Speed question....

Hi to all of you,

I just signed in as a new member to this forum.

I am a new XJ650 Maxim owner (51 years of age, living in the Netherlands) and bought my '82 Maxim 5N8 (that was imported from the US in '93) about a week ago.
It's in a pretty bad cosmetic shape but I did not yet encounter any technical problems......
There is one question about this bike that I can't find an answer for: what's the 'topspeed' of this bike?
The speedometer has a limit of about 80mph / 130kmh but as for what I've read so far it has the same engine as the Seca-model that according to the found specification has a topspeed of about 170kmh.

Could anybody please clarify this to me?

Thanks in advance!

Jos

 

In the 80s the national speed limit in the states was 55mph (90kph).

At that time the powers that were mandated that the speedometers only read to 80mph.

Top speed of 170kmh sounds about right.

 

Aren't the Maxims geared slightly different than the Seca? Such that the Max would have a slightly lower top end but quicker acceleration? I don't know, just asking...

 

I remember doing 110 mph on that bike when it came out, but ended up buying a 82 750 had better rocket take offs

 

I vaguely recall that the original specs stated a 1/4 mile run at 12.6 seconds at a speed of 126 mph.
Not sure what that translates to in kmh.

 

It's my understanding that Maxims are geared slightly taller in ratio than the Seca. This would provide a better "cruising" experience. But I really would have to ride the Seca to see if that mechanical characteristic truly exists.
I do know that a Maxim will damn near pull the front end off the ground in the first 3 gears when pegged. (i don't know this from personal experience......)

 

I know my 81 seca 750 tops out at near 130 mph... no idea what that is in Km/h though. :-/

 

The Maxim is geared taller by 1 tooth to make up for the shorter rear tire/rim ( 2 inches) so a Seca rear rim on a Maxim would get rid of some revs at cruising speed.
The 12.6 Second quarter mile would be for the 750 with Jay Gleason on board at 110 pounds, on a new bike with a tuning crew.
Our fat butts on a 650 that's not spot on would be in the 15 's.
170 = 105 ? It should go a little faster than that, but it will seem like an eternity to hit redline in top gear (126 MPH??) laying on the tank.
You can buy a different speedo, as they seem to be very swappable.

And welcome to the site Jos !

 

Thank you for clarifying that. I was unaware that the Seca had a taller rim than the Maxim.
There are a lot of aftermarket speedo's available too. One member pointed out this site to me not too long ago:
Electrosport
Looks like some good stuff there too.

 

Hey I don't have a fat butt! My girlfriend says I have a cute little butt :lol:

 

That's gotta be one of the thing's I love about being a skinny little punk ... my motorized machines haul around like I'm not even on board!

 

Yeah Dude about the skinny butt. One thing though...at 5'5" and 140lbs....I'll never be able to ride one of the big full dressers :-(

 

I was riding a harley fat bob last night, 800 ish lb bike. I'm 6'2" 125 lbs, lol.

 

Ive got a europe gauge cluster on my '81 550 seca. the highest speed posted on the speedodometer is 140MPH. I have been 145mph on mine (I had another rider keeping speed on his bike) but it took about 5-7 miles of straight flat road to get there. This is with a barnett clutch pack and open exhaust. I would say most anyone could hit 130-135mph with enough road on a maxim or seca

 

my '82 750 speedo was off by 20% even after cleaning / lubing both the cable and the needle. Mine said 50 when I was doing 59.4 -- ouch! I got one of these:
http://www.jensonusa.com/store/product/ ... puter.aspx
good to 125 MPH i believe. There is a wireless one, too.

 

i'm lusting after one of those electrosport ones myself....

 

I'm not quite sure how to put this so I'll just be straight forward: NO WAY. With stock gearing the fastest the Seca 550 is gonna get in top gear downhill with a tail wind at redline is THEORETICALLY about 116MPH. A Seca 550 realistically tops out around 108-112MPH, which is plenty fast enough for that little bike. The motor simply can't spin enough RPM to hit 145 with stock gearing.

 

Thanks to all for the provided information (and the words of welcome from TimetoRide)!

My conclusions after reading all the information (correct me if my interpretation is wrong...):

- the topspeed of the Maxim might be somewhat below the topspeed of the Seca
- the maximumspeed as shown on the speedometer isn't the topspeed but was the result of legislation in the US at the time of introduction of the motorcycle

I'll start looking for a 'European speedometer' that can deal with a theoretical topspeed of about 220 kilometers (137mph)

Jos

 

I got a 1979 Yamaha speedo (from an XS, I believe) that goes to 120mph and I gutted it. I plan to use the guts to replace the Reaganometer in my '83 550. If you get one from a different model that goes to 140mph you could probably do the same. From what I can tell all Yamaha mechanical speedometers from around 1978 thru the 80's are physically identical internally in terms of the actual size of the instrument body, mounting points, etc. (Some have oddly shaped faces.) I'm also experimenting with swapping the odometer drum over to maintain the correct mileage. Photographing everything as I go, will post up the successful aspects.

 

+1 lol