Questions regarding upgrading a 79 GS550

[byrdman76]

I am about to begin upgrading some of the components on my 79 GS550. I am going to install a 4 into 1 exhaust, pod filters, and a dyna s ignition (the bike currently has a KOK setup). I will also be tearing the carbs completely apart, dipping them in berrymans and installing necessary parts.

couple of questions:

The emgo brand filters on ebay are at a really good price. Is the price of the K&Ns justified or have other members installed the emgos with success? If fitment is an issue (which i have read somewhat is) does anyone have any pictures on how severe the emgos are effected?

Is there a complete jet kit with everything needed for these modifications? (pods and exhaust)


If there isnt, what would be a good start for the e clip needle position, fuel pilot screw adjustment, and appropriate jet sizes for each circuit?

Im also wondering if it might be a better idea to purchase the jets, needle and seat, and o rings sperately if most of the items in a carb kit will be discarded anyway. My mixture screws are in good shape and the fuel pilot screws are not protruding through the inside wall of the carbs. The needle and seats are showing some wear so i am going to replace those along with all of the o rings.

has anyone used the Keyster or K&L carbs kits often offered on Ebay? Which one is better?

Just looking for some direction...

If anyone has any of these items for sale let me know. :-D

[byrdman76]

Anyone???

Anyone have any input?

[robertbarr]

I will also be tearing the carbs completely apart, dipping them in berrymans and installing necessary parts.

Atta boy! Do it right and you won't be back asking about problems that could have been cured early on. Change the intake boot O-rings too, without fail.

As for the pods: This question arises so often that probably very few people are willing to rehash the subject for the 3,658th time. I suggest using the SEARCH function.

Rebuild kits: most people buy a complete O-ring kit from this pirate:

http://www.cycleorings.com/

(who would also happen to be me ...) and you can find any other necessary parts as needed. Usually the bowls separate without needing a new gasket, and you can get away with spending a bunch less than you would buying 4 kits.

On some of the VM carbs there are rubberized interconnecting fuel tubes that can be tough / impossible to find. Again, try the search. It comes up from time to time.

Overall, I would personally suggest making just one change at a time. Getting that thing dialed in with pods could be extremely frustrating and expensive.

[DimitriT]

Anyone have any input?

You may just need new gaskets and o-rings for you carbs rather than shelling out for the kits. Do a forum search on "Robert Barr O-Rings". When I rebuilt my carbs I used the jets from the kits but alot of people recommend you stay with the stock jets. I used the K&L kits.

You should consider upgrading the suspension. Progressive fork springs are small money but make the bike feel alot more controlled. The other place I would consider upgrades are the tires and brakes. I think this is where you will get the most fun per $$ out of the bike.

[byrdman76]

Atta boy! Do it right and you won't be back asking about problems that could have been cured early on. Change the intake boot O-rings too, without fail.

As for the pods: This question arises so often that probably very few people are willing to rehash the subject for the 3,658th time. I suggest using the SEARCH function.

Rebuild kits: most people buy a complete O-ring kit from this pirate:

http://www.cycleorings.com/

(who would also happen to be me ...) and you can find any other necessary parts as needed. Usually the bowls separate without needing a new gasket, and you can get away with spending a bunch less than you would buying 4 kits.

On some of the VM carbs there are rubberized interconnecting fuel tubes that can be tough / impossible to find. Again, try the search. It comes up from time to time.

Overall, I would personally suggest making just one change at a time. Getting that thing dialed in with pods could be extremely frustrating and expensive.

Thanks Robert,

The bike runs pretty good but top end is lacking. The bike tops out at about 80mph. It pulls pretty good and smooth up until that point but begins to give out around 75 and by 80mph 7500-8000rpm it begins to feel like it has nothing left. It wouldnt be that big of a deal, but i ride the bike occasionally to work and a majority of that commute is on the interstate. The speed limit is 70mph and everyone is typically running 85mph. This sucks when your on a little 550 that I can only hold at 70mph for an extended period of time.

I replaced the intake o rings, aerosol cleaned (not dipped) the carbs, adjusted the float heights, and bench synced/vacuum synced the carbs. They actually synced up pretty well. However I didnt dip them and I now have this voice in the back of my head telling me that i should have done it correctly in the first place.

The ignition (points and condensors) have been adjusted several times with a test light and then verified the settings with a timing light. The coils tested out ok and the wires and caps seem to be in very good condition. The spark on the plugs is decent but its no blue flame. Im hoping the dyna will help the higher RPM issue. Instead of wasting money replacing the points and condensors I figured I might as well up grade to an electronic ignition.

The valves have all been adjusted and I have gone through several spark plugs bringing this thing back from the dead.

The compression is about 120-125 per cylinder.

I brought the emgo filters last night on ebay - I'll make tham work before I spend 150 bucks on the K&N's or i'll go back to the stock air box. Even if they do not flow equally I feel that with a proper vacuum sync i should be able to adjust the carbs to accomodate.

I was mainly looking for some 550 owners input on jet sizes and jet kits for these mods. And or anything else I may be missing.

Thanks for the link, the more i think about it all I really need is o rings, new needle and seats, and jets to accomodate the changes.

Thanks again for the response.:-D

[tkent02]

550s aren't supposed to be that slow...

even with stock airbox and exhaust it should go way faster than that. I never had a problem keeping up on my 550. It pulled hard at the top of the rev range. Find out what's wrong with it before you make any changes. Perhaps a clogged fuel screen or filter or maybe a kink in the fuel line? Sounds like it might not be getting enough gas to run wide open.

[skreemer]

the emgo paper cone filters just need to be tweaked a bit... I'll see if I can find a pict of Nerobro's.... They are just too long on carb #1 and #4 and just need to be bent out of the way of the frame tube...

don't forget when you change the pipes and intake you need to rejet... it's easy to do but not easy to make 100%...

[bradleymaynar]

If the bike doesn't seem to be hitting a proper top end, then perhaps a carb rebuild and synch is what may be needed.

Brad bt

[byrdman76]

Fuel path is straight

even with stock airbox and exhaust it should go way faster than that. I never had a problem keeping up on my 550. It pulled hard at the top of the rev range. Find out what's wrong with it before you make any changes. Perhaps a clogged fuel screen or filter or maybe a kink in the fuel line? Sounds like it might not be getting enough gas to run wide open.

The pet cock was thoroughly cleaned and the gas cap is new to ensure that it is venting properly. The fuel line was increased to 5/16 ID and the new fuel filter was removed and then replaced since it had no effect on the performance.

Thanks for the input though, I will see over 100MPH on this bike heck or high water!

[bradleymaynar]

This may be a stupid comment, so forgive me if it is, but you do realize that a 550 is typically a six speed, right? Like I said, sorry if this is a stupid question.

Brad bt

[byrdman76]

the emgo paper cone filters just need to be tweaked a bit... I'll see if I can find a pict of Nerobro's.... They are just too long on carb #1 and #4 and just need to be bent out of the way of the frame tube...

don't forget when you change the pipes and intake you need to rejet... it's easy to do but not easy to make 100%...

If you could find that picture that would be awesome[-o<. I did an extensive search on the emgos on the 550s before I posted the original thread but really couldnt find anything that was rock solid.

Any idea what individual jet size to go up to for pods and exhaust?