A little advice for a newbie??

[Anonymous]

Hi fellow GSer's, I must say this is a great fourm. Thanks to all the great posts, the carb clean up pages by Joe, Frank, & Steve, the new orings from Robert Barr, I have been able to clean and rebuild my carbs with confidence.

I have a 1980 GS550L with only 6K miles which was a gift from my fatherinlaw. It has been sitting for the last 6 years. I was able to get most all of the surface rust off with the help of "Eagle Brand Neverdull". This is great stuff and is highly recommended for getting the chrome back to normal.

My bike came with 92.5 mainjets. I have purchased a new 4 into 1 Kerker header and a stock airbox replacement K&N air filter which I plan on using both of these. My question is and Maybe some of you 550 guys have been down this road already. What would be a good ballpark guess on the right mainjets to try, 95's, 97.5's, 100's 102.5's ect....???? and also should I put a small shim underneath the jet needle to raise it up a tad. I'm at about 2500 ft. above sea level. My old plugs looked kind of sooty from running it with clogged carbs, so that isn't much of a help as far as rich or lean symptoms.

I don't want to buy a dynojet kit and it would be nice to hit it right the first time but, I know that is highly unlikely. If some of you have used this combination or could point me in the right direction as far as a good starting point, it would be of much help. Sorry for the lenghty post and thanks for a great forum. 8)

[Anonymous]

unfortunatly i don't have any advice but a question:
Where did you find pipes and the K&N airbox?
I have a friend who had a gs when it was new and he swears that a 4 into 1 and the k&N airbox was THE way to go. He also said it didn't require a new jets just a mild rejetting. if your still having truoble let me know and I can try to find out more

[Anonymous]

I found the Chrome Kerker 4 into 1 from a vendor on Ebay that sold Kerker pipes. He said that the Kerker pipe for the GS550 was discontinued
but his supplier had one of them left. I got it for $300 + shipping which for new I didn't think it was to bad. I can give you his contact info if you want it. As for the K&N filter. I mean, just a stock replacement type K&N filter p/n SU 5500 which goes in place of the factory filter. I got it off of an Ebay auction for $22.01 which I thought was a good price considering most mail order places get $50 + shipping.

Yea, I know what you mean as far as mild jetting goes with this set up. K&N claims that you can get by with no jetting changes with there replacment filter and usually with just a pipe change in itself, stock jetting is maybe a little leanish but will work ok. But, with the combination of the hiflow K&N filter and Kerker pipe, I figure I'll need to at least go up a few sizes on the mainjets and maybe twist the air screws out a little farther.

I was hoping that someone with a 550 had used this setup and could tell me there results. I may just start with the stock 92.5's to begin with since I have them, then take a plug reading and go from there. Dennis Kirk sells mainjets in packs of 4 for $10. So maybe I'll only have to pull the carbs once to change mainjets if it ends up lean which it most likely will. Maybe on the second try I can get it pretty close. "Time will tell." Thanks for the reply!!

[earlfor]

Re: A little advice for a newbie??

For those same changes, Vance and Hines suggests going up two sizes from stock as a starting point. I would start with 97.5 jets. That should be about right.

Earl

[quote="MountainGS"]

My bike came with 92.5 mainjets. I have purchased a new 4 into 1 Kerker header and a stock airbox replacement K&N air filter which I plan on using both of these. My question is and Maybe some of you 550 guys have been down this road already. What would be a good ballpark guess on the right mainjets to try, 95's, 97.5's, 100's 102.5's ect....????

[KEITH KRAUSE]

Earl beat me to it. I too would try the 97.5 and test/get plug reads.
I'd leave the needle alone unless you get some lean plug reads after several miles of 60 mph cruising.
This only applies if you are keeping the air box LID on.
Some people take the lid off. It makes a big difference to the jetting.
By the way, the screws are called pilot screws. They adjust the amount of mixture, not just air or fuel. Adjusting them out increases the amount of mixture.

[Anonymous]

Thanks guys!! 97.5's it is. Like you say, this should be a good starting place. Thanks so much for the reponses. I'll let you know how it turns out and also post some pics of her after I get it back together.

I've still gota take both of the calipers off and get them freed up so they won't be dragging me down. I'll order me up some 97.5's from Dennis Kirk
and hopefully by my next off day I can get her running.