1980 GS550E set up (get her running again!)

[SPT]

Hello all. Help needed with my GS550E please. It was first registered in late 1979 but seems to be a 1980 model as it has the CV carbs. Struggling to get her running right and think it's the carbs - its been an on/off project for a couple of years to get her back on the road! Before I start, I've checked the plugs (they spark and are new), points (new) and put fresh fuel in. Airbox and filter is standard and clean. It sports a very nice sounding Kirker 4 - 1 exhaust which was on when I got the bike. The bike was not a runner when I got it (given to me as a non-runner project following some 'restoration') - new plugs etc seemed to nearly get her there - would turn over, fire up sometimes on full choke but then die. I've balanced the carbs (followed the guide on a borrowed set of gauges) - she will now start pretty easily but lots of pops and bangs when ridden and stuggles to make any power like I know she should. Number 4 exhaust maniford does not seem to get as hot like the others. Tried using carb cleaning spray via the airbox when the bike was running but did not cure so took the carbs off. I must admit at this point I am out of my comfort zone mechanically but willing to learn! Carbs must have been tampered with as there was no springs on a couple of the idle mixture needles, missing o-rings but jets seemed clear. I have improvised some more springs and found some o-rings as a temp fix. Figuring I need to rebuild the carbs (no Keyster kit for this model?). I have the guide on rebuilding CV carbs printed out ready. Should I go for standard jets to start with so I have a base or should I jet up (how do you work out the size of what is in there now )? Would the Kirker exhaust be a problem which is why I was thinking I might need to up the jetting? Plugs are black after a 10 mile tip - too rich or have I got that the wrong way around? Can't seem to dial this out with the idle mixture screws. I have put a colour tune on the cool cylinder - seems OK. I've not put a compression tester on the bike but I think as the carbs balanced that must be OK - not smoking so I assume it would not be a valve causing the cool header. (have not checked valves yet) What do I do next - carb rebuild seems long overdue given the missing bits. The cool header pipe seems odd as the carbs are balanced so wondering if there is something else going on as well as the carbs- putting it into a dealer seems like admitting defeat too early and now it's made it to the front of my garage it would be a shame to push her to the back again! Thanks for any input! Simon.

[Nessism]

Yes, a proper carb cleaning and valve adjustment are in order. You will have to jet the carbs to match the exhaust, however if the stock airbox is in place the changes won't be too dramatic. Many people go straight for a Dynojet kit to save time, although they are not cheap.

[Big T]

I'll add to Ed's reply in that you need to review the 10 things in the Read ME here

http://members.dslextreme.com/users/bikecliff/images/GSR_Greeting.html

Download your manual and start wrenching

Balancing the carbs is what you do last - it cannot resolve clogged carbs or valves out of adjustment.

As to matching your carbs to the Kerker, what jet size is in there now and are the needles adjustable?

[SPT]

Thanks for the pointers. I've ordered up new O-rings for the carb and intake boots and will go shopping for the other carb bits this week. Not sure what the current jet's are. I think I will play safe by going back to new original spec ones. How can I work out what the jets are currently fitted? I've not managed to find anything out about the jetting needed for the Kirker yet. I'll start by trying to id the model and see if Kirker can help. Will take the carbs off again tomorrow to start this project!

[BassCliff]

Greetings and Salutations!!

Hi Mr. SPT,

Let me dump a TON if information on you and share some GS lovin'.

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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!

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Thank you for your indulgence,

BassCliff

[Big T]

The jets will have numbers stamped on them

Mikuni jets will also have their "box and box" logo stamped on

You'll probably want to go up a few jet sizes from stock and raise the needle

[hampshirehog]

Hi Simon,
What baffles me is that you've got a cool header on 1 cylinder but the Colortune shows that it's working ok. Even on tickover those pipes should still get blo*dy hot - and quickly.

I'm presuming you're getting your new O rings from Robert Barr (aka cycle o rings). That's probably all you'll need - the springs on those mixture screws are nothing special as they only have to stop the screw winding itself in or out (so anything similar will work).

Black plugs does suggest as you suspect that she's running rich. Worth checking those little black plugs below the mains have been put in. (part #38 on here: http://www.alpha-sports.com/suzuki_p...0GS550M/05.htm

I'd be surprised if you need to rejet to get her running (very close to) properly with that pipe and the stock airbox.

I'm only an hour away if you need any help (and I do own an exceptionally big hammer.....). If she's a runner and you're not watching the wedding feel free to bring her round on Friday.

[Suzuki_Don]

You getting married wally

How come I didn't get an invite?

I thought you'd be at THE ABBEY on Friday. haha

I would suggest that the fact that the plugs are showing rich running then you don't need to rejet. If you did 10 miles then I would think most of that would have been on the needles. They might need to be dropped a notch and see if that cleans things up.

I have a 4-1 on my 550 and have completely standard jetting for the size engine that I have and it goes like a scalded cat. Although my 4-1 is quite restrictive I think, as it has an extremely quiet exhaust note. I think it all depends on how much back pressure there is in the exhaust system. If it's loud you may need to go up a size on the main jet or two at the most.

Check the mixture at idle with the colortune and adjust as necessary. You should not need to change the pilot jets. But before all this can be done you need to have four extremely hot exhaust pipes. So go through the carbs and replace all the "O" rings and also the ones on the intake boots. My recommendation would be to bite the bullet -- purchase new intake boots with "O" rings and rebuild the carbs following the GSR carb rebuild tutorial. Stay away from Rebuild Kits on Ebay, you don't need them.

Good luck -- although you shouldn't need luch with Wally on your team. He will see you through.

P.S. Check all the jets are the correct size and that no-one has been mucking around changing them. Get the carb info off this site, if you can't find it then get back to us.

[SPT]

As soon as the o-rings arrive I will lock myself away in the garage and start work (might wait for a day my wife is out and use the kitchen table so I have easier access to some nice clean t-towels for rag and easy access to the kettle for tea). Very impressed with ordering from Robert Barr - already had an e-mail that they are about to go into the post. Pity I did not kick this off last week - they might have been here then so I crack on this friday. As it is, looks like I will be toasting the happy couple at the local pub.
Will check all the jets to see if they are standard and look again at the colourtune. That header does get hot - just not as sizzling as the others - I put it down to fuelling as when I took the spark plug out and turned it over there was a good spark, but perhaps there is something else going on. Once I am sure the carbs are as they should be, it will one thing off the list to check if that problem is still there.
Thanks again for all the help - very impressed and kicking myself for not joining a couple of years ago. I'll let you know how it goes...