questiions from a n00b..

[short stop]

So, I'm new to motorcycling. Not entirely new to 2-wheels - I rode a moped back while in college. But I'm new to gear shifting, and I've started riding my 2000 GZ250 about a month ago. I've ridden it around the neighbourhoods and have gotten fairly comfortable with upshifting and downshifting, stop signs, right+left turns, traffic, all the fun basics, etc.

But I have some questions about the shifting in terms of speed and performance of the bike. I've heard time and time again that the bike can reach highway speeds (albeit with some effort). The other night while coming home from work I decided to try the highway (no cars on road at 3am), and gave the bike all it had, and couldn't get it to go any faster than 90kmh (apologies, Canadian here). Keep in mind, I weigh about 115lbs. I was also trying my best to upshift as late as possible (I think I was, anyways). So...I guess my main question is whether this is caused by:

1) n00bie shifting
2) this is a 250cc, duh
3) mechanical issue with bike

Any suggestions would be appreciated. I do plan on trying the highway again in the near future, and am willing to try anything to get it to go a bit faster.

[Sarris]

The GZ will normally do 65 to 70 mph no problem, so if you are only getting up to 56 mph (90 kph) you may need;
A) A tuneup and spark plug
B) A valve adjustment
C) A new air filter

Realize also, that 5th gear on the GZ's a basically an overdrive, so rev the crap out of it in 4th to get close to your needed speed before shifting into 5th.

Hope this helps. Anybody else with a thought or two??

:2tup:

[Easy Rider]

Hope this helps. Anybody else with a thought or two??


I think that about covers it. :tup:

With an 8 year old bike and a rider who, apparently, isn't too mechanically inclined, I suggest a visit to the shop is in order.

Wild Idea: There ARE 5 gears. 90 kph would be about tops in 4th.

[bigwonton]

Can you actually get up to 90 KPH on the Don Valley Parkinglot? :lol:

I would also suggest trying to keep it in 4th as long as you can before you upshift into 5th.

I'm a bigger guy than you were and only managed between 100-105 KPH on the highway with my GZ250.

[5th_bike]

Two thoughts:
D) you were going slightly uphill.
E) You kept sitting straight up.

To reach speeds over 65 miles, it is handy to go downhill, or at least be on a flat road (ab-so-lu-te-ly not uphill) and lay flat on the tank, to minimize air resistance. If you go uphill in 5th gear, depending on the incline, it may not even get up to 60 mph... which is about 95 kmh.

[Easy Rider]

Only one thought:
D) you were going slightly uphill.

It IS easy for us who know that to forget what a large factor it can be.
A head wind will do it too.

[short stop]

Two thoughts:
D) you were going slightly uphill.
E) You kept sitting straight up.

To reach speeds over 65 miles, it is handy to go downhill, or at least be on a flat road (ab-so-lu-te-ly not uphill) and lay flat on the tank, to minimize air resistance. If you go uphill in 5th gear, depending on the incline, it may not even get up to 60 mph... which is about 95 kmh.

I *was* on a slight uphill incline. I will definitely try another on-ramp and see how the bike performs, and let you guys know!

Also, I'm also pretty new to how the bike should feel in terms certain gears. If I'm in 3rd gear, as I'm approaching 60kmh the bike stars to feel "jerky", or like there's not continuous power to the engine. Buzzy and "sketchy". So...um....do you think this is because I need to upshift, or because of potential problem with bike?

[philbert]

I am only able to "top out" at around 63 MPH, granted this was on a windy day but I don't see how I can get it much faster since I had the throttle pegged. I'll try getting more out of her on a calmer day, making certain I'm on a flat section of road.

Also, when shifting I generally follow the shift points suggested in the owner's manual; 20, 30, 40, & 60 KPH (easier to see than the corresponding MPH) and at these points it sounds as though the bike is really wound up. I only have 1400 miles on the bike, it's out of the break-in so maybe I'm being too timid about this.
Any suggestions to get more performance out of her would be appreciated.

[patrick_777]

...at these points it sounds as though the bike is really wound up....I'm being too timid about this.

The bike will sound like it's about to explode at around 70mph, but you will definitely be the one to fail first. Also, just off wide open is usually better than full lock on the throttle. Mine actually slugs a bit on power if the throttle is WFO, because it's actually flooding the engine. Even at highway speeds, it doesn't take well to a full throttle in 5th.

...of course, each of these bikes is pretty unique. Mine runs proud at 70, and has cleared 80 in perfect conditions (slight downhill, slight tailwind, full tuck). But throw in any variable like headwind, incline, traffic, poor body position or flappy jeans, and I can watch the top end drop to below 65 in 5th.

[Orpheus]

I am only able to "top out" at around 63 MPH, granted this was on a windy day but I don't see how I can get it much faster since I had the throttle pegged. I'll try getting more out of her on a calmer day, making certain I'm on a flat section of road.

Also, when shifting I generally follow the shift points suggested in the owner's manual; 20, 30, 40, & 60 KPH (easier to see than the corresponding MPH) and at these points it sounds as though the bike is really wound up. I only have 1400 miles on the bike, it's out of the break-in so maybe I'm being too timid about this.
Any suggestions to get more performance out of her would be appreciated.

When I'm winding the gears out under perfect conditions, I usually shift into 5th gear around 55-60 MPH (around 90-95 KPH), so there's probably quite a bit more you can get out of it before shifting into 5th. Your shift into 4th also seems way too early; I'm usually not into 4th until around 40-45 MPH (around 65 KPH). There's another thread around here somewhere with the shifting discussion on it; search around and you'll probably find it--it's actually a pretty recent thread, so it shouldn't be too hard to find.

The suggestion about a tune-up is also a really good idea if you haven't done it yet.

[jonathan180iq]

I'll second the opinion that WOT is less ideal than say, 90% throttle. I get a high top speed (~70mph) at 90%. WOT limits me to 65mph or so.

The only way to get more juice out of this bike is to follow Jaime's thread on rejetting the carb. He claims speeds around 87mph. I think that is probably the fastest top speed of anyone else on the site.

You can tweak a few things here or there, but they won't get much faster, even with a good bit of work. I gave up on all of the carb work becasue, honestly, the return simply wasn't worth the headache of doing the work.

[philbert]

I found out why I was having trouble topping out at more than 60ish. The other day when leaving work I noticed a brake fluid drip on my "dash board." Thinking it was from a loose banjo fitting at the reservoir I stopped at the Suzuki dealer near work only to discover that there was more to it. I bought this bike as a demo bike which was used in a training program. After the bike was dropped in class the dealer I bought it from (not the one mentioned earlier) had replaced the brake lever with an after market lever. Even though this lever was said to work on the GZ250 the pivot pin hole was drilled slightly off and consequently the brake reservoir piston was held slightly closed causing the leak and the front brake to drag.
$97 later the front brake pads and the lever are replaced and I now can ride much faster, although I've not brought myself to go any faster than 65MPH. There was a lot of throttle left so I'm sure the bike will go faster I just have to bring myself to do it.
I hope I can trust aftermarket parts for the bike in the future but I will be cautious.