Mike R's GS550/650 bare bones street racer

[boontonmike]

I started this post in the Appearance section a year or so ago and decided to Remake the thread in here for obvious reasons. I copied and pasted my first 3 post ( which happen to be about a year apart from each other) and condensed it here to continue...


Hey guys! First off I'd like to say "Hi" and "Whats up" to everyone on the board. I've been a lurker here for about 2 years. Finally signed up a couple days ago as I've started doing a photo log of my project.

Two years ago I bought the bike. Typical decent running/decent looking bike. It started its life as a bone stock 1978 GS550 where it got one year of stock riding under its belt. Last year I started the tear down process and amongst other projects it hit the back burner. This year me and a buddy re-did his garage and set up shop where things are starting to get more serious.



OK, onto the bike as it sits now. As of now I have it torn down quite a bit and have been working on using the cut off wheel and grinded to remove all bracketry and whatnot that will no longer be of use. I will be rebuilding the carbs and going Pods and a jet kit to go along with a 4-1 exhaust (I know how typical). The plan is to do a minimalistic cafe / around town bike.







I will try and keep this updated as much as possible with pics and info on any modifications I plan to do. Coming from building swapped engine turbo cars and chevy v8 swapped camaros I'm glad to finally be involved hobby like GS's. It's going to especially be more friendly on my wallet! Cheers everyone and thank you for reading.

[boontonmike]

My project came to a halt over the past year due to my job slowing down to a near crawl a couple of months. I've started to work full time again the past 2-3 months and luckily came across a 1991 GSX-R 750M ( best oil cooled motor ) off of craigslist . So now my plans changed a bit. I also scored a GS1100e aluminum swingarm off of Ebay finally after being sniped on 3 previous occasions.

After almost completing the 550/650 swap ( All thats left is adding the cams, timing them, and doing a valve check) and coming across the GSX-R I've opted to wedge the 750 SACS motor into the 550. Who wouldn't being that its just about double the horsepower. As we all know from Tim the toolman Taylor MORE POWER ! . haha.

I'm at a somewhat fresh start in my basement here. It's tight and I'm working on getting all my tools and parts sorted and get a bench/workspace setup. I'll soon get pictures of all the goodies so you guys can see some progress and know I'm not giving up.

I'll soon be putting up a bunch of parts for sale that I won't be needing like the 550/650 engine and whatnot.

Alright I'm starting to get carpl-tunnel from typing this much so I'm done for this update.

Cheers!

[boontonmike]

Hello Everyone,
It's been a long drawn out road for this project due to a second relocating to my other friend Bills barn that we turned into a project garage for Bill, my other friend Ken and I. On top of this my job went down the ****ter the past year so works been on and off when I can get it. Now onto the bike stuff.

I've made some progress along with some more changes in design. I've opted not to use the oil cooled motor as I found out it was 1127 that was swapped into the 750 parts bike I bought. As cool as it would be to have 150 HP i wasn't really interested in seeing how much the old 550 frame could flex. I've retreated to the 550/650 engine and am using GSXR mikuni 32mm CV flat slide carbs. I just this week ordered some carb intake boots to make it fit together and will be porting out the head ports to match the opening in the intake boots.

As you can see here I finally got the front end mocked up and am waiting on an ALLBALLS shipment with my new headstock bearings. Incase you are doing the same swap the measurements for the bearings are 25 x 48 x 16 upper and 30 x 48 x 14 lower. I am going to have to do fork seals unfortunatly but I will put that off until more funds come in and I'm closer to road worthyness. The rear shocks are 1.5" over stock length EMGOs( yeah they are cheap but they'll do til the future when i can get better). The rear swing arm is a GS1100e which required me to drill the frame holes for the swingarm bolt 1mm oversize. The tank I picked up from a guy an hour away for 50 bucks which I believe to be an 80-82 750 or 1000(1100) e tank. fits the style perfect. Rearsets are off the 92 GSXR parts bike i bought and i plan to chop them a bit to give a smaller more clean looking back plate design.



This is a picture from before i got the forks in but was mocking up the seat and rear tail section. I'm sing a chopped up modified stock foam and rear tail piece which after staring at for a while look stunning in my eyes.



I'll have more pictures and updates in the near future as I've been doing alot of work finally on it and have been snapping pictures at every possible point in the project.

[Tim Tom]

I'm digging the stance and the tank tail combo. It look's like its gonna be a rocket when its all together. Cool.

[Erki]

I like it so far.

[Charlie G]

I'll think I'll stick around for this one. Good start.

cg

[boontonmike]

Got the bearings in the mail today. Props to Allballs, I ordered them at noon yesterday and they were here by noon today. I can't believe how quick the install went. The hardest part was getting the old race off the stem but that was only about 10 min. of me and bill hittin each side with some chizzles and a hammer. It went together perfectly along with some waterproof thick grease. All thats left on the front end is to remake up the steering stops which shouldnt take too much time.

Mocked up the top triple, guages, and some other small bits you cant really see in the picture.

[boontonmike]

So where should I start. I've done quite a bit since my last update.

Carbs:

I got these in the mail, 88 GSXR 750 intake boots which I though would line up with the 92 GSXR750 ones I already had. Turn out 2 from each set did line up spacing wise and in a nice horizontal line. Only problem was the 88's were 1/4" shorter then the 92's.



Luckily I had the stock 650 boots which are an aluminum base moulded into rubber. An hour of cutting filing and drilling on 2 of the 650 boots turned into perfect spacers (well within 1/16th" which should do just fine). The final step is to port match the head inlet to the carb boots (as seen on other members 650 head projects).





I think I finally narrowed the carbs down to BST33SS (or 32 ) Mikuni flatslide CVs off of late 80s GSXRs. Information has been pretty skimpy on them Google-wise. Other then the lack of avaliable information I feel like they are going to work out great using my non-scientific gut instinct reasoning. ( i.e. Dyna 2000 with 2.2 coils, K&N pods, open exhaust and other things here and there ) Worst case scenario I switch back to the 32mm Mikunis that came with the 650 head.

[boontonmike]

Next on the list was minor. I removed the iginition Key from the top triple. I'm not positive what I'm doing with the whole dash yet but I want to include the GS550 1-6 gear indicator lights and have some other cool little ideas I'll reveal if I ever do them.



I know you can't see it well, but I found the top dust shield to go over the top bearings and under the top triple. A small but very satisfying part to have there knowing my new bearings will stay clean.



My next mission was to modify the Valve Cover specifically the cam cap mounts. I just decided I didn't want them at all nor the mounts. So off they went. Still need to do a little filing which I'll do when I pull the valve cover off to clean up and check the valve clearance.

[Tim Tom]

Good thinking with using the old aluminum boots as a spacer, although I hope you did some good sealing on that joint. If your boots leak the bike will never run properly.

The triple trees and gauges look nice, although you could loose the circle that used to hold the ignition. Then you'd have a nice clean top triple.

[boontonmike]

Last One til my next update:

I recieved the 4.5" GSXR rear wheel from Koto here (who did a great job selling it to me). I didn't want a 180 and to deal with all the clearance issues. Plus, I'd like to keep the weight down and there must be a decent difference between a 5.5" wheel and 180 tire VS a 4.5" wheel and 150 tire. 150 should Be plenty of tire for the bike while keeping it agile yet being aesthetically pleasing.



Still need to double check my front to back alignment and after making my brain numb reading the dozen different methods and why each one is superior I think I've figured out a method that should work for me. As is it seems pretty close already.



I'm using the trick GSXR rear brake caliper, bracket, and torque arm and mounting it to the frame. This goes along with the original design of the system using a freely spinning caliper bracket and a frame mounted torque arm to redirect the torque during breaking to prevent effect on the supsension. The searches on that whole system was another brain melter as I learned alot and also questioned how much of an effect it can really have. I went for it anyway. The torque arm being aluminum is also a great weight drop over the stock steel and the caliper being mounted below should lower my center of gravity that little bit more.



That's all I got for now. Hoping to get some more in before all the Halloween madness.

[boontonmike]

Good thinking with using the old aluminum boots as a spacer, although I hope you did some good sealing on that joint. If your boots leak the bike will never run properly.

The triple trees and gauges look nice, although you could loose the circle that used to hold the ignition. Then you'd have a nice clean top triple.

Like the way you think. The seal should work because the spacer retains the origional O ring to the block and the new intake boot has an O ring to the spacer. In theory It should seal up and I will be using all new O rings all around.

I was thinking about chopping that circle out and using the 2 mounting screws to mount a small bracket for the gear indicator.

[boontonmike]

One last thing:

I dug up the stock kickstand and to my delight It hold the bike at the perfect angle with no modifications. It's the little things in life. (It's also just a cool shot)

[boontonmike]

halloween



Progress has been stopped due to a halloween party in the shop stalls. looks pretty cool.

[boontonmike]

Did a couple more things in the past week or so:

Did a port match from the intake boots to the head ports:
Marked and Before any dremel action:



Good view of the spacers I made next to the stock head port:



Partway through:



All done:





Took me about 3 hours taking my time with occasional breaks. Was my first go at any kind of porting so I took it easy. I think it came out pretty good. I probaby could've gone a little more but I was being conservative.