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Discussion Starter · #1 ·
Hey everyone, I got my daughter an '06 TTR 50. It ran great at first(and still does) but it puffs out a small amount of smoke when she rides it. I've changed the oil and checked the compression(it slowly bumps up to 150 psi after about 5 seconds of turning it over with the electric start). At first I thought it could be old oil so I changed the oil, put fresh gas and it still smoked. I thought it could be the rings but with 150 psi of compression it doesn't seem like that would be the culprit. Any suggestions on what it could be? She rides it every now and then and the last time I checked the oil after she rode it and it was low. Some people say they just ride it with it smoking but I'd rather not lose track of the oil level and blow it up. I've adjusted the valves as well. Could the valves need to be lapped? Or maybe the rings are just bad and it needs new rings? Just trying to get some advice before I order a rebuild kit and just rebuild the top end. It's a great running bike and she loves it so I'm trying to keep it in top shape and not have to worry about it. Thanks in advance and sorry for the long post.
 

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Discussion Starter · #3 ·
Do you know what the compression should be on this bike? I'm assuming 150psi is good, but I couldn't find any info on what the compression should be. I would think if the valve seals were worn the compression would be low but I am not sure if 150psi is low or not.
 

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Administrator "Loose Nut" - from Houston, Texas
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Actually sounds like a fun project, rings, valve seat lapping and valve seals should cover all bases. Stay detailed and clean when working, plus take pictures of ever bolt you touch. Use the pictures for correct reassembly. It's easy to forget what exactly went were and pictures don't lie. I do a of engine rebuilding and document with pictures along the way to confirm all is right. Here's a few of my latest projects.

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Discussion Starter · #7 ·
Very nice, you seem very knowledgeable, I'll keep you in mind for my many other projects I have that always seem to need some kind of work. Luckily I just got done rebuilding a raptor 80 so I have everything for valve lapping and top end rebuild. It's easier to just rebuild it and have a peace of mind knowing you won't have to tear it down again because the $10 seals that weren't replaced were the culprit in the first place. Luckily these small engine parts are cheap and they're easy to work on. Thank you again for your help. I'll keep you updated once I get it torn apart and see exactly what the issue is. I've seen a lost of posts about these ttr 50s smoking but most people seem to just ride them like that instead of fixing the issue.
 

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Discussion Starter · #8 ·
Update on the TTR 50. I replaced the piston rings, cylinder gasket, head gasket and valve seals(the rocker arm shafts were a PITA to get out because it took forever to find somewhere that had an M6x1 bolt long enough to get them out, but I finally found one). Started it, and it still smoke a little. Maybe just residual oil that will hopefully burn off, but still smoking for now. The piston, cylinder and valves looked good(I lapped the valves while I had it apart). I guess we will see with time if it is fixed or not. Any other ideas are greatly appreciated, but I can't think of what else it would be. Thanks again for your help @Lesblank! I also found a video on YouTube by The Dadbod Workshop that was for a TTR 90 but exact same steps for a TTR 50 that helped out a bunch. It's a 3 part video and very detailed. Once again, thank you for your help and ride safe.
 

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Discussion Starter · #11 ·
Just a little update on the ttr 50. My daughter rode it today and I check the oil before she rode it, oil was full. She started it up and it smoked a little, like it did before, but since I just redid the top end I figured it would for a little bit. She rode it for about 20 minutes and when we got home I checked the oil and it was about 1/2 way down the cross marks on the dipstick. It's hard to tell if it's still burning oil because when you hit the throttle it goes away. It didn't seem like it was still smoking after she rode it for a few minutes but where the heck is the oil going? If it's burning that much oil you think you would see it. I don't see oil on the engine either so I don't think it's leaking. I'm lost on this one. Seems like these ttr 50s are a headache for just about everyone that owns one.
 
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