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XR100 / 120 Engine tear down and build up

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My faithful donkey (98 XR100R) is a beautiful example of what happens to a mini bike when it is ridden hard. Real hard.

LibertySteelRims002.jpg

After 18 months of rehab, the suspension is sorted, plastics are cleaned up and a fresh 120 BBK and exhaust is installed.

CanadaDay001.jpg

After a few sessions on the new BBK I found I was getting some sparkles in the engine oil. I barely ran this engine prior to installing the BBK and to be honest kind of threw it together quick as summer was coming to a close.

Time to open it back up, toss in a few goodies and clean up some maintenance issues.

Take001.jpg

Take002.jpg

One of the other forum members has volunteered a manual, so as soon as it arrives, the breakdown will begin.

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Well done...!!!

Looks like a different bike.

Thanks, it mostly is pieces from other bikes: the only unmodified original stock parts left are the kickstand, foot pegs and rear brake lever & pull rod.

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I'm 52 years old, have 13 bikes in the garage from 50cc to 650cc. I think the one I have the most fun on is my 2002 XR100. It brings a smile to my face holding that thing wide open and hanging on. They do wear out quick with abuse like that.

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I'm 52 years old, have 13 bikes in the garage from 50cc to 650cc. I think the one I have the most fun on is my 2002 XR100. It brings a smile to my face holding that thing wide open and hanging on. They do wear out quick with abuse like that.

Heavy crank, heavy flywheel, dump truck low 1st gear, low overall weight and low seat height (most anyway:thumbsup:) make this bike very 'accessible'.

Having spent the majority of my TT time here on the XR80-200 forum I've read lots about dead cam journals due to lack of oil, and experienced it myself on my first bike, a 1980 XR80. Hence the Takegawa oil pump; No, I won't be adding an oil shower valve cover but I'll darn sure keep that galley in the head FULL of oil if I have my way and add an effective oil cooler (with flow restrictor) while maintaining a reasonable amount of oil flow. Why a cooler and not a shower head?

Additional oil capacity. The 'other' project for this winter is to convert to street legal, explaining the 17T counter sprocket and super duty chain guide. I hope to hit and hold 100 Km/H all day long with this bike. Not really enough for an interstate or Hwy, but enough to comfortably run back roads. Should funds hold out... a CB50ss clutch cover with the cartridge type oil filter element. The more oil I can keep in the system, the longer the oil in the crank/cooler will have to cool.

The magnetic oil plug was an extra that Terry @ firepowerminis.com threw in; had I been thinking I would've ordered it anyway as the threads on my factory plug are long since galled. Not to mention cheap insurance on longer rides. Props to our forum member who recently forwarded along a copy of the fsm. Wrenching will begin on Thursday.

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I'm 52 years old, have 13 bikes in the garage from 50cc to 650cc. I think the one I have the most fun on is my 2002 XR100. It brings a smile to my face holding that thing wide open and hanging on. They do wear out quick with abuse like that.

I'm 47, same 'problem'.

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