power problem

[Andreas40]

Hellos guys
I just bought a 2002 GZ250 , when I test it in parking lot and seemed ok, however now I have a power problem… first , second . and even third gear seemed ok accelerate ok and the engine seems to have enough power and I can reach up to 40mph , after that in forth and fifth gear the bike has no power it remains to 40mph or even go down… it seems like there is no power after third gear , it seems to me like no more gas flow but it confuse me the fact that until third gear is ok , is it any adjustment in curb for high speed? If yes where I can find it ? is that something I can do by myself ?
It also seems like timing problem, does this bike have timing adjustment ? how I can find it ? the bike have only 4500miles … did anybody have similar problem ? I will appreciated any advice and suggestions

Thanks

Andreas

[jonathan180iq]

Since you purchased the bike used, there is a possibility that it was not properly maintained.

Considering your problem, I would suggest that you look at two things:

1: Has the air intake system ever been tampered with?
If so, it may be that the carb simply needs to be adjusted.

2: Like you said, you can check the valves.
If you do not feel comfortable with pretty technical work, I would suggest you take the bike into a repair shop and have them work the problem out.

There is always a risk when buying used. However, due to the simplicity of this bike, there just isn't TOO much that can go wrong.

If my 2 suggestions don't work, check everything off from this list:
If they don't solve your problem, at least you'll know that all of the parts mentioned will be in good working order.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~
Install a new spark plug

Check the plug wire for problems

adjust throttle linkage

Clean the carb

Empty the tank and try some new gasoline

Make sure that your chain is properly adjusted

Wash the bike (just the sake of doing so)

I doubt that you have any type of internal problem (ie: the transmission) because a problem like that would cause significant grinding and banging in the other gears.

Good Luck
Jonathan

[Easy Rider]

Originally Posted by jonathan180iq

Since you purchased the bike used, there is a possibility that it was not properly maintained.

Considering your problem, I would suggest that you look at two things:

1: Has the air intake system ever been tampered with?
If so, it may be that the carb simply needs to be adjusted.

Clean the carb

Empty the tank and try some new gasoline

Good advise.

Modifications to the air intake system without corresponding exhaust
and carb changes can have a DRASTIC effect on performance (more on that soon).
If that has been done, it probably would be better (IE quicker and easier) to put it back to stock.

Not finding any other obvious reason for the problem, I would certainly put in fresh gas with carb cleaner.

Oh, and no, the timing is not adjustable (electronically set) but I suppose it could be off if something is broken.

It might be well worth it to have a shop go over it. That should get you back on the road sooner than just tinkering around looking for the problem.

Good luck!

[jonathan180iq]

Hey, Easy, you're just 3 posts away from having the distinction of ULTRA MEMBER!!!!!

WooHoo! :roll:

[Easy Rider]

Originally Posted by jonathan180iq

Hey, Easy, you're just 3 posts away from having the distinction of ULTRA MEMBER!!!!!

I'm ULTRA excited..........not really! :cool:
Now only 2.