Motor rebuild- total work time

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1/23/2019 12:02 PM

How long does it take you to take apart a two stroke motor, put in new main bearings, crank (you have a freshy already waiting) and piston, and button everything back up? Motor is already out of the bike and on the bench. Using only hand tools. Normal pace, not trying to rush the job.

Note I said new piston. That's because the circlips alone are a 45 minute job for me. laughing laughing laughing

Add your time for a four stroke motor, if you like.


1/23/2019 12:24 PM

I done my first one and it took me like a week. But I kept running into little things like getting the right flywheel puller, getting the cases resurfaced, and the first time you put a transmission back in it is nerve wrecking. I would def have somebody else there to help you hold everything so you don’t drop it and you look down and have a billion washers and gears everywhere that you have NO IDEA where it goes. Do you have a flywheel puller that can get yours off? If not? Get one. Do you have something to resurface the cases? I live 10 min from a guy who mods bikes and he just rubbed the inside of the cases that press together on a perfectly flat surface and “smoothed” them out so it will seal correctly. Like $20 and it took him 2 seconds. But you might can DIY it. Never looked it up. Always took it to him. Do you have a clean work space? If not. Clean a 5x5 place out. If you have all this and sit down and get it done you can do it in probably 5ish hours. I have done another one and I forgot a little piece after I had it all back together and I tore it back down and back together in like 30 min. But I didn’t have to take the transmission out or mess with the crank bearings. It’s really not that hard. Just take your time and don’t try and rush anything.


1/23/2019 12:56 PM

Taking your time and doing things right 4.5 to 5 hours sounds right in my garage.


1/23/2019 1:31 PM
Edited Date/Time: 1/23/2019 1:32 PM

If the cases, cylinder head, etc. Are all 100% prepped ready to go everything clean and checked all you need to do is assemble it probably 3 hours or less. Prepping everything and checking it all before assembly is what takes time.


1/23/2019 1:36 PM

If you have the tools and new parts, 2h maximum. Workshop should do it in way below 2h. First time maybe 3-4h because you dont know when to use a bit more force and you want to triple check everything.

Tools needed to be effective and not run risk of causing damage:

- Case splitter,
- Fly wheel remover,
- Clutch basket locking tool,
- Bearing remover.


1/23/2019 2:00 PM

I was just looking at this yesterday:
It's definitely worth it for a regular joe by the time he has to buy tools, manual, mess it up, pull it back down again, break a few things along the way, strip a bolt.


KTM250SX YZ125 YZ85 PW80 ZX6 FZX700

1/23/2019 4:02 PM

3-4 hours on a motor. 10 hours to do the entire bike. Hardly ever happens in one chunk. Usually goes strip down, tear motor down, inspect parts, vapor blast, order parts.. so on and so fourth.


1/23/2019 6:22 PM

8 hours cuz your gonna look at every little part and tripple check to make sure everything is right.


1/24/2019 12:54 AM

Will never know, cause the parts waiting game sux balls!
And also I seem to be getting shitter the older I get with circlips.


1/24/2019 4:38 PM

If one of the minis I am used to doing and everything is ready and in good shape? 2 hours or less. That said, usually something needs special attention that takes up some time. PV cleaned, etc.......


1/26/2019 9:56 AM

It takes what it takes to do it right the first time. THat can be 1 hour or many hours.

Paw Paw