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Installing 125 parts in my DR100

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Got an 85 DR100 that I'm trying to get a little more power from. I hear I can stick the DR/DR-Z125 piston and jug on for an easy upgrade, but I can't seem to find anyone that's actually done it. Do I need the head? Any changes required in carburation or exhaust? I've also found LT125, ALT125, and GN125 parts, are they the same? LT230 cam is supposed to be the hot cam too, can't seem to find a cheap one though. Any help, parts lists, etc would be greatly appreciated, thanks.

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I did an LT 185 top end on my DR100 cases. I had to clean the cases up a bit to fit the spigot in (casting flaws), but otherwise it bolted right up. LT 185 cylinders are getting rare, but stock size pistons are available from Suzuki still (apparently - I got rings 3 days after ordering them). Bore out a evilbay 125 cyl and install the 185 piston and rings. ALT, DR, DR-Z, GN and LT125 parts are the same for the top end, save the cam.

For a 125 or 143 piston (same price almost) you should change the head. LT 185 piston, no need, it has a small dome. Exhaust is fine, but you can ditch it for a stock DR-Z exhaust to save weight, carb needs rejetting, but the early DR125s have a 22mm that works better.

When we get it back, check a thread titled Interesting mods to my 125L. It has measurements galore!

All DR-Z 125 top end parts WILL bolt up. That includes the EO 190 kit.

Did you ever get your brakes working right?

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Got the brakes kinda working, but they seem to be fading again, must be an issue with the drum/hub since I put new shoes and a new cable.

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If I can't find a 22mm 125 carb, how should I jet the stocker for the time being? I'm at 5K feet, the GF rides the DR up to 10K, so I don't know if the exhaust and carb would even help.

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Try a 22.5 pilot, 105 main and a TTR125 needle in the middle position.

The exhaust is more about losing tonnage, but a bigger carb will help with your girlfriend's revving.

Funny thing is, mine did the same today on my 155cc DR125. I had bought a DR100 motor as a spare to hot rod for her bike (for my own amusement) and she's revving the piss out of it trying to rail our tiny berm!

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Those numbers should work pretty well at 5000-10000 feet you think? Where would I find a TTR needle, can I get a stock part from bike bandit?

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Those are from sea level to 5000 ft, stock numbers from my neighbors All Original 1982 DR125

Needle is the stock TTR one, yes.

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I dunno anything about Yamahas, what year TTR needle should I be looking for? I found a DR125 Carb, would I still need the needle for that, or would the stocker do?

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