JohnnyL's 1980 GS550L Cafe Build

[steve murdoch]

Congrats on finally getting it sorted.
You have WAY more patience than i do.

[JohnnyL]

Finally success!!! So here is what I have done.

Purchased a rack of 1979 GS550 carbs(VM22SS) from ebay. Chem dipped and cleaned thoroughly. Purchased new o-rings from cycleorings.com. Purchased new factory needle and seats, carb boots and bowl gaskets from onlinecycleparts.com. Purchased a 1978 GS550 head from ebay. Cleaned the head thoroughly and painted in the wrinkle black finish. Lapped the valves. Reassembled the engine with the 1978 head and set all correct valve spacing. Rebuilt the carbs and set the fuel pilot at one turn out, put in 17.5 pilots(15 is stock). Replaced the stock 80 main jet with 92.5 mains. Set the air mixture screw at 1-1/2 turns out. Set all float heights to 26mm without the gaskets in. I also raised the needle heights one clip. Installed the newly built carb rack onto the bike and installed velocity stacks. I decided to go with velocity stacks because this bike is a hot rod now. It won't be ridden tons of miles so I'm not worried about running without good filtration. The velocity stacks do have screens on them. I decided to ditch the vacuum operated petcock and go with a Pingle Petcock. I hated that I couldn't shut the fuel off and run the bike till the carb bowls were dry. I blocked off #3 carb vacuum port and fired the bike up. Holy *@%^$*@%^$*@%^$*@%^$ folks! She fired right up and purred like a kitten. I just got back from a quick run on the bike and man it runs good. No flat spot at 6000 RPM and revs out REALLY smooth and it sure idles nicely.

I will get some pics up here soon of the new carb setup. I plan on going for a ride this afternoon with my son and his cafe'd 69 CL350. I will be listening for backfires on decel indicating a lean condition. When I get time, I would also like to do some plug chops.

I couldn't be happier! This bike finally runs good! Yes!

[93Bandit]

I'm not an authority on the 550's, but I know that VM and CV carbs are not interchangeable on 850s and 750s due to spacing and diameter of the carb ventures. I assume it's the same situation for 550s. You likely won't be able to find carb boots to make it work either.

From what I understand, you need to swap the head with the carbs if you want to do the conversion.

I don't recall the manufacturer name, but someone makes "stage" kits for tuning CV carbs that many on the forum have used with a degree of success. I suspect that would be the best route to go.

I'd wait until more of the knowledgeable guys chime in.

[steve murdoch]

Love the Yammie. I can see why the GS didn't get much love.
They sound good too.

Good luck with the VMs.

[JohnnyL]

Hey there everyone. Sorry I haven't been around. I know I kind of just fell off the face of the earth for awhile. I ended up buying a new bike early in the summer. I purchased a brand new 2019 Yamaha MT-09. Man is it fast.

Anyway, I messed around with the GS550 all summer(when I wasn't working or riding the MT-09) and could never get that silly thing to run right. Sometimes would idle, sometimes wouldn't. Also choked and coughed trying to get over 6000 RPM. Revved out nice but just didn't run right. I did a lot of reading on carbs and realized that CV carbs just don't like to run with pod filters.

I don't want to go into winter with this bike still not running right so I am going to attack this one more time in the hopes that I can get this thing to run properly. So here is what I have done. I purchased a rack of VM22SS carbs from eBay that are from a 1979 GS550. They are filthy dirty and need massive cleaning. I ordered o-rings from cycleorings.com and also ordered new factory gaskets from onlinecycleparts.com. I have already broken down the carbs and disassembled them in preparation for cleaning.

The VM22SS carbs are slide carbs so I won't be dealing with vacuum carbs anymore. They should run better than the CV carbs with pod filters. Right? LOL.

I have yet to remove the CV carbs from the bike to see if the VM rack will even match up. I might have to buy new boots?

Anyway...I'll keep you posted.

[JohnnyL]

This is an amazing build,man. You should be very proud of the result! When I was reading through the thread and saw the first muffler (the black one, it looks just like my Kerker exhaust from the mid 80s), I thought you should try going the same route as med and ditch the muffler and build it into the header:

https://www.thegsresources.com/_forum/showthread.php?236916-1981-gs750-(gs750e)-Retro-Racer-project/page12

But when I saw you put the chrome cone muffler on, it fits the bike perfectly. If I could comment on one thing, I would probably paint the gold reservoir on the rear shocks (I see your son did on his). That's maybe because I live in Norway, and Ohlins-dampers are from Sweden. They pretty much patented the gold reservoirs/dampers and anything that resembles them looks like a knockoff to us scandinavians. I had the same rear shocks as you, as I really think they look awesome, but i couldn't get to grips with the looks. You seem creative with colors so I think you could make them look even better than they do now Or keep them gold, it's your bike!

Other than that, I'll say it again; awsome bike(s)! I'll probably steal a couple of your ideas for my own bike

PS: I also noticed there was a discussion on the money spent.. when you keep the bike for yourself it counts as a hobby, and no hobby is cheap. At least you don't spend the money on an expensive golf-club membersip and green-fees

Thanks Lars. The gold rear shocks still don't sit right with me. The whole gold theme was designed around the front EBC brake disk. When I ordered the front brake disk, the picture showed the hub of the disk as being gold. I thought that would tie in nicely with the gold chain and so I decided to go with the gold shocks to tie it all together. But when the EBC brake disk showed up, the center wasn't gold! It was just metal colored. I guess the specific GS550 disk doesn't come in gold. I may end up swapping out the rear shocks for either black or red/black. But if I remember correctly, the red/black ones also have some silver(shiny aluminum) in them.

The stainless reverse cone muffler sounds pretty amazing. It sounds like a race bike. I couldn't be happier with how the exhaust came out.

[steve murdoch]

The CL is lovely.
It has a long time since i could ride in that position. Kids today.

[LarsKroghStea]

This is an amazing build,man. You should be very proud of the result! When I was reading through the thread and saw the first muffler (the black one, it looks just like my Kerker exhaust from the mid 80s), I thought you should try going the same route as med and ditch the muffler and build it into the header:

https://www.thegsresources.com/_forum/showthread.php?236916-1981-gs750-(gs750e)-Retro-Racer-project/page12

But when I saw you put the chrome cone muffler on, it fits the bike perfectly. If I could comment on one thing, I would probably paint the gold reservoir on the rear shocks (I see your son did on his). That's maybe because I live in Norway, and Ohlins-dampers are from Sweden. They pretty much patented the gold reservoirs/dampers and anything that resembles them looks like a knockoff to us scandinavians. I had the same rear shocks as you, as I really think they look awesome, but i couldn't get to grips with the looks. You seem creative with colors so I think you could make them look even better than they do now Or keep them gold, it's your bike!

Other than that, I'll say it again; awsome bike(s)! I'll probably steal a couple of your ideas for my own bike

PS: I also noticed there was a discussion on the money spent.. when you keep the bike for yourself it counts as a hobby, and no hobby is cheap. At least you don't spend the money on an expensive golf-club membersip and green-fees

[Rich82GS750TZ]

Beautiful. The shadow outside the red stripes make them pop right off. Awesome.

[JohnnyL]

Still trying to figure out why my bike won't rev over 6000 RPM but we finally got my son's tank and tail back from paint. His bike is 1969 Honda CL350 that he bought for $650. The bike was a mess when we got it. We went through a similar process as my bike and rebuilt the entire motor and chopped the frame. I painted the frame myself and the engine. The bike never really ran right. It ran good but just not great. I finally did a compression test and cylinder one was only 120 psi while cylinder two was at 160. I tore the motor down and repainted it again but this time I painted it with a wrinkle finish. I then replaced the rings on cylinder one and rebuilt the motor. The exhaust was ridiculously loud before so I bought a MAC two into one exhaust and cut it up to accommodate a stainless steel reverse cone. The exhaust is still loud but it's not right underneath your leg and actually sounds a lot better. Bike runs incredible now.

I also redid all the wiring again with the knowledge I gained from Brian Wringer and this time put a Motogadget Blue on the bike.

Here are some pics.

When we bought it:



First rendition:




Second rendition:




Incredible paint work by Corby Concepts:

Thanks Johnny - being a fairly new GS owner, I had no idea the Z1 site existed. You just solved some of my problems.

Looking forward to you getting the kinks worked out on your bike. Damn good looking build!

[JohnnyL]

Johnny - awesome project! Keep up the persistence ...

Question please - is that the original 4-1 header? And where did you get the peeshooter exhaust?

I'm planning a 850 rebuild and trying to identify and acquire pieces and parts I want to upgrade.

Thanks for any help.

Thanks! The 4-1 header is a Mac. I purchased the reverse cone quieter exhaust from Z1. https://www.z1enterprises.com/18-sta...2-exhaust.html

I've been messing around with the jetting. I currently have 107.5 main jets and it still doesn't want to rev much past 6000 RPM. I have ordered 105 and 102.5 mains. The plugs look rich so I think I am still rich with the 107.5's.

Johnny - awesome project! Keep up the persistence ...

Question please - is that the original 4-1 header? And where did you get the peeshooter exhaust?

I'm planning a 850 rebuild and trying to identify and acquire pieces and parts I want to upgrade.

Thanks for any help.

[JohnnyL]

I have Sonic Springs on all my bikes. The biggest difference I noticed right away is less brake dive; the front end is so much more stable and predictable under braking.

I had Progressive brand springs on my GS for years, but they have a rather low spring rate; they're biased toward comfort and a lighter rider. To just get sag in the right ballpark, I had to use a huge amount of preload. Once I learned about straight rate springs, I ordered up a set from Sonic and the difference at all speeds was startling.



Oh, and we're gonna need some pics of your son's Honda... this is a Suzuki forum, but I think the folks here would love to see more.

The Honda is coming along. The engine is painted, I fabricated a custom exhaust for it, put on an M-Unit with 100% new wiring, new gauge and new rings on cylinder one. The gas tank is at the body shop and I should be picking it up today or tomorrow and then it will go to Corby Concepts for a new paint job along with the seat tail.

I will definitely post some pics of it when it's done.

[bwringer]

I have Sonic Springs on all my bikes. The biggest difference I noticed right away is less brake dive; the front end is so much more stable and predictable under braking.

I had Progressive brand springs on my GS for years, but they have a rather low spring rate; they're biased toward comfort and a lighter rider. To just get sag in the right ballpark, I had to use a huge amount of preload. Once I learned about straight rate springs, I ordered up a set from Sonic and the difference at all speeds was startling.



Oh, and we're gonna need some pics of your son's Honda... this is a Suzuki forum, but I think the folks here would love to see more.