Yamaha History Question

I just finished reading Chacal's Yamaha history sticky.

Therein it states that the XJ750 Seca and Maxim essentially had identical horsepower and engines, just that the Seca had more sportbike-like styling.

Thing is, I've heard mention that Maxims have 6 gears. I know 550 Maxims had 6 gears and chain drive but did Maxim 750's also get a 6th gear? If so, what is the feasibility of swapping a transmission from a Maxim into a Seca so I can have a 6th gear?

Comparing XJ's to modern rice-rockets is kind of an apples-to-oranges" thing, but does anyone have any experience competing their 550's, 650's and 750's against modern bikes? How did you do? Anyone with the X-varient try this? Did the water cooled version give you extra oomph?

I ask this question because I often hear of our bikes referred to as "heavy" and "underpowered".

Thanks.

 

Sushi,

I guess I can save you some work. The 750 Maxim only has 5 gears. When I first got the bike I spent a lot of time trying to shift into 6th gear until I got used to the fact that it runs at higher rpms.

mikeg

 

I concur with mikeg.
My '82 XJ750 Max has 5 gears and could definitely use a 6th.

 

My 85 Maxim X XJ700NC only had 5 gears and ran a pretty high RPMs.

 

I have run with many diffrent bikes. Harleys to Busa's (slowest to fastest lol)
If someone on a 600cc plus sport bike pulls the trigger your in the dust.
Top speed for us is 120ish while the sportbikes are at 150-160ish
Me and my bike weight 700lbs and the other guys while on their bikes are around 550-600lbs.
They have more horsepower too....
But on a long run, lets say a 250 mile ride, I will jump off my bike and run circles while they are too tired to even talk.

The damn things were built 26 years ago, and still run. Whatcha bit*hing about.....

 

I sure don't find the Seca 550s to be heavy and underpowered. My real world experience has been a surprise to riders of larger-displacement and more modern machines. I had a guy ask me last summer if my '81 was "a 1000 or sumthin'" because of how badly I dusted him at the previous stoplight.

 

This was all very educational, thanks. I guess I don't need to worry about a gearbox swap. 5 is what I got.

 

I personally don't find my xj650 to turn all that fast. My SiverWing turns 6200 at 65 mph indicated. This was hard to get used to but the darn thing just seems to purr all day long at these rpm's.

 

i'm with fitz, mine is a maxim not a seca but deffinatlely not heavy or under powered. Awsome well balanced bike and will easily run with my bosses 91 nighthawk 750.

 

The Maxim/Seca is a predecessor to the current day sport bike engines. Our engines will turn 9500 RPM and the newer sport bikes can easily do 12,000+ RPM.

I am not a big fan of running the bike at the really high RPMs because of the engine breaking. If you twist the throttle off too quickly you can launch off of the front of the bike. It scared me when I rode the parts bike home in first gear. I was going 35 mph and went to slow down and almost went over the front.

The horse power is proportional to the RPMs. That works for breaking as well as acceleration. BE CAREFUL

 

others have told me that our Xjs Secas 650-750 is about the same performance as the newer Kawasaki 250 ninjas, that kind of gives me an idea how it would compare to modern day 600cc sports bike.

 

The ability of the rider plays alot. I have a couple of buddies with bikes that according to the magazines should clean my clock. I smoke them

 

The 250 Ninja is 45 HP at 11,000 RPM and 330 lbs.
The 650 Max is 71 HP at 9400 RPM and 450 lbs.

The Ninja will have to rev much higher to accelerate and keep up with with a 650 maxim.

A Seca 900 at close to 100 HP would smoke the 250 Ninja badly.

My 650 Max seems a tad light weight in strong winds. The Ninja at 120 lbs lighter would have to get shoved around a LOT in strong winds.

 

My neighbor bought a '07 Ninja 250 to replace his Chinese scooter. He sold it within a month. He said it was gutless, and felt like a pogo stick at highway speeds. He then got a '91 Ninja EX500, which is quite a bit more fun.

 

My 650 has alot of snap for a 650 and I'd say that's about were it ends.
Even bikes of this era smoked them.
My V65 was 540lbs, 121hp, that bike flew.