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Nightsbane
08-25-2011, 05:16 PM
If you don't have a tach, how do you know if you are?

I am currently commuting this fall to class about 25 min away. I am not wanting to damage the bike. I know height, weight, hills, wind affect speed, but how do I know if I am running it too hard? Just trying to be careful. There is one stretch for five miles where it's low traffic and still only two lane, but 65mph. I'm 6ft, 200 pounds.
blaine
08-25-2011, 05:31 PM
In 5th gear,at 50 MPH you are reving about 5000 RPM,at 60 MPH about 6000 RPM, and 70 MPH about 7000 RPM.
:) :cool:
5th_bike
08-25-2011, 11:48 PM
...And in 4th gear, you can get up to 65 (stock 15 tooth front sprocket) at 8000 rpm, but I wouldn't do it for long.

The official redline is 9,000 rpm as far as I know.
Nightsbane
08-26-2011, 06:01 AM
The odd thing is that since I went out driving tonight the sound of the ngine has changed (in town) in went from its normal throaty sound, to a much lighter, quieter, and tinny sound and I can't figure out why. I was pretty low on gas and I have just put some B-12 Carb Cleaner into the last tank run through, other than that I am hoping I haven't done something.

On RPM terms, there have been a couple times I have been in 5th gear and full throttle, only at a top of 70 mph, but in the wind sometimes it take giving it all she's got to maintain speed and get over some light hills.

Thanks for info so far, any other info would be appreciated, just trying to protect the bike.
Nightsbane
08-26-2011, 06:22 AM
I wanted to add that outside the wind as a resistant, the roads are 99% totally flat. Right now my main concern is the sudden change in engine sound. It is much cooler outside tonight as well for the first time in two months. Just trying to figure out if I have a problem or if I broke something with highway driving...
alantf
08-26-2011, 07:01 AM
I've just bought a new helmet. Same as my old one, but a much snugger fit, because the lining hasn't had time to squash up. The engine sounds MUCH different. Like a different bike, in fact. :)
Nightsbane
08-26-2011, 07:47 AM
I'm talking about my engine sound without a a helmet on, has changed dramatically to a lighter, tinny, and less powerful sound though I notice no power loss.
blaine
08-26-2011, 08:47 AM
The odd thing is that since I went out driving tonight the sound of the ngine has changed (in town) in went from its normal throaty sound, to a much lighter, quieter, and tinny sound and I can't figure out why. I was pretty low on gas and I have just put some B-12 Carb Cleaner into the last tank run through, other than that I am hoping I haven't done something.

On RPM terms, there have been a couple times I have been in 5th gear and full throttle, only at a top of 70 mph, but in the wind sometimes it take giving it all she's got to maintain speed and get over some light hills.

You will not damage the engine going 70 in 5th gear for short bursts.The B-12 probably loosened up some carbon in the combustion chamber,causing the bike to sound different.
:) :cool:
jonathan180iq
08-26-2011, 09:00 AM
Bikes do change sound overtime.
I'll agree with Blaine, here. A good hot run on the interstate, coupled with a tank of carb cleaner and some age on the bike probably broke off some specs of carbon. The engine is probably running like it should now. These things were never known to be throaty speed demons ;)

And for what it's worth, the 70mph into a headwind part is just about as fast as you're going to be going. If you spend much time on the interstate, I would recommend a 16T sprocket change, simply to keep engine revs down a bit. The change is easy enough. If you see a time when you won't be commuting as much, drop back to the 15 if you want. I just kept it in there.
jonathan180iq
08-26-2011, 09:03 AM
Some handy reading for you:

Speed for Gears - viewtopic.php?f=4&t=4675&hilit=speed+chart (http://www.gz250bike.com/forum/viewtopic.php?f=4&t=4675&hilit=speed+chart)

16T sprocket "How-to" - viewtopic.php?f=8&t=317 (http://www.gz250bike.com/forum/viewtopic.php?f=8&t=317)
Water Warrior 2
08-26-2011, 12:55 PM
I wanted to add that outside the wind as a resistant, the roads are 99% totally flat. Right now my main concern is the sudden change in engine sound. It is much cooler outside tonight as well for the first time in two months. Just trying to figure out if I have a problem or if I broke something with highway driving...
I think you have the answer in front of you. Much cooler air will make a difference because it is denser air. You have denser air going into the engine and you are hearing with denser air around your ears.
jonathan180iq
08-26-2011, 01:12 PM
I think you have the answer in front of you. Much cooler air will make a difference because it is denser air. You have denser air going into the engine and you are hearing with denser air around your ears.

This is true too.

I had a custom muffler on my other scooter. (lawn mower muffler)... Anyway, long story short, it sounded awesome during the morning commute to work and sounded like a lawn mower muffler on the way home from work in the heat of the afternoon.

Go figure.
Nightsbane
08-26-2011, 03:12 PM
Thanks guys. My commute to school take a total of 25 minutes, and only ten minutes is at 65, the rest at 55-60. Is that an acceptable amount per day for the bike?

Thanks for the great info jonathan, where do I order a sproket like that?
jonathan180iq
08-26-2011, 04:07 PM
This bike can handle 65MPH all day every day.

And keep reading in those other threads, my friend. All of your questions are already answered.
Nightsbane
08-27-2011, 07:00 AM
Read some more, only problem is that sproket is out of stock on the site provided :/
blaine
08-27-2011, 08:26 AM
Read some more, only problem is that sproket is out of stock on the site provided :/
Any dealer should be able to order you the sprocket.The Suzuki part#:27511-37200.
:) :cool:
Nightsbane
08-30-2011, 08:08 PM
According the the site provided, it says this is the one I need, is this the right one?
blaine
08-30-2011, 10:38 PM
According the the site provided, it says this is the one I need, is this the right one?
Yep,right one. :) :cool:
Nightsbane
08-31-2011, 01:39 AM
Did I forget to post the link or did it get deleted?
blaine
08-31-2011, 08:49 AM
Did I forget to post the link or did it get deleted?
You must have forgot.I thought you were talking about one of the links back at the first of the thread.Post it again.
:) :cool:
jonathan180iq
08-31-2011, 10:50 AM
Did I forget to post the link or did it get deleted?

Never saw a link there and it doesn't show up in the edits history.

You can find them anywhere. You are not limited to a certain store:

Where can I purchase a new sprocket?

The Suzuki factory part number for a 16T sprocket is 27511-37200
The JT Sprockets part number is JTF 434.16

Sprocket Specialists make both front and rear sprockets for the GZ250.
The front sprockets are available from size 10-16. Part number: 528-(number of teeth)
The rear sprockets are available from size 28-74. Part number: 461-(number of teeth)
Nightsbane
08-31-2011, 07:18 PM
This is the one I meant to link, just want to verify it before I buy it:

http://www.bikebandit.com/jt-sprockets- ... et?b=37041 (http://www.bikebandit.com/jt-sprockets-steel-sprocket?b=37041)
jonathan180iq
09-01-2011, 09:04 AM
There isn't enough info on the link to tell if that is specifically for the GZ. Looks like a generic JT Sprockets ad. I don't even see where to input your bike's information.

EDIT: Looking around more, it does specify that BikeBandit PART: 37041 is the 16T sprocket for the GZ. I don't know why they wouldn' also list the manufacturer part number.

Anyway, that's it. Buy it! :)