First timer bike rebuild?

toostroke
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toostroke
Edited Date/Time 5/28/2019 10:00am
I’ve always wanted to rebuild a 125 2 stroke but I don’t have any experience with it or anything. I was thinking about buying a used/ cheap bike from Craigslist and buying a new top end rebuild kit and do some minor adjustments, clean it up, make it look nice, and probably keep or flip it. Should I go for it? Haven’t played with engines at all but I’m willing to learn and got the whole summer break coming up.
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motox331
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motox331 5/21/2019 7:27am
5/21/2019 7:27am
You won't learn unless you try! A 125 is pretty much the easiest bike to learn with as they are very simple mechanically. I say get one and use write ups, youtube and most important the manual for guidance. Happy Wrenching!
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kb228
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kb228 5/21/2019 7:31am
5/21/2019 7:31am
Find a $500 yz125 on facebook and redo the whole thing. The nice thing about the yamahas is theyre so common that theres a video on how to do basically everything on them. Parts are super available too. First bike i did was a 125. Great for a first one
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FWYT
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FWYT 5/21/2019 7:32am
5/21/2019 7:32am Edited Date/Time 5/21/2019 7:47am
Do you have some basic tools and a space to work on it? Yes, do it! Get a manual for it and start watching the various YouTube tutorials on how to do certain things. Keep things organized and clean and TAKE YOUR TIME to do it right.

Careful on buying a cheap fixer-upper as it might need more than just a top end. Those projects have a way of expanding.

Check out all the build threads in the Bike Builds section here on Vital.

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toostroke
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toostroke 5/21/2019 8:25am
5/21/2019 8:25am
FWYT wrote:
Do you have some basic tools and a space to work on it? Yes, do it! Get a manual for it and start watching the various...
Do you have some basic tools and a space to work on it? Yes, do it! Get a manual for it and start watching the various YouTube tutorials on how to do certain things. Keep things organized and clean and TAKE YOUR TIME to do it right.

Careful on buying a cheap fixer-upper as it might need more than just a top end. Those projects have a way of expanding.

Check out all the build threads in the Bike Builds section here on Vital.

I have a open space but barely any tools. I’m a big fan of the bike builds section so that’s where i got the idea from. Is there a way I can tell it only needs a new top end? Because bottom end could be a pain. Thanks!
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toostroke
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toostroke 5/21/2019 8:27am
5/21/2019 8:27am Edited Date/Time 5/21/2019 8:27am
kb228 wrote:
Find a $500 yz125 on facebook and redo the whole thing. The nice thing about the yamahas is theyre so common that theres a video on...
Find a $500 yz125 on facebook and redo the whole thing. The nice thing about the yamahas is theyre so common that theres a video on how to do basically everything on them. Parts are super available too. First bike i did was a 125. Great for a first one
For $500 does it have to be functioning or it doesn’t matter? I don’t want to buy a wheelie boys bike because I’m staying near Philadelphia and they’re all wheelie boys. Much rather buy from someone who rides in the dirt who cares about their bike.
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kb228
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kb228 5/21/2019 8:30am
5/21/2019 8:30am
kb228 wrote:
Find a $500 yz125 on facebook and redo the whole thing. The nice thing about the yamahas is theyre so common that theres a video on...
Find a $500 yz125 on facebook and redo the whole thing. The nice thing about the yamahas is theyre so common that theres a video on how to do basically everything on them. Parts are super available too. First bike i did was a 125. Great for a first one
toostroke wrote:
For $500 does it have to be functioning or it doesn’t matter? I don’t want to buy a wheelie boys bike because I’m staying near Philadelphia...
For $500 does it have to be functioning or it doesn’t matter? I don’t want to buy a wheelie boys bike because I’m staying near Philadelphia and they’re all wheelie boys. Much rather buy from someone who rides in the dirt who cares about their bike.
$500 is usually totally trashed or a blown motor. But the upside is you can make a really dramatic transformation with it.

$1000 is running but probably trashed and on its past leg engine wise.

$2000 is a bike that was cared about and might need a top end or carb clean.

$2500+ usually is a nice bike that doesnt need much work aside some cleaning or tires or something.

Speaking in terms of a 125 2 stroke that is.
smashingpumpkins167 5/21/2019 8:34am
5/21/2019 8:34am
I got a 2002 yz125 for $500 that just needed a carb rebuild. I didn't have a whole lot of mechanical experience and I did everything but the suspension and bottom end. It was fun
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AbouttheRide
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AbouttheRide 5/21/2019 8:51am
5/21/2019 8:51am
Go for it man! Your knowledge, tool inventory, etc. will get bigger and better as you go, don't be discouraged by any of that. Your gonna mess things up, do something wrong blah blah but that is how we have all learned. Ask questions and be open to different answers as you will get a bunch of different ones from dirt bike guys hahaha but above all enjoy it !!!
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FWYT
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FWYT 5/21/2019 9:20am
5/21/2019 9:20am
AbouttheRide wrote:
Go for it man! Your knowledge, tool inventory, etc. will get bigger and better as you go, don't be discouraged by any of that. Your gonna...
Go for it man! Your knowledge, tool inventory, etc. will get bigger and better as you go, don't be discouraged by any of that. Your gonna mess things up, do something wrong blah blah but that is how we have all learned. Ask questions and be open to different answers as you will get a bunch of different ones from dirt bike guys hahaha but above all enjoy it !!!
Agreed. I wish I had done a full bike rebuild a loooooong time ago. Great way to learn.
Blade Flanagan jr. 5/21/2019 1:11pm
5/21/2019 1:11pm
1: Buy a factory service manual, 2: Go to Harbor Freight tools, Lowes or Home depot and buy a socket and wrench set as well as the best torque wrench you can afford (maybe avoid Harbor Freight for the torque wrench). 3: Buy a motion pro flywheel puller and see about renting, borrowing or building a case splitter if you need to do the bottom end. 4: Follow the manual step by step. Don't be intimidated, a 125 2 stroke is very simple to work on. If you have any questions on parts locations when putting it all together you can look up everything on an online microfiche like the ones on Motosport.com or a similar site. 5: Enjoy your like new bike for a fraction of the cost of a new one!
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Kelz87
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Kelz87 5/21/2019 11:46pm
5/21/2019 11:46pm
It gets expensive man Lol I did the same thing with an ‘05 KX125 and I’m kinda over it now. Nothing about it has been as easy as expected, but I’ve learned a lot and can’t say I regret it. My tool collection has also definitely expanded







Be prepared for frustration and ordering parts you didn’t know you’d need. On the flip-side: it’s a great feeling every time you take it out, it’s noticeably a little better
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toostroke
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toostroke 5/22/2019 4:12am
5/22/2019 4:12am
Kelz87 wrote:
It gets expensive man Lol I did the same thing with an ‘05 KX125 and I’m kinda over it now. Nothing about it has been as...
It gets expensive man Lol I did the same thing with an ‘05 KX125 and I’m kinda over it now. Nothing about it has been as easy as expected, but I’ve learned a lot and can’t say I regret it. My tool collection has also definitely expanded







Be prepared for frustration and ordering parts you didn’t know you’d need. On the flip-side: it’s a great feeling every time you take it out, it’s noticeably a little better
That’s what I’m worried about. I don’t want to come across a expensive and difficult to fix problem that a mechanic has to fix. Or need to get rental tools/ machines to open something up that I need to get to
Kelz87
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Kelz87 5/22/2019 7:15pm
5/22/2019 7:15pm
Kelz87 wrote:
It gets expensive man Lol I did the same thing with an ‘05 KX125 and I’m kinda over it now. Nothing about it has been as...
It gets expensive man Lol I did the same thing with an ‘05 KX125 and I’m kinda over it now. Nothing about it has been as easy as expected, but I’ve learned a lot and can’t say I regret it. My tool collection has also definitely expanded







Be prepared for frustration and ordering parts you didn’t know you’d need. On the flip-side: it’s a great feeling every time you take it out, it’s noticeably a little better
toostroke wrote:
That’s what I’m worried about. I don’t want to come across a expensive and difficult to fix problem that a mechanic has to fix. Or need...
That’s what I’m worried about. I don’t want to come across a expensive and difficult to fix problem that a mechanic has to fix. Or need to get rental tools/ machines to open something up that I need to get to
Meh, I don’t mean to discourage man lol if you have the time, money, and maybe an extra bike to ride while the other is down then I’d say go for it. I’m just tired of putting money in mine and finding one bad part leading to another and then needing another part or tool-I just want to ride it now!

Last month I was replacing linkage bearings and found out the swingarm bolt was sheared completely. The month before that I replaced the muffler packing and I’m pretty sure that’ll need to be replaced because the power valve is gummed up and blew oil out the can


toostroke
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toostroke 5/23/2019 7:11am
5/23/2019 7:11am
I can’t find a bike for a good price and you guys scared the crap out of me with the one part needing another part because I don’t have a lot of money to spend or be able to go into really technical stuff
kb228
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kb228 5/23/2019 7:35am
5/23/2019 7:35am
Rebuilding a bike from trash to like new is easily $2000 all in. Thats not counting tools. The initial investment is high if you dont have tools already. But the plus side is once you do it once, youll avoid the mechanic hourly rate for the rest of your life and no more waiting on a tech to get to your bike. Just fix it.
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dickjackson170 5/23/2019 7:41am
5/23/2019 7:41am
toostroke wrote:
I’ve always wanted to rebuild a 125 2 stroke but I don’t have any experience with it or anything. I was thinking about buying a used/...
I’ve always wanted to rebuild a 125 2 stroke but I don’t have any experience with it or anything. I was thinking about buying a used/ cheap bike from Craigslist and buying a new top end rebuild kit and do some minor adjustments, clean it up, make it look nice, and probably keep or flip it. Should I go for it? Haven’t played with engines at all but I’m willing to learn and got the whole summer break coming up.
You should absolutely go for it! I've learned everything I know about working on motorcycles from taking that risk when I was a kid. Take your time, take notes, take pictures and above all, Google what you don't know! It will be a great learning experience. There's nothing to the top end of a 2 stroke.
1
Kennyfreemoney 5/23/2019 7:42am
5/23/2019 7:42am
This was my first rebuild. Maybe not a rebuild since it didn't need engine work, But I paid $1100 for the bike, put on tires, new fork seals, new air filter, Grips, levers, chain (sprockets were good), chain guide, bar pad, case saver, 2017 Front fender and number plate, and graphics. Cleaned up the pipe and heat colored the welds. In it for a total of $1,695. Could've done a top end for another $150. The only tools I bought were fork seal driver and fork tube bullet.


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toostroke
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toostroke 5/23/2019 8:25am
5/23/2019 8:25am
Kennyfreemoney wrote:
This was my first rebuild. Maybe not a rebuild since it didn't need engine work, But I paid $1100 for the bike, put on tires, new...
This was my first rebuild. Maybe not a rebuild since it didn't need engine work, But I paid $1100 for the bike, put on tires, new fork seals, new air filter, Grips, levers, chain (sprockets were good), chain guide, bar pad, case saver, 2017 Front fender and number plate, and graphics. Cleaned up the pipe and heat colored the welds. In it for a total of $1,695. Could've done a top end for another $150. The only tools I bought were fork seal driver and fork tube bullet.


Sick bike, I can’t find any that cheap they’re like 2k or 1.5k over here. Guess I’m going to have to lowball someone which I hate or wait for it.

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Kennyfreemoney 5/23/2019 9:43am
5/23/2019 9:43am
Kennyfreemoney wrote:
This was my first rebuild. Maybe not a rebuild since it didn't need engine work, But I paid $1100 for the bike, put on tires, new...
This was my first rebuild. Maybe not a rebuild since it didn't need engine work, But I paid $1100 for the bike, put on tires, new fork seals, new air filter, Grips, levers, chain (sprockets were good), chain guide, bar pad, case saver, 2017 Front fender and number plate, and graphics. Cleaned up the pipe and heat colored the welds. In it for a total of $1,695. Could've done a top end for another $150. The only tools I bought were fork seal driver and fork tube bullet.


toostroke wrote:
Sick bike, I can’t find any that cheap they’re like 2k or 1.5k over here. Guess I’m going to have to lowball someone which I hate...
Sick bike, I can’t find any that cheap they’re like 2k or 1.5k over here. Guess I’m going to have to lowball someone which I hate or wait for it.
Ya this guy had it listed for $2200. Talked him down to $1,500, went and looked at it and got him down another $150 because of fork seals. Then he ended up sending me back another $250 because he didn't have a title. So I ended paying half of what it was listed for
Zesiger 112
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Zesiger 112 5/23/2019 9:56am
5/23/2019 9:56am Edited Date/Time 5/23/2019 9:57am
Do it. Learn now while your young save a lot of money in the future not having to pay someone. My advice would be to pay a little more at the start for a good bike to avoid the posibility of expensive problem with a cheap bike. take it apart and replace only what is needed. You'll see a lot of builds where they immediately replace every bearing on the bike. That's not always necessary. Get it safe and rideable first then make it nice. If you try to rebuild it and trick it out it all at the same time it will sit in the garage forever.

As for cost, look in for sale section here, eBay, and only buy trick parts on holidays like Black Friday.
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FWYT
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FWYT 5/24/2019 1:06pm
5/24/2019 1:06pm Edited Date/Time 5/24/2019 1:27pm
Zesiger 112 wrote:
Do it. Learn now while your young save a lot of money in the future not having to pay someone. My advice would be to pay...
Do it. Learn now while your young save a lot of money in the future not having to pay someone. My advice would be to pay a little more at the start for a good bike to avoid the posibility of expensive problem with a cheap bike. take it apart and replace only what is needed. You'll see a lot of builds where they immediately replace every bearing on the bike. That's not always necessary. Get it safe and rideable first then make it nice. If you try to rebuild it and trick it out it all at the same time it will sit in the garage forever.

As for cost, look in for sale section here, eBay, and only buy trick parts on holidays like Black Friday.
I agree with this. Please don't be scared off by the potential issues. Yes, they will probably come up but that is part of the fun- figuring things out! Maybe set your time frame for more than just this summer. Take your time to shop for a good project bike. In the meantime, watch a bunch of DIY vids on how to do easier things like wheel and linkage bearings. Start collecting tools. (Including a good heat gun! That was one of my more valuable lessons recently is that heat is an excellent tool!)

I can't tell you how much I wish I would have learned how to do a full bike back when. (And it is so much easier these days with all the online help!) Keep things clean, organized and take your time. I used to be such a fucking hack and my work got so much better when I slowed way down and stopped rushing through things. Do it, man!
DoctorJD
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DoctorJD 5/24/2019 1:11pm
5/24/2019 1:11pm
When it comes to the technical side of the build...YouTube is your friend.
dickjackson170 5/24/2019 1:17pm
5/24/2019 1:17pm
toostroke wrote:
I can’t find a bike for a good price and you guys scared the crap out of me with the one part needing another part because...
I can’t find a bike for a good price and you guys scared the crap out of me with the one part needing another part because I don’t have a lot of money to spend or be able to go into really technical stuff
Stop it. Replacing things you didn't expect is part of any project. Just relax and wait until you find a deal. The majority of the parts aren't crazy money. There's not a ton of specialty tools either. It's a couple here and there. You will have to accept it's going to take longer than you thought too. You can still find bikes that need work for a grand or less. Forks can be rebuilt relatively cheap, all new plastic is a little over 100, tires are whatever you want to spend, gasket kit.... The rest isn't all that much. You'll gain a lifetime of knowledge. Don't let random dudes on the internet talk you out of it.
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TbonesPop 5/24/2019 1:21pm
5/24/2019 1:21pm
toostroke wrote:
I’ve always wanted to rebuild a 125 2 stroke but I don’t have any experience with it or anything. I was thinking about buying a used/...
I’ve always wanted to rebuild a 125 2 stroke but I don’t have any experience with it or anything. I was thinking about buying a used/ cheap bike from Craigslist and buying a new top end rebuild kit and do some minor adjustments, clean it up, make it look nice, and probably keep or flip it. Should I go for it? Haven’t played with engines at all but I’m willing to learn and got the whole summer break coming up.
I say go for it. Get your tools from Harbor Freight. Most of the time, the quality on basic tools is perfectly fine for most. Would i get their tools if my livelihood depended on it? No. For hobbies? Absolutely! You will save 50-80% over buying anywhere else. Having a good torque wrench is something I would advocate spending more money on though. You can do a lot of $$ damage if you don't torque properly. 125 2 strokes are super easy to work on, so don't think it will be difficult - it's not. Do plan on spending more than you originally think you will though. Once you get into the project, you will always want to upgrade or replace parts that need it. But that's not just for rebuilds, thats part of owning any off road toy that goes fast and/or jumps things in the dirt. Stuff breaks. You fix it, ride it, break it, repeat. Enjoy the process along the way.
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KBOLTZ
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KBOLTZ 5/24/2019 1:52pm
5/24/2019 1:52pm
I blew the motor on a 97 kx250 when I was 16 and never got it fixed cause i couldn’t afford labor for mechanic and I was afraid of doing on my own for not knowing about the bottom end. Speed up time and I’m 34 yrs old, last year piston skirt blew my 04 yz250 and dropped in the cases. I was nervous but said fuck it. I committed and took my time. I took the initial money hit for the tools and got to work. It was challenging but overall way easier than I thought. 16+ hours on the bike now and going strong. Just got back from Caineville and it ran great. Sounds like OP has those stresses too. You can do it man.
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mattyhamz2 5/24/2019 3:31pm
5/24/2019 3:31pm
Anytime I buy a used bike, I plan to rip the entire motor apart and rebuild it all. Insurance.

Unless the guy has proof that everything was replaced recently and with OEM parts, I always plan for an entire rebuild.
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toostroke
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toostroke 5/26/2019 7:17pm
5/26/2019 7:17pm Edited Date/Time 5/26/2019 7:19pm
Just realized as a 17 year old my parents aren’t too hot with the idea especially with 0 experience. Probably gonna have to save some more cash up so I don’t have to borrow some money because it’s more of a gamble with 0 experience and a tight budget.

I do appreciate the comments and tips though!
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chuck356
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chuck356 5/27/2019 7:13pm
5/27/2019 7:13pm
As a dealer for almost 40 years, I have always encouraged my customers to do as much work to their bikes as they can. And I have never had an issue with tech support as long as they were willing to listen to me. Youtube is a 50/50 deal, some of the advice is good, some not good, so be careful. Buy the parts, buy the tools, take your time, and enjoy the feeling of doing it yourself.
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Nuffsaid
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Nuffsaid 5/28/2019 8:13am
5/28/2019 8:13am Edited Date/Time 5/28/2019 8:37am
Research a particular bike you want, just don’t purchase a bike because of the price. Pay whatever price for the bike you’ve narrowed down to “the one” you desire. Even if a owner states they have “renovated “ it I still tear it down to the frame and do it myself. In the long run that will be a plus because you know what is in your bike and preventative maintenance will be less expensive then something unknown failing and disastrous outcome.Enjoy
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WW444
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WW444 5/28/2019 10:00am
5/28/2019 10:00am
I lucked up and found my 04 that I got from a kid for $800. It was a little rough but overall decent and ran. I blew it up first ride so I put top end in it and I have slowly been building on it since. I do not know the amount I have in it but its always more than you plan. But I have loved doing this with this bike. Good luck buddy!
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