Mike R's GS550/650 bare bones street racer

[Suzuki_Don]

You're engine build was exremely helpful in my build process. Thanks alot

Mike, No probs at all. Glad someone could get some use out of all the stuff i put up.

BTW which camshafts did you use in your motor; 550 or 650.

On the gearing issue; I have not got my bike back on the road yet for a test because of the stripped sprocket bolt, but if I find it is geared a bit high then i can go from the 16T front sprocket to the 15T that came off it originally. It's still in good condition. And that will lower the gearing a bit, but I think 16/45 should be about right. Coming down 1T on the front is about equivalent of 3T on the rear.

[boontonmike]

I went with the 550 cams after reading about the differences it seemed like the high duration would better suit what I'm after.

[Suzuki_Don]

I went with the 550 cams after reading about the differences it seemed like the high duration would better suit what I'm after.

It will be interesting when you get the bike on the road to see what you have to say about the power band. When my bike was a 550 there were three different surge points over the rev range. One at about 3000rpm, a second at about5500rpm and it really took off at 7000rpm. Whereas the 650 cams seem to have an even spread of power across the range with a surge around 7000rpm - but vivid acceleration all the same.

Did you degree the cams, or were you able to time the cams without doing that? How many links did you use between ↑2 and ↑3 on the cam sprockets.

[boontonmike]

It will be interesting when you get the bike on the road to see what you have to say about the power band. When my bike was a 550 there were three different surge points over the rev range. One at about 3000rpm, a second at about5500rpm and it really took off at 7000rpm. Whereas the 650 cams seem to have an even spread of power across the range with a surge around 7000rpm - but vivid acceleration all the same.

Did you degree the cams, or were you able to time the cams without doing that? How many links did you use between ↑2 and ↑3 on the cam sprockets.

I followed the 550 service manual to time the cams to stock with 20 pins from arrow to arrow. I didn't have to degree the cams because everything from the cam setup was off the original 550. Everything lined up perectly. I am also interested in the final result and will keep this thread updated through the whole tuning process until it's dialed along with some videos when complete.

[Suzuki_Don]

I followed the 550 service manual to time the cams to stock with 20 pins from arrow to arrow. I didn't have to degree the cams because everything from the cam setup was off the original 550. Everything lined up perectly. I am also interested in the final result and will keep this thread updated through the whole tuning process until it's dialed along with some videos when complete.

As I said I used the 650 cams, slotted the sprockets and degreed them in. I ended up with 19 pins between arrows to get everything correct. Better wind the motor over a few times by hand just to make sure there are no clunking sounds when you hit that starter button for the first time.

[boontonmike]

Already wound the motor, set the tensioner and used the kickstarter to cycle the motor a couple times and rechecked timing after all that. Everything checks out. No starter button either, running kicker only.

[boontonmike]

Ordered this after going through the reg/rec list for $58 shipped. I decided on this one for its sheer size. Should dissipate heat better than any of the other reg/rec's.

FH-0011AA FET 50 Amps / 100V rating 14.3V - 15.1V which seems to be one of the highest rated. I have plenty of room to mount it either under my tank or seat.





All thats left for my electrical system is a battery, stator, and the wideband before I wire the bike up.

I also got a free H4 conversion from my friends dad. Fit like a glove in my headlight bucket and the beam patterns seem like they should work well. I want not only the engine but all the electrical on this bike to be high ouput and flawless.

The knee pain is going away as is the swelling. I'm hoping by next weekend I'll be more able to work on the bike. This weekend was pretty brutal as far as being immoble and in pain.

[Suzuki_Don]

Already wound the motor, set the tensioner and used the kickstarter to cycle the motor a couple times and rechecked timing after all that. Everything checks out. No starter button either, running kicker only.

Sounds like you've got it all sorted Mike. Good luck with the rest of it. I will be following the thread closely.

[boontonmike]

Sounds like you've got it all sorted Mike. Good luck with the rest of it. I will be following the thread closely.

Thanks alot, good luck on your bike too. From what I recall reading you had a fire misshap and had to do a bunch of work to your bike. Are you still running the 700 piston setup?

[Suzuki_Don]

Thanks alot, good luck on your bike too. From what I recall reading you had a fire misshap and had to do a bunch of work to your bike. Are you still running the 700 piston setup?

No Mike my bike never caught alight. Just the way I worded the thread after I had started it for the first time after the rebuild. "It's Alight" - meaning all cylinders firing and running as planned.

The 700 cc piston setup is just the largest o/s piston available for the 650. It's 1mm o/s which takes the motor out to 699cc to be precise - nothing fancy.

I am currently in the process of changing the rear sprocket and while I am waiting for sprocket bolts to come from Japan I am in the process of fitting the 650 advance/retard mech. unit in place of the 550 unit on the end of the crank. The issue is the 650 unit is longer than the 550 one and the cover will not go back on in its original place without fouling the end of the advance/retard unit. I have to shorten things up a bit.

[boontonmike]

No Mike my bike never caught alight. Just the way I worded the thread after I had started it for the first time after the rebuild. "It's Alight" - meaning all cylinders firing and running as planned.

The 700 cc piston setup is just the largest o/s piston available for the 650. It's 1mm o/s which takes the motor out to 699cc to be precise - nothing fancy.

I am currently in the process of changing the rear sprocket and while I am waiting for sprocket bolts to come from Japan I am in the process of fitting the 650 advance/retard mech. unit in place of the 550 unit on the end of the crank. The issue is the 650 unit is longer than the 550 one and the cover will not go back on in its original place without fouling the end of the advance/retard unit. I have to shorten things up a bit.

Well that's good news that the bike didn't actually light up. I'll keep in mind the 699cc upgrade. How is the piston shape compared to the 650? Also, where do you aquire stock 700cc pistons? I may have a complete Dyna III setup for this engine when I'm finished including the whole crank triggers with mechanical advance unit.

[boontonmike]

I just spent 112 shipped on a NOS 550 stator. A little more than I wanted to spend , but with a bulletproof reg/rec backing it up it should work great and last forever. I have faith in Suzuki over the couple aftermarkets I can find out there.

[brslk]

I'm considering going to kick start only so I may have some questions for you.

Bruce.

[tkent02]

I'll keep in mind the 699cc upgrade. How is the piston shape compared to the 650? Also, where do you aquire stock 700cc pistons? .

I believe he is using the largest available oversize GS 650 pistons, which gives 699cc displacement, not GS 700 pistons. Their shape is totally different, as the 700 has four valves per cylinder.

[boontonmike]

I believe he is using the largest available oversize GS 650 pistons, which gives 699cc displacement, not GS 700 pistons. Their shape is totally different, as the 700 has four valves per cylinder.

Noticed this when browsing the web. Also didn't have much luck finding NOS oversize pistons. Sounds very very interesting tho, as enough is never enough for me.