Is 5th gear useless to anyone else?

[tommygun]

I have a 2008 gz250. I like the bike but live in NE georgia and have a huge problem getting up some of the hills. On flat ground I even have trouble maintaining 55-60. I use high tess fuel and have a maintinace plan with the bike. I have put 6300 miles on the bike since July. Is this a general issue with the bike or is it just me?

[Easy Rider]

Is this a general issue with the bike or is it just me?

Welcome!

Yes and yes! :)

A few things come to mind:

No need to use "premium" gas. Your bike might run better with regular.

Part of the problem is the equipment and part is technique.

How big a person are you? Do you have a windshield? You might want to do a search here for "windshield". One that is not TOO big can actually help lessen the wind drag.......which is the main problem with top-end speed.

The technique part is getting the most you can out of 4th gear before you shift to 5th. Top speed in 4th is about 55-60 mph (help me out here "stock" riders). If you know you are approaching a hill or are in a stiff head wind, it's important to get the most you can out of 4th. The more speed you can (safely) carry into the hill the better. Sometimes you can't use 5th at all.......if the hill is steep or LONG or the head-wind is REALLY strong.

Tell us a bit more about the situations you have encountered and we can go on from there.

[tommygun]

I am 175 and have a small spitfire shield. I didn't know about the regular gas, that should save some money! I hear all these pople saying how they have had thiere bikes on the interstate, there is no way my bike will get up to 70- 75 unless I am going down hill!

when approching a hill I do just as you said. I can only maintain 55 un a hill when in 4th gear. I have noticed more of a problem with top speed in the colder weather. I ride no matter what and have more of a problem in the morning

[Easy Rider]

I am 175 and have a small spitfire shield. I didn't know about the regular gas, that should save some money!

How small is the shield? Does it really keep the wind off your chest AND head ??
Ducking down to minimize your wind exposure might help some.....as would hooking your heels on the passenger pegs. Both those things cut down the wind drag.

I think your experience is fairly typical. Your definition of "hill" and mine are probably somewhat different. :)

As far as the gas goes, you might want to read the owner's manual when you have a few minutes to spare !! :whistle: :biggrin:

[tommygun]

My route to work has alot of "quick hills" (much like an interstate over pass) and some gradual hills. Is there any way go get more power out of this little bike? i.e. special plugs, sprockets, or slapping a turbo on the sucker? any tips? my shield is 15 x 17. it is just right for the bike and helps me riding comfort just right. I am looking for some affordable hand deflectors for my winter riding. Also what is everyone averaging on MPG?

[alanmcorcoran]

tommy,

I am in a hilly area as well and I generally have dropped 5th from consideration unless the road is flat. On a positive note, I can get the bike up to 60 in 4th without difficulty. I have a pretty big windshield. Before the windshield, I had to put my face down on the speedo to get the last 10 mph out of the bike, but I think I was able to go 3-4 mph faster at the top end.

I do not have the 16T mod which apparently improves the low end power bands but adversely affects the top end.

You will hear plenty otherwise from other riders here, several of which are competent "modders", but in my opinion, you can forget about cruising at 70-75 on the interstate. I've hit 70+ on the bike, in 5th, on a flattish paved road (probably with the wind on my back) but it's an ideal condition thing. I do think you can count on 63-65ish or so most of the time.

Mine is a 2008 too (about 2400 miles) and did get a little faster over time. Not dramatically so though. I completely agree with Easy - get the all the revs you can out of 4th. After the first couple thousand miles, I changed my shifting habits to use a lot more of the upper range of the gears.

At the end of the day, the GZ can be used on the interstate, but it's not the best use of the bike. This bike shines around town and on the backroads.

[tommygun]

"I do not have the 16T mod which apparently improves the low end power bands but adversely affects the top end."

I have though about the "16t" but couldn't figure what "top end" was. As of right not I can squeeze 60-65 would it be cut down to 50-55 w/ a 16t? does anyone know?

[Easy Rider]

My route to work has alot of "quick hills" (much like an interstate over pass) and some gradual hills. Is there any way go get more power out of this little bike?

No. Assuming that you are the first owner and it is still bone stock, you should not be having as much trouble as you seem to be describing.

It will NOT pull a hill in 5th at less than 55 mph; it just won't, meaning it won't maintain speed. Even at 60, you will probably lose a few MPH. If you can attack the hill at 65 (or more) you should pull it just fine, with minimal loss of speed.

Try a couple of tanks of regular gas. Consider using synthetic motorcycle oil. Other than that, just down shift when needed.......and stay off roads where you NEED to maintain a speed faster than 55 to stay alive. :cry:

The "average" fuel mileage seems to be around 65-70.

[Easy Rider]

I have though about the "16t" but couldn't figure what "top end" was. As of right not I can squeeze 60-65 would it be cut down to 50-55 w/ a 16t? does anyone know?

"Top end" power is what you are complaining about.

I have the 16T sprocket and it cut my top end speed down from about 75 to 70 and it takes a LOT longer to get up to that speed.

It would appear that you are NOT a good candidate for a 16T front sprocket.

[tommygun]

See now I would be thrilled to get up to 70! I have been 70mph down hill only?! does the 16t give you more torque? to maintain a top speed of 60-65?

[CMS]

I'm in Southen Ohio and we do have hills. My 08 will touch 70 [no windshild ,flat land ] I recently took my first extended ride to the South. On Rt 68 South from the Dayton area to Riply Oh. [believe it or not] I maintained 60 /63 on most of the trip ,on the hills, I did lose speed [5th gear] but I only downshifted once to 4th. This was on one long climb and I down shifted about half way up the incline, on the others I increased my speed at the bottom of the hill as much as possible. This helped on the smaller and shorter climbs, although I would still lose some speed. I'm 170 and the bike had Cortech side and top bags installed. Over all I'm still pleased with the speed of th GZ, it is a 250 and there are limitations, but I really enjoy my trips more so than on my larger bike.The larger bikes are for getting from point A to point B, my 250 is more of an adventure trip, it allows me to see the sights, but I digress. :rawk: CMS

[Easy Rider]

See now I would be thrilled to get up to 70! I have been 70mph down hill only?! does the 16t give you more torque? to maintain a top speed of 60-65?

No, quite the opposite, less torque. Like I said, it would NOT be a good thing for YOU.

And another thought or two:

1) It takes a LONG time to achieve top speed with an underpowered vehicle like the GZ. If you crank it up to 55 or so in 4th, it might take you another 1/2 mile OR MORE to achieve 70 in 5th.......on the flat with no head-wind. Honestly. If you don't have that long a straight, flat road (or not enough patience) you will come to BELIEVE it won't do 70.

2) If you are in 5th going about 60 and start up a hill, don't assume that just because it slows down a little bit that it will KEEP getting slower and slower. It probably won't. It might drop 5-7 mph on a slight hill and then keep going at 50-55 in 5th just fine. IOW, don't panic and don't downshift to 4th until it drops to 50 or less (or it's obvious that it is a BIG hill).

3) Don't be afraid to open the throttle all the way. Most of the time, that is the only way you can maintain speed in 5th gear.......really.


It REALLY sounds to me like you just need to resign yourself to what the GZ really IS: A small, underpowered motorcycle. If you can't live with that, then you got the wrong bike. :cry:

[alanmcorcoran]

Tommy,

Other posts I've read on here indicate that you won't redline in 4th until you hit 70 or so, which, you've apparently never hit. Next time you're on a hill, try winding the thing out as much as you can in 4th. (If it's a steep hill, forget it, third is your only option there.) Also, several of us have noticed an anomaly where the bike actually goes a little faster with the throttle backed off a tad from wide open.

If your bike won't go over 60 on a flat road, something is probably wrong. I have no mods, a windshield and I weigh 175ish. I'm a fairly inexpereinced rider, but I can get it up to 60 on the flats pretty easily. 65 is usually doable as well, depending on the road and the wind. Above that, I need smooth asphalt, a tailwind, and a little luck.

Experiment with a different oil. Also, make sure your oil isn't low. A lot of people seem to be happy with the Rotella T 5w40 synthetic. It is sold for diesel engines, but it seems to work okay for the GZ.

Finally, don't discount the value of a warm-up. My bike doesn't really hit its stride until it's been running for about 15 minutes.

[trykemike]

Hey Tommygun search the howto section re: power increase.

Also I have been thinking that the owners who have trouble reaching 65 + may have a carburetor with a 115 main jet so the engine is starving for fuel. Check the owners manual re: carburetor specs .

I am 5 ' 6 "" 165 lbs . I can always top 75+ mph and have reached 80 + a dozen times this pas summer. I never down shift on a hill and maintain 50-65 mph depending on conditions and hill steepness and length.

Try a slight bit of choke about 1/8 in cold weather it works for me . I reached 130 kph when the temp was 40F with a little choke.

When I pulled the plug it was a little black on the tip but gold the rest of the way.

[theneanderthal]

Yeah, as mentioned, I'd have to question whether the motor is sufficiently warmed up.

Have you hit 1000 miles on the odo? If not the thing isn't broken in yet and isn't capable of producing max power until it is. Have you done a valve adjustment yet?

My geezer didn't really hit its stride until I exceeded 1k, did a valve adjustment, and the little scoot was warmed up. I generally ride for 1/2 or more before the mouse motor really starts to produce the power its capable of.

Mine isn't happy on regular 87 octane gas despite what the manual says but 89 makes it smile.

I bought mine with 8 miles, used, and no owners manual so it got broken in hard, mostly at full throttle, contrary to the manual suggestions. Also it seems there are no two of these things alike as far as performance is concerned so ymmv.

[Water Warrior 2]

The GZ is a smaller bike with limitations. Not a lot can be done to improve the performance but some things help. Always make sure tire pressure is correct. Low PSI means more rolling resistance. On Lyndas bike the pressure is kept at 2 up specs which also helps a bit with tire wear. Synthetic oil might help a bit but do not expect to notice anything drastic. Good oil will just normally make the bike smoother to operate. Have you done a valve adjust yet. Might help a little too. Basically just ride and accept the bike for what it is and enjoy what it is capable of doing. In the future you may want to upgrade to something more powerful and hand the bike to another newbie looking for a smaller bike.

[alantf]

87 & 89 octane petrol? I wish that we could get it over here (Tenerife). It must be cheaper than the 95 or 98 octane, which is the only lead free that they sell here.

[Easy Rider]

87 & 89 octane petrol? I wish that we could get it over here (Tenerife). It must be cheaper than the 95 or 98 octane, which is the only lead free that they sell here.

Same stuff; different measurement system. :biggrin:

North America usually has 3 octane choices and Europe only 2.
Don't know for sure which one is missing on your side of the pond but I think it is the middle one.

[tommygun]

Thanks Gang, I purchased the bike with the intent to ride it into the ground. I have put about 6500miles on it in 4 months so I hope it will last riding it wide open all the time. Whats the going distance before a complete engine overhaul?

[Rick]

You might try changing your spark plug and running some Berryman's B-12 or similar fuel system cleaner through the bike. I did both of those things recently when my GZ was acting a little sluggish, and now it's running great. I can easily get up to 75-80 on flat road, and it'll accelerate on moderate uphills even in 5th. I'm pretty light though (145) so I'm sure that helps some.

[Easy Rider]

Whats the going distance before a complete engine overhaul?

Depends on what you mean by "riding it wide open".

Wide open in 5th is quite different than wide open in the other gears.

We've had a couple of guys on here that liked to red-line it in all the gears, all the time and they lasted less than 30,000 miles.

OTOH, there are quite a few approaching 50K miles and still going strong but I suspect that they never have it wound out all the way.......because it won't do that in 5th !!

[GZ250]

if you want speed, go for a 650cc or up. GZ250 isn't made for that. may be there are some individual bikes that can go faster or some mods help. i cannot go beyong 65mph. this is the maximum i can go in any situation but bike runs great.

need for speed, upgrade.

[Badbob]

5th gear is over drive.

I went on a trip a few months back. About 1800 miles half or more of this on mountain roads loaded with my 220 lbs and all me camping gear and tools. The only problem I experienced was with me not reading the road ahead correctly and being in the proper gear. This improved dramatically as the miles went by. On this trip I used 5th gear primarily in the flat country going to and from the mountains. I don't usually shift into 5th gear unless I'm going at least 50 mph.

There is nothing wrong with down shifting. To go up a mountain.

[alanmcorcoran]

I agree Bob. As my time on the bike increases, I have gradually raised the rpms in all the gears and I reserve fifth now mainly for freeways and 50+ mph. On moderate inclines I have held the bike at 60 mph in fourth gear.

I used to race to get into 5th and was typically in it by 40 mph.

In the beginning I retained my old car shifting habits (formed during the first gas crisis (77-79) where the name of the game was low rpm, high gas mileage. This may work when you have a 100-150 horsepower car, but if you want decent speed out of the GZ, higher rpms are better. I went through a similar learning curve on the bicycle - high cadence gives you the most power (and is also best for the "engine") there as well.

Now that I am used to it, I'm enjoying the thing a lot more, and I'm doing a lot better on the freeway.

[Badbob]

Now that I am used to it, I'm enjoying the thing a lot more, and I'm doing a lot better on the freeway.

I also found that I enjoyed the ride much more when I let the GZ be what it is and ride in the middle of the power band or at least what feels like the middle to me. I looked for some info on this once and was never able to find any. I would loke to see a graph of HP or torque vs rpm for this engine.

[NoMates]

I agree mine seems to love to rev so I let it do just that. Once I got over the fear of blowing it up I found my highway speeds increased and its happy buzzing away. I wouldnt say 5th gear is useless its just not as useful as 4th..

[Chris]

Hi Tommygun
Are you still looking at this post? I also ride in north Georgia and have no problems on the interstate. Let me know.

Chris, Cobb County

[mr. softie]

See now I would be thrilled to get up to 70! I have been 70mph down hill only?! does the 16t give you more torque? to maintain a top speed of 60-65?

The 16t gives you a higher final drive gear, so less torque for a given speed. However it does allow you to take 4th up to higher speed. I stay in 4th up to 65-70 on hills if I need to, with the 16t. With the 15t I would only get to 65 tops in 4th. I really don't have trouble maintaining 70mph on the highway at all in 5th, once I get there. I use 5th as an "overdrive" gear. Not much torque or power in fifth whatever sprocket you run. It is like riding a bicycle in a way. The trick with the gz is keeping the rpm's up when accelerating or hill climbing, and dropping them down when you are just maintaining a speed. Sometimes a nitrous kit would be handy. hmmm... maybe a roller cam? BTW I am using the SpitFire windshield as well . :2tup:

Don't be afraid to wind this engine out if you need to. A ninja 250 would be slow too if you never took it over 5000rpm. While the GZ does have nice usable power at the lower rpm's, it makes it's best power and torque at higher rpm's. Top torque is 18.7 Nm @ 7,000 rpm and top hp is 20.1 hp @ 8,000 rpm. The redline is about 8700 rpm and top speed is around 75mph. I have gotten mine up to 87mph! (tail wind, drafting a semi, downhill, hot day, feet on rear pegs, chin on bars) and I weigh 220lbs.

See my recent post on valve adjustment for power tips. Might be worth trying a valve adjustment to tweak a tiny bit more horsepower. I don't think changing exhaust and intake etc. is worth the trouble and expense for the small power boost you might get but you can adjust the valves for free. You can also try turning your mixture screw out a tad and raising the carb needle to get a bit more pep. Plus make sure your tires are aired up and your brakes aren't dragging. I have heard running Rotella or Castrol 10-40 synthetic oil can also give you a bit more get up and go. I am using the Rotella. Every little bit helps with the GZ.
http://www.gz250bike.com/forum/viewtopic.php?f=10&t=2113&p=18790#p18790