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-   Onroad Nitro Engine Zone (https://www.rctech.net/forum/onroad-nitro-engine-zone-71/)
-   -   Engine rebuild guide? Cant find one... (https://www.rctech.net/forum/onroad-nitro-engine-zone/893906-engine-rebuild-guide-cant-find-one.html)

Marko R1 09-26-2015 08:00 PM
Engine rebuild guide? Cant find one...
 
Hi guys

I want to pull down my engine (21 IDM and OS) and was wondering if there was a step by step guide/reference I can use? I have a general ideas thanks to a mate of mine...I just want to be thorough.

Thanks

danyvw 09-26-2015 09:25 PM
Originally Posted by Marko R1 (Post 14199358)
Hi guys

I want to pull down my engine (21 IDM and OS) and was wondering if there was a step by step guide/reference I can use? I have a general ideas thanks to a mate of mine...I just want to be thorough.

Thanks
Just search YouTube, there are no less than 15 videos of how to rebuild a nitro engine.

blis 09-26-2015 10:25 PM
  1. Remove the clutch and leave the flywheel on (You'll need it to remove the liner)
  2. Remove Air cleaner, wash in soapy water and leave to dry
  3. Remove the pullstart if applicable
  4. Clean the engine - including head bolts
  5. WARM UP THE ENGINE with a hair drier so it's hot to touch, not scolding.
  6. Loosen the glow plug
  7. Check the carby is tight, if you want to service the carby, remove it and be mindful of o-rings
  8. Remove the back plate
  9. Remove the head, if separate head, try to turn the flywheel to pop the button.
  10. If you have to pry, pry equally, opposing each one forming a star and use a plastic blade!
  11. Grab a cable tie small enough to fit through exhaust port. Position the head of the cable tie in the cylinder so a small portion of the cable tie is lined up with teh liner and the rest with the piston.
  12. Turn the flywheel, if the liner is free, then it should lift as the piston gently pushes upward. NOTE: I said gently, if the liner is stuck, this isnt going to work.
  13. If the liner is stuck, then I'd add more heat and try again, if that fails, then I take piston up to TDC and pry the liner upwards with a plastic screwdriver of types using the crank for leverage... If that fails, you may have to put the engine block in the over (minus carby) and hope 120c-150c helps
  14. Once you have the liner out, remove the piston by using thumb and index finger at TDC.
  15. Remove the flywheel, if you dont have a puller, put an old clutch screw back into the crank as far as you can go and give the screw a tap with a rigid metal object and it should pop the flywheel collet
  16. Slide out the crank shaft, checking bearings along the way.
  17. Clean but don't remove anything, don't touch the edges
  18. Flush your bearings with brake cleaner and two drops of oil
  19. Clean the oxides off the crank and clean out rings and ports.
  20. If removing G clips from piston, do it in a large clear plastic bag. (And you'll still lose them)
  21. Carby's usually only need a rubber boot clean and make sure you have a good seal when you rebuild it.
  22. Careful of head shims, they bend and warp easily.
  23. Hand lube it all and put it back the way you found it.

Marko R1 09-26-2015 11:05 PM
Originally Posted by danyvw (Post 14199428)
Just search YouTube, there are no less than 15 videos of how to rebuild a nitro engine.
That is exactly what I did and only took me 10min to pull it down :)

Marko R1 09-26-2015 11:08 PM
Originally Posted by blis (Post 14199469)
  1. Remove the clutch and leave the flywheel on (You'll need it to remove the liner)
  2. Remove Air cleaner, wash in soapy water and leave to dry
  3. Remove the pullstart if applicable
  4. Clean the engine - including head bolts
  5. WARM UP THE ENGINE with a hair drier so it's hot to touch, not scolding.
  6. Loosen the glow plug
  7. Check the carby is tight, if you want to service the carby, remove it and be mindful of o-rings
  8. Remove the back plate
  9. Remove the head, if separate head, try to turn the flywheel to pop the button.
  10. If you have to pry, pry equally, opposing each one forming a star and use a plastic blade!
  11. Grab a cable tie small enough to fit through exhaust port. Position the head of the cable tie in the cylinder so a small portion of the cable tie is lined up with teh liner and the rest with the piston.
  12. Turn the flywheel, if the liner is free, then it should lift as the piston gently pushes upward. NOTE: I said gently, if the liner is stuck, this isnt going to work.
  13. If the liner is stuck, then I'd add more heat and try again, if that fails, then I take piston up to TDC and pry the liner upwards with a plastic screwdriver of types using the crank for leverage... If that fails, you may have to put the engine block in the over (minus carby) and hope 120c-150c helps
  14. Once you have the liner out, remove the piston by using thumb and index finger at TDC.
  15. Remove the flywheel, if you dont have a puller, put an old clutch screw back into the crank as far as you can go and give the screw a tap with a rigid metal object and it should pop the flywheel collet
  16. Slide out the crank shaft, checking bearings along the way.
  17. Clean but don't remove anything, don't touch the edges
  18. Flush your bearings with brake cleaner and two drops of oil
  19. Clean the oxides off the crank and clean out rings and ports.
  20. If removing G clips from piston, do it in a large clear plastic bag. (And you'll still lose them)
  21. Carby's usually only need a rubber boot clean and make sure you have a good seal when you rebuild it.
  22. Careful of head shims, they bend and warp easily.
  23. Hand lube it all and put it back the way you found it.
This is really useful and there are a few little tricks in here which I like. If I left the flywheel on, the separate head would have been Easy to pop off with engine compression and also removing the liner with a plastic zip tie is another great tip...thank you for sharing :)

thordspeed 09-26-2015 11:17 PM
great tricks indeed.. ive tried a few.. ;)

blis 09-26-2015 11:58 PM
Too easy :)

Do it regularly and your engines will last the test of time.

UrabusDenis 09-27-2015 12:59 PM
How to dissasemble - https://www.youtube.com/watch?v=HgwPgLpsHkM

How to assemble - https://www.youtube.com/watch?v=GJyMkqzDoOA

Enjoy :)

Marko R1 09-27-2015 05:22 PM
Originally Posted by UrabusDenis (Post 14200028)
Thanks for the clips

Marko R1 09-27-2015 05:25 PM
What tool do you use for the below step...the g-clip is tiny?

"If removing G clips from piston, do it in a large clear plastic bag. (And you'll still lose them)"

Marko R1 09-27-2015 05:25 PM
What tool do you use for the below step...the g-clip is tiny?

"If removing G clips from piston, do it in a large clear plastic bag. (And you'll still lose them)"

blis 09-27-2015 07:01 PM
Originally Posted by Marko R1 (Post 14200304)
What tool do you use for the below step...the g-clip is tiny?

"If removing G clips from piston, do it in a large clear plastic bag. (And you'll still lose them)"
Ideally a set of fine point surgical clamps. Otherwise a hobby blade can flip it out or fine point needle nose pliers or tweezers

Good luck, pin goes in one way, and it's not necessary to tear it down for a clean, up to you.

Marko R1 09-27-2015 07:27 PM
Originally Posted by blis (Post 14200427)
Ideally a set of fine point surgical clamps. Otherwise a hobby blade can flip it out or fine point needle nose pliers or tweezers

Good luck, pin goes in one way, and it's not necessary to tear it down for a clean, up to you.
Ok in that case I won't remove the pin. I'd only need to remove it if I replaced the piston In Which I am not.

thordspeed 09-27-2015 08:06 PM
Originally Posted by blis (Post 14200427)
Ideally a set of fine point surgical clamps. Otherwise a hobby blade can flip it out or fine point needle nose pliers or tweezers

Good luck, pin goes in one way, and it's not necessary to tear it down for a clean, up to you.
agreed 110%.. ;) :) wouldnt want that coming loose after rebuild.. :sweat:

blis 09-27-2015 08:17 PM
Originally Posted by Marko R1 (Post 14200458)
Ok in that case I won't remove the pin. I'd only need to remove it if I replaced the piston In Which I am not.
Key reason for tearing own a Nitro engine is to degum the bearings of castor, general clea, lube and give it a once over for good measure.


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