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-   -   71mpg, 75mph in Atlanta (http://www.gz250bike.com/forum/showthread.php?t=1452)

Raven 09-10-2008 07:42 PM

Re: 71mpg, 75mph in Atlanta
 
I was maxing out at around 65. I adjusted the throttle cable to remove most of the slop and now it can hit 75 mph pretty regular. A tail wind helps.

alanmcorcoran 09-10-2008 08:13 PM

Re: 71mpg, 75mph in Atlanta
 
Raven,

Is it easy for a not-extremely-mechanical newb to tell if he has "slop" in his throttle cable? I'm maxing at 65 as well (or less if there is wind or a grade.)

Do most of you speedsters find you have to downshift to fourth on a 10-12% grade or risk dropping below 40? Seems if I drop down, rev it way up, and then pop back to fifth, I can hold it there, but I haven't done a long enough climb to confirm that.

-Alan.

primal 09-10-2008 09:42 PM

Re: 71mpg, 75mph in Atlanta
 
Quote:

Originally Posted by alanmcorcoran
Do most of you speedsters find you have to downshift to fourth on a 10-12% grade or risk dropping below 40? Seems if I drop down, rev it way up, and then pop back to fifth, I can hold it there, but I haven't done a long enough climb to confirm that.

-Alan.

That's normal. In fact, any uphill grade is tough to maintain in 5th gear unless your going over 50 MPH, and even then you will likely slowly lose speed on the way up. Since I choose fairly uncrowded roads on my way to class I generally just downshift into 4th and cruise around 40 MPH on hills.

Easy Rider 09-10-2008 10:35 PM

Re: 71mpg, 75mph in Atlanta
 
Quote:

Originally Posted by alanmcorcoran
Is it easy for a not-extremely-mechanical newb to tell if he has "slop" in his throttle cable? I'm maxing at 65 as well (or less if there is wind or a grade.)

Probably not. You need to feel the twist grip for movement that does nothing for the engine speed.....then you need to LOOK at the cables where they attach to the carb to see if it looks like there is any excess slack there.
BUT.....
If your bike keeps pulling more the more you twist the grip, up to a point where you can twist it a little more and nothing extra is forthcoming or it actually bogs a bit, then your throttle is probably opening as far as it can and adjustment of the cables won't help anything.

I think your problem is the wind resistance of your massive, manly chest. :biggrin:

Jer 09-10-2008 10:37 PM

Re: 71mpg, 75mph in Atlanta
 
:)

Easy Rider 09-10-2008 10:37 PM

Re: 71mpg, 75mph in Atlanta
 
Quote:

Originally Posted by primal
Quote:

Originally Posted by alanmcorcoran
Do most of you speedsters find you have to downshift to fourth on a 10-12% grade or risk dropping below 40?
-Alan.

That's normal.

Yep. :plus1:

5th_bike 09-10-2008 11:50 PM

Re: 71mpg, 75mph in Atlanta
 
Mine is driven in, just at 3,000 miles, this summer it gave me 74 mpg and max. 75 mph (the needle was a little over, but I wouldn't want to call it 76). No wind shield - flat on the tank. Then, the road went back up.

alanmcorcoran 09-11-2008 02:15 AM

Re: 71mpg, 75mph in Atlanta
 
Quote:

Originally Posted by Easy Rider
I think your problem is the wind resistance of your massive, manly chest.

Yeah, that's what I figured.

Seriously, sometimes I think the brakes are dragging, but I have an overactive imagination. There's a noticeable immediate slowdown when I let off the throttle and it doesn't seem like it is all engine braking. But it's probably my riding position and lack of windshield.

Jer 09-11-2008 08:41 AM

Re: 71mpg, 75mph in Atlanta
 
I get that too. I end up slowing stopping quite short at signs/lights.

I think I'm gonna coast further than I ever do.

Easy Rider 09-11-2008 09:59 AM

Re: 71mpg, 75mph in Atlanta
 
Quote:

Originally Posted by alanmcorcoran
Seriously, sometimes I think the brakes are dragging,

I was going to mention that but then forgot. You SHOULD check them, serioiusly. Before I changed my front sprocket, I was disappointed that the GZ felt like it had almost NO engine braking. Everything is relative, though, and I was coming off an I-4 that had TONS of comperssion braking.

The effect you guys are feeling could also be an indication that your idle speed is a bit too low.

Check the brakes by riding around for a few minutes in an area where you don't need to use either brake (much). Then stop and carefully FEEL the front rotor and rear drum. If either is more than just barely warm, get them checked out.
Overheating brakes can fail suddenly; not good!


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