What should I have my mechanic look at?

[1999GZ250]

I got my GZ about 9 months ago and planned on riding it a lot but my friend knocked it over and bent the bars. After that I decided to do a full bobber conversion. My question is this: All I have done to the motor is rebuilt the Carb and added a new spark plug. What else should I have my mechanic look into? Someone mentioned valves. Anything else? I have only put about 5 miles on the bike myself and want to put lots more miles on it without worry. Thanks.

Also, will a GN250 Big bore kit work on my GZ250? http://www.ebay.com/itm/182195462390
Says its compatible but can't be sure.

[Water Warrior 2]

Definitely have the valves checked by a trusted mechanic. Properly adjust valves will make the bike start and run better. Also replace the front brake fluid as it may be original and contaminated over time.
Also check the brake pads and shoes. Adjust all cables and lube them for ease of operation. Use contact cleaner on all switch gear to improve contact.
How old are the tires? Any tire over 5 years should be replaced. Rubber gets hard and slippery with age and just might bite you when you least expect it.
Check the chain and sprockets for wear too.
Check all the lights for function. The list goes on but this will get you started. A little TLC will make the bike happier and more reliable.

[wacio]

Replace oil and check air cleaner. Let oil out of air box. Checking for loose fasteners is good idea too.

Also the big bore kit is just a waste of time. This bike is never going to be fast - and not intended to. It may become much less reliable though. One of the weak points of GZ250 is head - seizing valve stems and dropping seats are common already - and may get much worse if pushed hard.

Keep it below 60mph and it will last. Going past that is something this engine hates.

[1999GZ250]

I had new tires installed, new chain, a valve job done and the brakes checked. Thanks for the help! Now onto exhaust, carb, intake etc!

[1999GZ250]

Originally Posted by wacio

Replace oil and check air cleaner. Let oil out of air box. Checking for loose fasteners is good idea too.

Also the big bore kit is just a waste of time. This bike is never going to be fast - and not intended to. It may become much less reliable though. One of the weak points of GZ250 is head - seizing valve stems and dropping seats are common already - and may get much worse if pushed hard.

Keep it below 60mph and it will last. Going past that is something this engine hates.

Noted thanks.

[1999GZ250]

Originally Posted by Water Warrior 2

Definitely have the valves checked by a trusted mechanic. Properly adjust valves will make the bike start and run better. Also replace the front brake fluid as it may be original and contaminated over time.
Also check the brake pads and shoes. Adjust all cables and lube them for ease of operation. Use contact cleaner on all switch gear to improve contact.
How old are the tires? Any tire over 5 years should be replaced. Rubber gets hard and slippery with age and just might bite you when you least expect it.
Check the chain and sprockets for wear too.
Check all the lights for function. The list goes on but this will get you started. A little TLC will make the bike happier and more reliable.

Question: I cannot find the definitive answer on which main jet to get for the carb. Some say the Mikuni large size 130-145 and others say the small size. So whch is it? Also do I need anything to shim my needle besides thin brass washers? Some pics show a notched needle with a clip and some show a white plastic looking washer. Thanks again


Here is what I believe is the correct main jet: http://www.ebay.com/itm/Genuine-Miku...FXv3sn&vxp=mtr

[1999GZ250]

Originally Posted by wacio

Replace oil and check air cleaner. Let oil out of air box. Checking for loose fasteners is good idea too.

Also the big bore kit is just a waste of time. This bike is never going to be fast - and not intended to. It may become much less reliable though. One of the weak points of GZ250 is head - seizing valve stems and dropping seats are common already - and may get much worse if pushed hard.

Keep it below 60mph and it will last. Going past that is something this engine hates.

Question: I cannot find the definitive answer on which main jet to get for the carb. Some say the Mikuni large size 130-145 and others say the small size. So whch is it? Also do I need anything to shim my needle besides thin brass washers? Some pics show a notched needle with a clip and some show a white plastic looking washer. Thanks again


Here is what I believe is the correct main jet: http://www.ebay.com/itm/Genuine-Miku...FXv3sn&vxp=mtr