Cruising at interstate speeds?

So I just recently bought a 1982 xj650 maxim. i've only taken it on the 50mph highways but not on the interstate yet. I'm kinda spooked because my speedo maxes out at 80 and i don't know if it'll hurt the bike to run it at a speed so close to it's "top speed" for long period times. I'm i just being a prissy bitch or will running at such high rpms (5-7k) for long periods of time harm the bike?

 

ha ha.. your maxim will go upwards of 110 mph
they actually run better on Interstates at those speeds
constant speed is easier on the motors
don't sweat it

 

I agree. You can run the bike all day at 9K. It makes quite a whine at those Rs so I always wore ear plugs. That sound will fatigue you after awhile.

I wonder why you have an 80MPH speedo. I'm pretty sure my 82XJ650 went to at least 120. I know I saw the needle fly past 90 a number of times.........

 

My 82 750 Maxim speedo only goes to 80 as well.

 

The imported (U.S.) 650's left the factory capable of 120mph. The 80mph speedo was something yamaha did because of economical issues back then. I Digihub clocked myself at 92.3 and i wasn't at redline. Fwiw shortly after i first got mine i paid a nice ticket for 73 in a 50 (i thought i was going 53). Up until i got the ticket I was like damn this bike is fast.

Edit: at true speed it's still fast enough for me.

Gary H.

 

yea, i wouldn't sweat it. they did the same thing on the Hondas around that time with the speedos.

 

I think the 80MPH speedo was a nanny state thing, around the same time that they instituted the 55MPH national speed limit. The powers that be thought that if people saw that the speedo goes up to 120 then they would be tempted to try to do it. Which is probably true. But the law didn't last long anyway.
I agree with the others that you can run your bike all day long at interstate speeds with no worries, assuming of course that it is in good mechanical shape.

 

Under Carter, and hot off a number of high profile car safety issues, NHTSA imposed that rule with 1978 models thru 1983 IIRC. 85 MPH speedos were mandated in hopes of reducing accidents and consequences, as well as saving gas after the shortages of the 70's. A shortage of actual supporting data prevailed and in the less-government days of Reagan the rule was dropped. It has ZERO to do with what your bike can do. It will go well over 100 and happily cruise into the 90's all day long. Make darned sure your bike, and you, are in the proper condition for either, or they may yet collect that data. The relationship between engine speed and road speed is linear so you can calculate your speed above 85 quite easily.

 

dude sick. thanks guys. has anyone with the 80mph ever thought or done a switch on the speedo faceplate to correctly show its full range of speed? (you could always just take a sharpie to the faceplate).

 

BigFitz has posted some DIY posts on this topics. Search under modifications specifying him as the poster.

 

You cannot just replace the faceplate. The speedometer is geared to show a maximum of 85 MPH, and the gearing cannot be changed without damaging the unit. You can swap in a speedometer with a broader range (this will require some surgery), or mount either a GPS, or a bicycle speedometer to the bike (bicycle speedometers are fairly easy to install and indicate speeds up to 200MPH with very little error).

 

+1.

@k-moe: i was wondering where you were. Glad to see you chime in.

Gary H.

 

The teacher gets very much too busy near the end of a semester. The next two weeks will be used to restore my sanity.

 

Noooooooooooo!!! Too much sanity is bad for business. You're plenty sane. Cheers.

Gary H.

 

Once you get past the idea that "it sounds like I'm gonna blow up", you'll find that your powerband is around 6k - to redline. Once you get used to getting up to 6krpm, and start feeling that sucker pull, you'll havea greater appreciation for what these bikes can REALLY do.

yep, they'll run 8.5-9.5k rpm, and at 85-90 degrees all day, and beg for you to give 'em more. Just take care of the bike and it will take good care of you, too.

Welcome aboard!

DAve

 

ohh that sweet sweet powerband

 

70 seems happier than 55 except for the wind

 

Mine LOVE to roll about 75-80. I don't get as good fuel economy as I do if I stay at 65-70, but it it almost like cruise control at the higher speed but just a touch on the throttle and they're raring to go!!

 

I believe at that time there was an "energy crunch" and all car and bike speeds maxed out at 80 mph

 

I've always had japanese motorcycles hondas kawasakis Yamaha's they all seem to have a 70mph sweet spot on the highway