'06 GZ freeway driving problems

[cfsmith]

Hey guys,

First post, want to indtroduce myself but at work and have to type quickly :roll: I'll get to the intro at lunch!

A quick question for those of you mechanically inclined... recently bought an '06 gz250 as my first bike, lovin' it (~1,100 miles in 2 weeks!!), but have noticed a bit of an issue the last couple of times I commuted on the freeway. Y'see, I can cruise on this bike at 55 all day long, and get about 65 mph on freeway commutes, but twice this week I've noticed that, instead of the normal performance I get (between 60-65 mph, no noticable slowdowns), after a few minutes on the superslab I'll find myself slowing way down on any sort of incline (to about 52 mph) and then it crawls back up to about 58 mph at full throttle.

Once I exit the freeway my acceleration is waaaay down, it doesn't seem to have the normal 'oomph'. It just takes a while to accelerate again in 5th gear.

I let it sit all day while at work, jump back on, and it's back to normal!

Anyone have any inkling of what this may be?

Charlie

[JWR]

They all lose speed up hill.

Down shift to 4th gear and wind it up.

Let us know what the results are.

I believe a windshield will give you more top speed. Plus is is much easier on your body.

[Moedad]

Since you just got it and have put 1,100 miles on it in two weeks, do you have any idea when the last time it had fresh oil in it was? Maybe your oil is old and cruddy and is making your motor work too hard..

[cfsmith]

@JWR, it didn't seem to lose as much speed a week ago, but maybe I'm 're-breaking' it in or somesuch. I'm definitely interested in a windshield. Just gotta find one

@Moedad, I had the bike serviced prior to riding it as it had sat for about 6 months with the rare back-and-forth in the driveway according to the previous owner. So, at least the oil is clean. I'll be checking fuel filter and spark plug this week-end.


Maybe I haven't experienced the bike long enough, but from some of the posts here about 70 to 80+ mph, I was a little surprised at the perceived under-performance of my machine.
-c

[Moedad]

Originally Posted by cfsmith

Maybe I haven't experienced the bike long enough, but from some of the posts here about 70 to 80+ mph, I was a little surprised at the perceived under-performance of my machine.

The difference in power thing is somewhat odd, but as far as not being able to go 70-80 mph, that's not surprising. Anything--head wind, inclines, low tire pressure--will start to affect the GZ's speed right away when you're above 60. The little bike just isn't made for that stuff. It'll do it, yeah, but not well for very long. If somebody spends a lot of time going 75 mph, they are most likely going to need a motor rebuild in a couple of years unless they are maintenance fanatics and even that might not be enough. Treat them right and these little bikes are bullet-proof, but they will knuckle under to abuse sooner or later, depending on the degree of abuse.

[alanmcorcoran]

Most of us ain't getting 80 so don't feel like that's likely. In my case, it takes a bit of coaxing to get it up over 70. Realistically, I'm pretty happy with 65 on the freeway. (I have a windshield.) With no windshield on, if you stick your chin on the speedo, you can get another 10mph.

BTW, it'll go 60-65 in fourth. You'll need it uphill or into wind.

I'm thinking maybe your mixture is too rich? It works okay when it's cold, but then when you are good and warmed up it's too rich. But i don't really know much about engines.

I would also say it might be a little psychological. Wait until you get a bigger bike and then go back on the GZ. It's not built for acceleration.

[cfsmith]

Honestly I'm happy, very happy, with a consistent 65. I've never had it past 70 mph and even that single instance was by accident O.o

I was just worried about some sort of sign of engine trouble as it **seemed** to be fine on week 1, then 'problems' popped up on week 2. It could just be a perception thing, not sure.

Is 60-65 mph considered abuse on the gz250??

Alan, no idea on the mixture - I'll be checking when I know more. In any case it's up for its 6000 mile checkup, I'll be taking it in next week when it turns. You may be right about the acceleration, but I could've sworn it was better last week - or, at least not as weak. e.g. heading up the Arkansas River bridge last week I noticed no slowdown, 60 mph all the way up (not a steep bridge, just a clean, steady incline); this week, I sink quickly to 52 mph.

I'll be checking into some things this weekend, and maybe in the end I'll find out that it's just me .

-c

[alantf]

A lot of people (me included) have found that carb cleaner in the tank works magic. If, as you say, it's been standing for a while, then there may be some shite in the carb. Check the posts for which is the best carb cleaner. As I'm not in America, I can't pass an opinion on different types as we get different stuff over here.

[alanmcorcoran]

Try the suggestions (4th gear, higher rpms.) You have to get used to having the bike really wound up at high speeds - that's its happy place. I don't think there is an official book on what's considered abuse, but I think the majority of readers on here ride 60-65 regularly. There was one guy who rode his WTFO all the time and i think his piston eventually blew up, some of it is probably more due to how you GET to the 65 rather than the 65 itself.

A clean steady incline, plus a little headwind, *will* take you out of 5th gear and into the 50's (or even lower!). Learn to only use 5th on flats or downhill.

I think your bike is bahaving normally. You just are getting used to the freeway speed and it seems a little poky when you go back to the surface streets. Don't expect much in the way of acceleration out of the GZ. It's more of a slow and steady bike. You can make it a little zippier if you wind it out a little more before you shift, but, really, it's best to just let it be what it is. If/Once you get the big bike fever, you'll be getting something a LOT quicker if that's what you want.

Meanwhile, enjoy the lightweight, low operating costs and the gas mileage.

[cfsmith]

Thanks for all of the advice, I'll be checking it all out this weekend. The carb tank cleaner (?) sounds like an idea - in any case, I think I'll be learning a lot over the next couple of weeks on how to keep this bike clean and maintained.

Also, I don't want to give the opinion that I'm not pleased with the bike; au contraire, I've really enjoyed it! I've circled through counties around my own, around the hills, over the rivers, through the woods, put miles to grandma's house, etc. I'm lovin' it, no worry cruisin'. First bike and all mine.

I just perceived a potential problem that I'm learning may not have been an issue with the bike, but rather with myself. Plus, trying to get to work on a Monday morning and you ain't worried about the view but rather that 8 am shift change!



I'll give a riding report after I've taken a look at some of what you've suggested and tried to clean 'er up a bit.

Thanks and good riding this weekend

-c