What performance mods for '85 GS550ES? (power, handling, etc)

[Nerobro]

I also have the blue and white 83 gs550E. I have had the bike for about 10 years and instead of buying something new, would like to freshin' it up I like the shock upgrade and can't wait for the pics/walk thru. How bout the fork springs? easy to install?

Fine fine fine fine.. I'll post pictures. you'll kick yourself when you see how eash it is. Fork springs are really easy to. Just be sure to cut the fork spacers square.

I am also having a fuel issue now. The bike would only start and run on choke (happened all of a sudden) now it won't start (if you twist the throttle a few times, it'll fire and die qwik) I have checked all the fuel lines, gas cap and petcock, all good. The carbs are being cleaned now. Are there any other things should look for? As for parts.....I need the little fuel door that covers the petcock, any help there? Other than that, the bike is clean with only 15000 miles. Thanks in advance.

Your idle and pilot jets are plugged. The pilot jets you can extract and clean, the idle jets can only be cleaned in place. I've detailed how to clean those already in this thread. The idle/choke jets are siamesed on these carbs so there's only one per carb. (like one diaphram, and one float, and one float valve)

[emjay]

Great bike, by the way. I've been looking for one of those. I have a cruiser and also want a sport bike.

I redid my front forks myself recently with $70 Progressives and 15W oil and it went fairly well and made a big difference. I cut the PVC spacers with a mitre saw with the pipes clamped in place to get a nice square cut. I found a junk bike with 1000 miles on it that was sitting on it's side. The rear shocks were in excellent condition, so I put them on mine for now as I'm short on cash at the moment. When money's better I'm purchasing new rear shocks.

Concerning the air filter, I replaced the stock foam filter with a K&N filter. Easy job and cheap and made a noticable difference. No special adjustments needed, just oil the filter up and install it in the box.

[550ERAT]

Thx Nero....A couple of more questions. Do you reccomend one rear GSXR shock over another? Can the rear swingarm be changed to a bigger one to get a bigger tire outback? And, where can I find a new upgraded exhaust (4 into 1), I cannot find anything new anywhere. Thx again..

[Nerobro]

Great bike, by the way. I've been looking for one of those. I have a cruiser and also want a sport bike.

I redid my front forks myself recently with $70 Progressives and 15W oil and it went fairly well and made a big difference. I cut the PVC spacers with a mitre saw with the pipes clamped in place to get a nice square cut. I found a junk bike with 1000 miles on it that was sitting on it's side. The rear shocks were in excellent condition, so I put them on mine for now as I'm short on cash at the moment. When money's better I'm purchasing new rear shocks.

Concerning the air filter, I replaced the stock foam filter with a K&N filter. Easy job and cheap and made a noticable difference. No special adjustments needed, just oil the filter up and install it in the box.

Emjay, you're talking about a 77-82 GS550, not the 83-86 models. The 83-86 models have a monoshock rear. And IIRC use 15w oil stock. The progressive springs cost the same....

[Nerobro]

Thx Nero....A couple of more questions. Do you reccomend one rear GSXR shock over another? Can the rear swingarm be changed to a bigger one to get a bigger tire outback? And, where can I find a new upgraded exhaust (4 into 1), I cannot find anything new anywhere. Thx again..

The 750 and 1000 shocks tend to have more adjustablity. But that's the only reason to choose one over the other. The bike weights are simmilar so the spring weights and damping doesn't change much.

Why do you want a wider tire? Wider tires mean you need to lean more for a given corner. That's NEED not go faster for a given corner. You don't have enough horsepower to seriously endanger the stock size rubber so I wouldn't worry about it. If you're really concerned about traction, get a set of perelli sport deamons and forgetaboutit.

I can't find 4-1 exhausts either. :-/ Again, it's a don't worry about it for now thing. I"ll take a look and see what I can find.

[550ERAT]

Thanks...The wider rear tire is more for looks than anything else, but not a huge deal. I found a whole bunchof shocks on ebay so I guess I'm goin shopping.

[emjay]

Emjay, you're talking about a 77-82 GS550, not the 83-86 models. The 83-86 models have a monoshock rear. And IIRC use 15w oil stock. The progressive springs cost the same....

I was aware of that fact. I was basically just pointing out that the front forks aren't too pricey or difficult to redo, and that swapping the stock filter for a K&N is even cheaper and easier and well worth it. I only mentioned replacing my rear shocks as well to indicate most of these old bikes need new shocks.

I didn't intend to confuse anyone. I just wanted to affirm that some simple improvements can be made to improve the bikes performance.

[Jethro]

Why do you want a wider tire? Wider tires mean you need to lean more for a given corner.

Not if he gets the right rim to go with it.

[Nerobro]

no jethro. Wider tires mean you need to lean further for a given speed corner. What happens is that your contact patch moves further when you lean over. So your bike needs to lean even further to keep the CG over the contact patch.

In fact.. putting a wider tire on a narrower rim reduces this effect. ;-) Though that screws up the shape of the carcass.

[550ERAT]

When I change the rear shock from stock to the GSXR model. I know I have to remove the center stand to put it on but does it stay off? and do I re-use the mounting bolts, get new ones or use the ones from the GSXR? Also, the canister attached to the shock, what goes in it? Thanks, and no stone breaking of this is a really stupid question, thx.

[Nerobro]

When I change the rear shock from stock to the GSXR model. I know I have to remove the center stand to put it on but does it stay off?

It stays off. You'd need to make a new centerstand to continue using one.

and do I re-use the mounting bolts, get new ones or use the ones from the GSXR?

The bolts are thes same.

Also, the canister attached to the shock, what goes in it? Thanks, and no stone breaking of this is a really stupid question, thx.

The canister is full of nitrogen and shock fluid. You should never go in there. :-)

[AOD]

Do they make a single shock replacement that allows you to retain your center stand? Center stands are nice...

[Nerobro]

Yes, but those shocks are between $400 and 1200. :-) The GSXR shock is between $15 and 60. If you modify your centerstand you can keep it.

[550ERAT]

What Is The Mod To The Center Stand To Keep It?

[Nerobro]

it would require welding and creativity. :-) And it would be up to you.