Powering up my GN250 (stop laughing)

[motnick]

I'm about to try and power up my GN250. It only needs a smidgen more power so that 5th gear can keep me at 100kms/hr

First thing I'm gonna try is a 14 tooth front sprocket (factory is 15). Gonna mean more gear changing in town but whatever.

If that doesn't work, I'll consider the 13 tooth thats available, but I reckon that will be too much and i'll run out of revs.

I'll also try and go the other way if I can, go bigger and forget about 5th gear. At the moment 100km/hr is red lining in 4th, might be able to bring that down a notch.

But I'm wondering if anybody has done these things already? What can you recommend?

Can I just change fuel to 96 or 98 octane? If so do I need to adjust anything? Will it screw the engine? Will it even make a difference?

Only asking cause I'll be getting a bigger bike next year as soon as i get my full license and i don't want to throw much money at it, but I need a little bit more power now, 90kms/hr is frustrating at times.

thanks in advance.

[Toaster]

I guess they canned it based on profitability, or lack of.

I don't know what the national or international sales were like, but it seemed like a good starter bike or a nice budget bike and suitable for smaller riders.

[koba]

Rip the head off and shave it lots :D
Then the 98 wont be wasted.

[xwhatsit]

Yes, indeed, as Koba says, 98/96 octane will be wasted. Unless you do as he suggests, and raise the compression ratio (by shaving the head, or fitting a high-comp piston).

It's a 2006, what kind of condition is it in? Often some basic maintenance, such as cleaning/replacing the air filter with a new one can boost performance.

Put some low bars on it. Then you can get your head down a bit more. When I sit upright, I can only manage 135kph or so; if I get my head down over the tank, the speedo slowly starts climbing again. More uncomfortable though.

I wouldn't do the fourth-gear thing, you might as well use all the ratios you have so you can accelerate up to 100kph faster. There are several gearing calculators on the net, might be worth fiddling around before you drop money on a sprocket set.

I reckon changing that rear tyre to a normal profile one would help too. It's really fat, and square -- a lot of rubber touching the road there. Skinnier tyre == less rolling resistance.

[HTFU]

Forget i said anything about a gpx, you too tall.

[fireball]

how did you know i was laughing?

cheap option get a fxr or rg something similar... they may be small bikes and put out 2 less hp than the gn but you can get them up to over 120 comfortably and maintain that speed on hills in wind

[motnick]

It's a 2006, what kind of condition is it in? Often some basic maintenance, such as cleaning/replacing the air filter with a new one can boost performance.



It's in good condition, just clicked over 4000k's and has been fully serviced 500k's ago.

It doesn't help that I'm 110kg's and 6'1".

Most of the time I am in town, but i still have some out-of-town trips for work.

I won't be getting another 250, I bought this one because it will loose me the least money before I trade up in 138 days (and counting).

I'll try the 14 tooth front sprocket first, only $20 and a bit of time. I'll let you all know.

thanks.

[NighthawkNZ]

find a cheap GN 400... motor should swap

[FROSTY]

Holey cow---dude forget it if that lil bike doed 90 ish with your weight bow down and thank the biker gods.
Seriously dude--Try changing the BACK sprocket so the bike sits at 100km/ at about 7000rpm

[HTFU]

find a cheap GN 400... motor should swap

Sounds like a fun way to spend some time playing in the shed but not that practical, finding one of the few that landed here would be the first hurdle.

Yeah a 43-44 spocket on the back may be better than changing the front. Keeping 5th around 7000-7500 rpm at 100 km/hr may be the ticket.

6'1" - get a hyosung GT, Its a big bike, and second hand around 4000-5000. If you are a relatively new rider a keeper for a few years getting skills on. Only $2000-2500 to upgrade. I was on my full and still went for a 250 because of the economics of it all (nothing cheap except old high-milage secondhand bikes) and my relative riding experience (I am a confident rider but still, only 1 years experience). If you are an experienced then the world is your oyster in 4 months.

[Paul in NZ]

Frankly I love the notion of hotting up a GN and plan to do the same in the future...

The downside of this is - if you screw it up the investment in the GN will be wasted - tolerate the lower power for the time remaining and the patience you will develop will be a HUGE asset to you later...

[Kickaha]

Frankly I love the notion of hotting up a GN and plan to do the same in the future...



My GN125 went from 7rwhp to 13.5rwhp now lets see you get that big a percentage increase in HP for under $400 out of any other bike :lol:

[R6_kid]

maybe look for a bigger carb? or less carbs and some exercise? :Pokey:

[Brett]

Not to rain on your parade...but bang for buck unless you can do the work yourself, you will pay lots of good cash for work that will not make a helluva lot of difference. Either upgrade bikes or suck it up till ya get your full! Good luck!

[Mom]

I guess they canned it based on profitability, or lack of.

I don't know what the national or international sales were like, but it seemed like a good starter bike or a nice budget bike and suitable for smaller riders.

I sold these bikes when they were first released in NZ back in the early '80's, they were not expensive compared to other like machines, not cheap either, good value bike. I still see one of the first ones I sold in '83/4? around town being used as a commuter.

That aside, Suzuki made the decision to get these bikes manfactured elsewhere, at a cheap price, and they got a cheap bike as a result. The modern GN is not a patch finish-wise on the originals, rusty in months for example.

I think it more likely that reputation is suffering from all the complaints/warranty claims and the like. They will have made good money on them in the first instance. Be sad to see the GN leave the lineup again, as I still think it is a great learner bike/commuter.

[Toaster]

I sold these bikes when they were first released in NZ back in the early '80's

To the tune of Abba no doubt.... I remember when they were cool the first time... or was that the 70's? I forget.....

[rwh]

Put some low bars on it. Then you can get your head down a bit more. When I sit upright, I can only manage 135kph or so; if I get my head down over the tank, the speedo slowly starts climbing again. More uncomfortable though.


I think MikeyG said he turned his bars upside-down - so they're below the clamps, rather than above. Nice and cheap :) Mind you, he may have only done that for track days, and left half the switchgear off; I guess the switchgear should still fit.

Richard

[Wheeliemonsta]

Loose some weight - it's the most cost effective mod you can do...

Cheers

:rockon: