the coils. Based on this, I went to O'reilly's and picked up stuff for the Coil Relay mod, as well as 4 brand spanking new B8ES sparkplugs. I figured why not, at $2.49 a piece. Installed the mod and plugs, with little trouble, however it did take me about 2 hours, not like the 20 minutes some claim.

Well fellas, you're questions pointed me in the right direction.

She fired right up and revved to 7k before I could hit the kill switch. After some brief fiddling with the idle screw and throttle cable, I got her idling. I still have to dink around with the throttle cable though. revved her a bit, it doesnt hang nearly as much as it used to. It still does not drop immediately down after, which I desire, like some GS's on youtube. I decided to take it out for a quick spin.

The first gear pops a bit, like its still a little lean, but 2, 3 , 4th gear pull nice and hard. I assume that because I have the needle with the clip on the top groove, I could lower it down 2 and take care of the lean first gear. This is what I'll try tommorrow. I did take out plug #4 just to peek, and its a little white, which confirms my thoughts. mixture screws were about 2 out.

The last time I took it out for a spin was before a valve adjustment, stage III jet kit, k&N filters, etc... what a difference. wow

 

[Demonthrall]

So I adjusted the needle, and found that I actually had the clip in the second to top groove. I moved it down two, to the 4th from the top.

Attached is a picture explanation of my results, since I want someone to look and make sure my thinking is correct.

The idle is much smoother, but when I rev the engine or come to a stop, rpm drops from 1200 down to 800 or so and threatens to quit. Could this be because of the pilot jet being one step up from #40 to #42.5? I always heard that erroring the pilot a little bit on the rich side is somewhat safe, but Its only what I have heard.

The idle is also a little funky due to the way the throttle cable is routed, but I see BassCliff uploaded a picture of the correct routing another thread. Thanks YET again Basscliff.

Tommorrow, I figure I'll try the 3rd groove on the needle and see what that is like. After that, I really need to take care of this idle issue. I hate that the bike is unreliable in that manner.