GZ 250 Forums - View Single Post

kilo0195 · 01-22-2018, 08:25 PM

That's ultimately what I wanted to achieve... was a cheap bike that could be made to handle more on the cheap. Around here you can pick these bikes up for $1000 and they can modified pretty cheap. I wanted to try and accomplish what others said was impossible for this bike, and show that it can be done for little money. With the 300cc kit itself I was able to easily run a 16t front and 39t rear sprocket and have plenty of torque for 70-75mph and could easily hit 80-82mph for passing. It could peg the needle at 88 but was a little slower climb past 80. This makes the bike very capable for highway speeds and reliability at those speeds. The other mods are probably more than most people's cup of tea but turns the bike into something that can easily keep pace with most 650 and 750cc cruisers. The cam I'm hoping will bring some more torque to the mid and top end to help with passing especially if I have an extra 100lbs or so of rider on the back. The sprockets I'll keep the same as 4th gear now is basically what the stock 5th gear used to be. It allows me to use 5th as basically an overdrive for the highway. The bike is most alive in 3rd and 4th and in those gears feels like I've got twice the motor under me. If anybody has questions I'm more than happy to answer or help if they're interested in building theirs up. The big thing to note for internal parts wise is that the 91-95 Suzuki dr250 is essentially the same size for many parts. The heads are different, the dr250 has more oil journals than the gz that won't match up to your jug. Otherwise it would be nice because half the porting work is already done. Inside the Head though all the rockers, springs, retainers, bearing washer etc etc are same size specs. For these parts there are plenty of aftermarket beefier items you can buy. Unfortunately the bottom end is completely different. The bottom end internals seem to be holding up fine so I don't think anyone needs to worry about rods and the like. That's also with me pushing the bike harder than the average person would. So if 300cc is all someone is wanting to do then I'd suggest that along with Kevlar clutch plates, 16t and 39t sprockets, and the obvious rejetting. One should be able to get all of that for under $300.

01-22-2018, 08:25 PM	#26
kilo0195 Member Join Date: Jul 2017 Location: Illinois Posts: 52	That's ultimately what I wanted to achieve... was a cheap bike that could be made to handle more on the cheap. Around here you can pick these bikes up for $1000 and they can modified pretty cheap. I wanted to try and accomplish what others said was impossible for this bike, and show that it can be done for little money. With the 300cc kit itself I was able to easily run a 16t front and 39t rear sprocket and have plenty of torque for 70-75mph and could easily hit 80-82mph for passing. It could peg the needle at 88 but was a little slower climb past 80. This makes the bike very capable for highway speeds and reliability at those speeds. The other mods are probably more than most people's cup of tea but turns the bike into something that can easily keep pace with most 650 and 750cc cruisers. The cam I'm hoping will bring some more torque to the mid and top end to help with passing especially if I have an extra 100lbs or so of rider on the back. The sprockets I'll keep the same as 4th gear now is basically what the stock 5th gear used to be. It allows me to use 5th as basically an overdrive for the highway. The bike is most alive in 3rd and 4th and in those gears feels like I've got twice the motor under me. If anybody has questions I'm more than happy to answer or help if they're interested in building theirs up. The big thing to note for internal parts wise is that the 91-95 Suzuki dr250 is essentially the same size for many parts. The heads are different, the dr250 has more oil journals than the gz that won't match up to your jug. Otherwise it would be nice because half the porting work is already done. Inside the Head though all the rockers, springs, retainers, bearing washer etc etc are same size specs. For these parts there are plenty of aftermarket beefier items you can buy. Unfortunately the bottom end is completely different. The bottom end internals seem to be holding up fine so I don't think anyone needs to worry about rods and the like. That's also with me pushing the bike harder than the average person would. So if 300cc is all someone is wanting to do then I'd suggest that along with Kevlar clutch plates, 16t and 39t sprockets, and the obvious rejetting. One should be able to get all of that for under $300.
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