Wrong carbs on new bike - Screwed??

[jbthomp]

Yeah i learned that one too!! I thought i was getting a good deal on mine at 650$. Only to find out it cost me another 6-700 minimum to get it running and dependable. I don't think there is such a thing as a cheap beater 30+ year old bike. I'm pretty sure they are all money pits.......

 

[Bustedknuckles]

I just cant win with this thing! DynoJet doesnt make jet kits for this bike... im pretty familiar when it comes to cleaning carbs but when it comes to tuning them it might as well be a jet turbine... any suggestions on what route to take on re-jetting this thing?

 

[JTGS850GL]

Yeah i learned that one too!! I thought i was getting a good deal on mine at 650$. Only to find out it cost me another 6-700 minimum to get it running and dependable. I don't think there is such a thing as a cheap beater 30+ year old bike. I'm pretty sure they are all money pits.......

But dam good looking money pits when you get them fixed up.

 

[jbthomp]

But dam good looking money pits when you get them fixed up.

Fo Sho! Mine is turning into a sexy beast! lol

any suggestions on what route to take on re-jetting this thing?

I think the general consensus is getting it running right in stock form then do your changes. I can't speak from experience tho because my bike is still stock. But as many of these as there are out there it shouldn't be that hard to find out which jets you need for pods. Im pretty sure you will need a bigger main but i (think) the pilot can still be stock for pods. There is a thread here somewhere about pods and 4-1 exhaust. But you will have to learn how to do plug chops to see where you are at in the tuning process.

 

[jbthomp]

http://www.thegsresources.com/_forum/showthread.php?t=199275&highlight=jet+gs750
Here it is

 

[koolaid_kid]

First, you MUST rebuild the carbs. Completely, using Nessism's latest guide on BassCliff's site. www.cycleorings.com carries everything you need. I prefer to replace all the JIS screws with stainless steel allen screws when I rebuild a set of carbs.
Second, kit 3314 for the 82 550 Katana should work. Pretty much the same engine. You will need to purchase Suzuki pilot jets, since the DynoJet kit does not come with any. You might be able to get away with using the 650 pilots, since they are only one size bigger, but you would have to lean your mixture screws by about 2 turns if you did.
Third, you can sell your VM carb bank to help offset the cost of getting the proper carbs.
Fourth, when you get pods, the APE pods are K&N knock-offs at about half the price.

 

[Bustedknuckles]

Don't forget about the jetting. I believe the jetting for the 550 and 650 are not the same. According to the fiche:

1980 550 Shows
Main: 92.5
Pilot #40
Needle Jet: X-6
Needle: 4BEL2

1982 650 Shows
Main: 110
Pilot: #42.5
Needle Jet: X-6
Needle: 5C45

So even if you get those carbs you'll still need to get the right jets.

Have you contacted GSX1000E on his offer? Seems like a good option to swap what you have even if it costs a small difference. At least you'll know what you're getting. Maybe too late though if you've already committed to those on ebay.

do you think the fact that it will have pods offset the difference in jets? the main seems kinda far off but the pilot is only 1 size larger. I know everyone preaches keeping the airbox but i have a nice set of K&N's just sitting that i plan on using. and its SO much easier working on carbs with pods vs. the airbox.

Also, i read throught that thread that jbthomp posted, it sounds like the needle will make a huge difference too. Now again, im not asking anyone to do the work for me but im clueless when it comes to tuning carbs. i can rebuild a set no problem. but deciding which mains, pilots, needles, and shims to use... im looking at needles on JetsRUs, they have single taper, double taper, and all kinds of sizes for all kinds of models. I dont even know where to start...

I cant thank everyone enough for their help and advice. Being a member of this forum has taught me so much. Not just about motorcycles but of the kindness and selflessness of people. Thank you all so much! :clap:

I bought the bike for $475, when everything is said and done i will probably have more in the carbs than what i bought the actual bike for... gotta love it!

 

[jbthomp]

1 jet size for custom 4 into 2 exhaust

2 jet sizes for 4 into 1 exhaust

1 jet size for K&N filter (single inside airbox)

1 jet size for drilling out the bottom of the airbox

3 jet sizes for individual filters

2 jet sizes for no muffler (open header)

1 pilot jet size for every 3 main jet size increase

Add up all the jet size increases and subtract one. (Remember they go in steps of 2.5 for each jet size)

This should be a good starting point to go by. You will need to know what jet sizes you have as a starting point. I would start off with stock jet sizes for the 550E then go from there. It looks like you need to go up 3 on the mains and possibly 1 on the pilot. It depends on how many turns out you have to go on the idle mixture screws to decide on pilot increase or not. Anymore than 3.5 turns out and i would increase the pilot size.

 

[jbthomp]

Its going to be trial and error so figure out how to get the carbs out easily because you will have them out a lot. A lot of people don't do pods because they are a pain in the ass to tune right for sure. But like koolaid man suggested. Clean the carbs good. (Strip and dip) Get the right intake manifolds and check the valve adjustments before you attempt any tuning or you will never get it right (ask me how i know).
Here is a copy of the service manual for your bike.

http://www.mtsac.edu/~cliff/storage/gs/GS550_77-82_all.pdf

Everything you need to know should be in there.

 

[Bustedknuckles]

1 jet size for custom 4 into 2 exhaust

2 jet sizes for 4 into 1 exhaust

1 jet size for K&N filter (single inside airbox)

1 jet size for drilling out the bottom of the airbox

3 jet sizes for individual filters

2 jet sizes for no muffler (open header)

1 pilot jet size for every 3 main jet size increase

Add up all the jet size increases and subtract one. (Remember they go in steps of 2.5 for each jet size)

This should be a good starting point to go by. You will need to know what jet sizes you have as a starting point. I would start off with stock jet sizes for the 550E then go from there. It looks like you need to go up 3 on the mains and possibly 1 on the pilot. It depends on how many turns out you have to go on the idle mixture screws to decide on pilot increase or not. Anymore than 3.5 turns out and i would increase the pilot size.

You're awesome! Once i get the correct carbs in the first order of business will be a full strip down, dippin', and a complete rebuild. I will then take a second look at this chart, order those jets, 3-up on mains, 1-up on pilot. (most likely the right ones) and start dialing in from there... My last question is about the needle... Can i use the stock one without severe adverse effects or do I have to get a new one?

 

[JTGS850GL]

Just pick up a Dynojet stage 3 kit for an 82 550 Katana. Dynojet spent a good amount of time getting the needles to be the right shape for pods. The pilots you have in there may work but the worst case scenario would be to buy a set of Mikuni #40 pilots. I'm betting you can use the #42.5 GS650 pilots that will come with those carbs.

One last note... Make sure that you verify the jets that come with those carbs. After 30+ years, these bikes have been touched by many hands.

 

[koolaid_kid]

Busted, in case you were not aware, the problem with pods on CV carbs is the needle. DynoJet spent a lot of time getting the exact taper for maximum performance when on the needle, which is where you will spend the majority of your time. Stock needles have no taper, hence will not yield maximum performance.
As I stated earlier, the 42.5 pilot jets will probably work. Normally you start tuning them with the mixture screw 3 turns out, with 42.5s you want to start tuning them at 1 1/2 turns out (follow the link in my signature for the procedure). I know for certain; I went through the same exercise on my GPz.

 

[Bustedknuckles]

Just pick up a Dynojet stage 3 kit for an 82 550 Katana. Dynojet spent a good amount of time getting the needles to be the right shape for pods. The pilots you have in there may work but the worst case scenario would be to buy a set of Mikuni #40 pilots. I'm betting you can use the #42.5 GS650 pilots that will come with those carbs.

One last note... Make sure that you verify the jets that come with those carbs. After 30+ years, these bikes have been touched by many hands.

Honestly that sounds like a great idea. But maybe this would make things easier AND cheaper... Why dont i just buy a used airbox, throw it on there and buy the right pilot and mains for the 550?

jet kits aint cheap and the new kit + pods would be a "female dog" to tune right? so a fresh rebuild + cheap used airbox + correct pilots and mains would make it much easier to tune AND be cheaper right?

Again, i dont care about maximum performance nor aesthetics. I just want the damn thing to run!

 

[koolaid_kid]

If you are not going for performance, the easiest is going stock. The problem is that it consists of multiple components. The airbox, air filter box, airbox to carb hoses, air filter box cover, air filter, and assorted clamps and hoses.
But then all you would have to do is purchase the proper mains, set the mixture screws as I stated before, and it should be fine.

 

[Bustedknuckles]

I've gone past the point of frustration... ive been looking online for a solid hour trying to find those components but cant find all of them. even on ebay. I have the air filter box already.

I cant find the air filter box lid ANYWHERE. all i can find is the assembly for older models. which if I'm not mistaken wont fit my bike. (just like the older model carbs)

Does it HAVE to have a lid? the older model air filter box wont fit? What about a 650 airbox?

and is it just me or are intake boots absurdly priced?

If you are not going for performance, the easiest is going stock. The problem is that it consists of multiple components. The airbox, air filter box, airbox to carb hoses, air filter box cover, air filter, and assorted clamps and hoses.
But then all you would have to do is purchase the proper mains, set the mixture screws as I stated before, and it should be fine.

 

[koolaid_kid]

You can fabricate a lid using ABS plastic, or even use duct tape.
IIRC the 650 airbox is identical.

air intake box
Looks to be complete with the boots and springs

Yes, they are expensive.
here is a set of of intake manifolds that is a little cheaper

 

[JTGS850GL]

Why don't you PM GSX1000E and see what he had to cover your solution? I think he can help you without a lot of expense and frustration.

 

[Bustedknuckles]

The passage from the airbox to the filter housing on that is oval. Mine is round. Problem?

air intake box
Looks to be complete with the boots and springs

 

[koolaid_kid]

The passage from the airbox to the filter housing on that is oval. Mine is round. Problem?

No idea. PM GSX1000E.

 

[Bustedknuckles]

already did.

No idea. PM GSX1000E.