Suzuki 2 Strokes

Is there a noticeable large difference in the horsepower comparing the two ? Reason I ask. In the bike world, 15 extra horsepower is a considerable amount that the 750 has over the 550. However, the 750 also weighs a whopping 130 extra pounds over the 550. Also, a huge amount in the bike world. Those amounts are very substantial comparing the two. Considering both are very poor handlers by today's standards. Adding 130 pounds and only an extra 15 hp, doesn't seem a 750 would be that much better of a bike. Even in that time period. Share your thoughts, if you have owned or ridden both.

pearljam724 wrote:Is there a noticeable large difference in the horsepower comparing the two ?

To be honest - not a lot. The 750 is perhaps better on the highway in a cross wind due to its weight, the 550 is nicer around town, but my seat of the pants dynanometer didn't see a huge difference in power between them.

oldjapanesebikes wrote:

pearljam724 wrote:Is there a noticeable large difference in the horsepower comparing the two ?

To be honest - not a lot. The 750 is perhaps better on the highway in a cross wind due to its weight, the 550 is nicer around town, but my seat of the pants dynanometer didn't see a huge difference in power between them.

What you said. Is what I figured. I'm planning a trip to pick up a restoration project 750 tonight. Having never ridden one. But, wanted to confirm my thoughts. To add to what you stated. Both are very heavy considering their horsepower. The 550 is pretty unstable in small crosswinds. Therefore, I can see what you say about the 750 being true. Also agree with what you said about the 550. For only having 48 horsepower, it's pretty zippy around town. Would be a great bike with better handling and being more agile in corners. I've yet to fit modern tires, which I feel should help a little. None the less, the funnest bike I've ever ridden. And I've had my share.

I've owned both of these in the dim and distant past, and no, there isn't a massive difference in performance. The 750 definitely has the advantage.....there's no substitute for cubes !
I don't think I ever managed to coax an indicated 120 out of my 750...115 was about it, and the 550 was no more than 5 mph behind. Both nice bikes to ride though, and a pleasant burbly power delivery from both.

And as far I can tell a 550 made around 38 at the rear wheel and a good 750 was closer to 47 at the rear wheel on Gibson's dyno and Cycle managed to get 57.3 out of a nicely set up road test M model which I think was at the gearbox sprocket on a Webco Dyno, and is way higher than I have seen at the rear wheel on a Dynojet. That bike was more than half a second faster over the quarter than other contemporary tests, so I'm not sure what was going on with that one.

For sure the old "brochure HP" numbers were exaggerated.

The key difference for the street I think is torque which on a 750 was around 48 on that M and 32 on a 550. Even if we discount the 750 number to "normal conditions" that's still almost 50% more pulling power from the big fat girl compared to her skinny sister. On the street fat girls seem to have more pulling power than skinny girls

Does anyone have the actual weight figures for both?

Has anyone ever attempted to shoe-horn a 750 into a 550 frame? Are the mounting tabs even remotely close?
I don't have a 550, but its pretty common to do this with the Kaw triples.

ja-moo wrote:Does anyone have the actual weight figures for both?

750 wet weight 550 pds, 550 wet weight 420 pds. The rad, extra fuel, larger motor, more oil, larger gauge assembly, additional rotor and caliper, etc. makes up that extra 130 pounds.

I had a 550 for a short time, it felt very heavy, and 420 sounded really low. So I looked up some specs and articles. Seems the last 2 years (76-77) models lost 30 lbs over the early ones, but still showed 441 dry weight so would be in the 450 range with fluids.

It seems the Suzuki Factory did nothing to try and make the GT lighter .. everything is heavy and over built from fenders to carbs they all weigh a bunch .

Suzukidave wrote:It seems the Suzuki Factory did nothing to try and make the GT lighter .. everything is heavy and over built from fenders to carbs they all weigh a bunch .

You're exactly correct. That did not come into play until the mid 80's. The quota in the 70's was quality and reliability. Have you ever had a GT turn signal in your hand ? Just an example of how heavy and well built these bikes were from that era. Nearly every part is heavy metal. But, motorcycles have evolved. They are much lighter and powerful today. There is a good side and a bad side to that evolution of the motorcycle. If you raced or street rode a bike back then, crashed it. 9 times out of ten you could picked it up and continue on. With very little economic repercussions. Many modern bikes are near an insurance total or unrideable after the smallest occurrence because of the lighter materials. Older bikes performed very poorly in handling, cornering, braking, power, etc. Lighter materials is a very good thing when it comes to performance. But, there are negatives that comes along with that. It's nearly impossible to have the best of both worlds. I'm not ignorant or prejudice toward any era make or model motorcycle. I like them all. Appreciate what most motorcycles were like long before they evolved. I also like what most motorcycles have involved into. Comparing era's, they both have their pro's and cons.

Suzukidave wrote:It seems the Suzuki Factory did nothing to try and make the GT lighter .. everything is heavy and over built from fenders to carbs they all weigh a bunch .

I just found what looked to be factory specs on the 550's, 73 to 75 showed dry weight at 471, and the 76-77 at 441 dry weight.