The GT 550 J/K/L/ iron cylinder versions are listed by Suzuki at 48 HP whilst the larger bore / longer stroke alloy cylinder GT 550 M/A/B versions are listed by Suzuki at 54 HP @ 7,500 RPM with peak torque given as 44 Foot / Pounds @ 5,000 RPM. The M/A/B version has a totally different engine that shares few common parts with the J/K/L versions. The pistons, gears, etc. are all different which is something to watch for when hunting down these parts. Top speed of the A/B version was 128 MPH - 3 MPH faster than the GT 750 M. The fastest I toom my GT 550 B was about 118 MPH (allowing for Japanese speedo optomism), which despite a Dresda swinging arm, had the bike do a monster lock to lock tank slapper after hitting a dip in the road that was only brought under control by brute force and careful de-throttling. I never took it that fast on a public road ever again as it takes a huge amount of spincter control by the rider. Yes, the frame can be felt flexing by the rider at high speeds hence the nickname the well deserved magazine nickname, "The Flexy Flyer". I also had a friend with a cafe race GT 550 J back in the day and his was always refered to as, "Ex-Lax" for very good reason!!
That is Hilarious, My Dad said something similar about the Kawasaki 2 stroke triples, not that the frame flexed, but the need for excellent sphincter control!
+Gixxerman 001 The other factor is that good old 4 star leaded petrol had a vastly higher energy (higher calorific value) content than the modern unleaded ethanol crap we have to rely on now. Lots of people have noticed that bikes built to run on unleaded suffer a 15 to 30% drop in performance when run on modern fuel. I've noticed it on many bikes and it seems to focus on a lack of top end go. I ran one of my classic 2 stroke bikes on 5 Litres leaded 4 star 2 years ago in a test run and it was transformed into the rocket ship it used to be..... until I filled it back up with unleaded. Fun while it lasted.
Never ever had and probs good tyres good brakes and good suspension and lower the forks helps my bikes were like on rails and the frame never flexed or tank slapper lots of great wheelies and yes they say widow makers I had they will kill you had lots of good fast runs scare the shot undertaking best bikes ever
MrSuzukigt550 super interested to see what you did and how it all went. I’m about to reassemble my motor today and my goal is 65/70 hp but still be street rideable so no alcohol. Need all the tips I can get.
Please explain the mods you did. I’m very interested as to what was worth the money. Balancing cost $350 and does nothing and would like to know stuff like that ahead of time.
I'm kinda weirded as to why the fan is behind the RAM air system, all of my GT's & I had the full set at one point, all went forward, I don't think I've ever seen one go in reverse. I too would have thought there would be more.
43 HP is very Weak. 1975 RD350 100% Stock = 39 HP and is a lot lighter in weight at 342 wet US Pounds. In 1983 my 1975 RD 350 (USA Spec) made 54.8 HP and was 289 pounds US. Yes it Was my Daily rider averaged 70 miles per day.
Middle piston it's bull shite I had kh400 kh 750 gt 380 gt550 and I used to ride top speed and I never had the middle piston hole on any of my bikes and it was put about by Honda owners
The GT 550 J/K/L/ iron cylinder versions are listed by Suzuki at 48 HP whilst the larger bore / longer stroke alloy cylinder GT 550 M/A/B versions are listed by Suzuki at 54 HP @ 7,500 RPM with peak torque given as 44 Foot / Pounds @ 5,000 RPM.
The M/A/B version has a totally different engine that shares few common parts with the J/K/L versions. The pistons, gears, etc. are all different which is something to watch for when hunting down these parts.
Top speed of the A/B version was 128 MPH - 3 MPH faster than the GT 750 M.
The fastest I toom my GT 550 B was about 118 MPH (allowing for Japanese speedo optomism), which despite a Dresda swinging arm, had the bike do a monster lock to lock tank slapper after hitting a dip in the road that was only brought under control by brute force and careful de-throttling. I never took it that fast on a public road ever again as it takes a huge amount of spincter control by the rider.
Yes, the frame can be felt flexing by the rider at high speeds hence the nickname the well deserved magazine nickname, "The Flexy Flyer". I also had a friend with a cafe race GT 550 J back in the day and his was always refered to as, "Ex-Lax" for very good reason!!
That is Hilarious, My Dad said something similar about the Kawasaki 2 stroke triples, not that the frame flexed, but the need for excellent sphincter control!
+Andy Reid Yeah but those were always (like everyone else's) 'just' crank figures, 43bhp at the wheel (on a 30+yr old bike) sounds decent.
+Gixxerman 001 The other factor is that good old 4 star leaded petrol had a vastly higher energy (higher calorific value) content than the modern unleaded ethanol crap we have to rely on now. Lots of people have noticed that bikes built to run on unleaded suffer a 15 to 30% drop in performance when run on modern fuel. I've noticed it on many bikes and it seems to focus on a lack of top end go. I ran one of my classic 2 stroke bikes on 5 Litres leaded 4 star 2 years ago in a test run and it was transformed into the rocket ship it used to be..... until I filled it back up with unleaded. Fun while it lasted.
Never ever had and probs good tyres good brakes and good suspension and lower the forks helps my bikes were like on rails and the frame never flexed or tank slapper lots of great wheelies and yes they say widow makers I had they will kill you had lots of good fast runs scare the shot undertaking best bikes ever
Geez, my bone stock RD 400c made 35 hp out of the box, I think that kid should do a check of his build. 🇨🇦
the guy running the dyno says 42.9hp at the end. kind of weak for a 550
my '74 GT550 pulled 63hp (RW)after an extensive rebuild in "76: Squished and 3 pieced head, ported, re-aligned intakes, 34mm Mikunis, Car coils, J&R chambers...and ridiculous tuning.
Next year my GT 550 K will have 80 hp in the engine...!!!
MrSuzukigt550 super interested to see what you did and how it all went. I’m about to reassemble my motor today and my goal is 65/70 hp but still be street rideable so no alcohol. Need all the tips I can get.
Please explain the mods you did. I’m very interested as to what was worth the money. Balancing cost $350 and does nothing and would like to know stuff like that ahead of time.
How did you manage ti keep the modded engine cool? I bet that air cooling was not the best
It was a while ago, but if i remember right it made ~45hp. It wasn't tuned right though.
I'm kinda weirded as to why the fan is behind the RAM air system, all of my GT's & I had the full set at one point, all went forward, I don't think I've ever seen one go in reverse. I too would have thought there would be more.
id like to know what rims/wheels and front forks were used on this bike? id like to start a t500 project and looking to modify
What forks are on the GT.. i assume GSX?
42.9 rear wheel HP sound about right for a GT550 with skinny pipes. They only had 48.5 crank shaft HP to begin with.
48.5 HP on the J/K/L engines, 54 HP on the M/A/B all alloy nickaseal bored engines (different bore & stroke).
im sorry i didnt hear the dyno numbers what did he say
About halfway through they plug in the dyno....and oh yeah the fan too.
Stock GT 550 M/A/B is supposed to make 54 HP running on 99 RON leaded petrol. Somehow this bike has lost 12 HP!!
Yes. It lost it in the primary, gearbox and final drive. You're comparing crank hp to rear wheel hp.
The engine makes 50hp at the crank stock so the dyno shows that even with chambers and pod filters you gained zero!
what was the result?
Great job!
43 HP is very Weak. 1975 RD350 100% Stock = 39 HP and is a lot lighter in weight at 342 wet US Pounds. In 1983 my 1975 RD 350 (USA Spec) made 54.8 HP and was 289 pounds US. Yes it Was my Daily rider averaged 70 miles per day.
a 550 3 cylinder two stroke at that..that reading cant be right
Middle piston it's bull shite I had kh400 kh 750 gt 380 gt550 and I used to ride top speed and I never had the middle piston hole on any of my bikes and it was put about by Honda owners
you've got to be careful with two strokes on dynos can cook the pistons and seize the engine on the off throttle real quick..
Only if left on over run ; the guy was correct he pulled the clutch and lightly revved
That's why we used to put some oil in the petrol at every fill just to with closing the throttle
THAT BIKE IS FAST
Cool as fuck pal....nice work
Fixed. thanks.
Much more of that and there would be a hole in the middle piston.
wow, nice
its a 2 stroke
Most 2 strokes are.