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smoking xr 100

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I was just given an xr 100 that has been used and abused. Im an old 2 stroke motocross guy but am pretty clueless onthe 4 strokes. I cleaned the carb and air filter,changed the oil and fired it right up. It will sit right there an idle but smokes like crazy. The (new) oil is milky colored. It runs and shifts o.k. just smokes real bad. Where should I start ? Thank you.

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start with the piston rings and oil scraper, but since its used alot the engine could be totally worn.

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start with the piston rings and oil scraper, but since its used alot the engine could be totally worn.

Would you suggest taking the engine out or just start by taking the cylinder off and changing the piston and rings. Ive changed a ton of 2 stroke pistonsbut this is going to be totally different. What will i see when I take the cylinder off. Whats the 'scraper'. Will I have to mess with timing, valves etc. to change the piston and rings ? Thanks.

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honestly, it's not that bad. This is about the simplest 4-stroke engine you could ever encounter. I was pretty freaked out when I needed to do some engine work on my XR100. I ended up taking it to a mechanic buddy of mine. He walked me through the whole process as he did it and once I got over the "OMG I am lost" stage, it all was pretty straightforward.

Pick up a service manual (check e-bay) and you'll be able to figure it out. If you've done top ends on 2-strokes, you obviously have mechanical ability. Don't let the whole 2-stroke vs 4-stroke worry you. Just follow the directions in the manual and you'll be fine.

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honestly, it's not that bad. This is about the simplest 4-stroke engine you could ever encounter. I was pretty freaked out when I needed to do some engine work on my XR100. I ended up taking it to a mechanic buddy of mine. He walked me through the whole process as he did it and once I got over the "OMG I am lost" stage, it all was pretty straightforward.

Pick up a service manual (check e-bay) and you'll be able to figure it out. If you've done top ends on 2-strokes, you obviously have mechanical ability. Don't let the whole 2-stroke vs 4-stroke worry you. Just follow the directions in the manual and you'll be fine.

another stupid question....im reallyt not that tight with the local dealer, wheres the best place on here to buy oem and aftermarket honda parts. thanks. so it sounds like i need a piston and some rings ??!?!

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Hold off on buying any parts until you get it apart and check if the cylinder is worn beyond spec, chances are the cylinder will need reboring too if it's smoking that bad. Although it is certainly possible that the previous owner just over heated it and a set of rings will fix it right up.

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Agreed. Don't buy parts till you know what you have to work with. Pull it apart, get the service manual and check stuff over first. Then buy parts.

There's multiple places online that you can buy OEM parts from. I usually get mine from RonAyers.com, but even this site has the ability to get OEM parts from it. Just look around. The microfiche is your friend!

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I got some parts from my local dealer, some from cheapcycleparts.com and some from ebay. I got a piston and rings from ebay for pretty cheap. For my other smoker, I got a whole new oversized piston, rings, cam, cylinder, and gaskets to turn it into a 132cc for $229 off ebay.

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yeah, often you'll find that if the top end needs to be redone, it might be cheaper to just go the big bore kit route as they tend to include everything to redo the top end.

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Here is a trick a old school flat tracker taught me years ago, he told me to get a hotter sparkplug for the bike. it will help burn the oil off before it can escape the cylinder and look like a chimney. Now it will not stop losing oil but will make it run better for a while if you don't have the cash to do the top end.

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