O.S. 12cv engine

[Brady Matthews]

I was digging through my bins of nitro engines and came across a froze up O.S. 12cv engine. It doesn't have a backplate or carb. Does anyone know anything about this motor or what vehicle it could be out of?

 

[CertifiedMike]

I know I have a Kyosho that could use a 12 instead of the 10 thats in it!
It was common in RC10GT's too.

 

[jimdavis577]

Thos os.12 were in just about anything .... and that is the iconic head of the late 90-s early 2000s .....i ran these motors in a NTC3 , I know you could buy just the cyl head itself too as a "upgrade". As far as backplates they had pull starters on them .... they had block off plates for them so you could use a starter box ... and most of them used rotary style carbs .... was a very good running motor back in the day ......

 

[Brady Matthews]

Does anyone know how to take this part off? I don't know if it threads on or is just rusted on

 

[CertifiedMike]

Does anyone know how to take this part off? I don't know if it threads on or is just rusted onView attachment 209765

https://www.amazon.sg/Motor-Pinion-Puller-Remover-Helicopter/dp/B0B8HS1QSY
A set up like this is likely what you need.
I don't know sizes etc. Thats for you to research and find.

 

[jimdavis577]

Does anyone know how to take this part off? I don't know if it threads on or is just rusted onView attachment 209765

i know alot of the clutches for the cars/trucks used a nut to hold the flywheel onto the crank ....... but they are also a tapered crank/ flywheel so it did not take alot of torque to hold it onto the crank.... and if memory serves me correctly i also think they were reverse thread for the crank nut ..... but i could be wrong .... its been atleast 15 yrs for me to touch a nitro motor

 

[CertifiedMike]

@Littlemotor is a nitro-guru. When he is free, I'm sure he'll KNOW how to pop this apart... There will be no "likely". I'm also out of practice with nitro.

 

[Brady Matthews]

i know alot of the clutches for the cars/trucks used a nut to hold the flywheel onto the crank ....... but they are also a tapered crank/ flywheel so it did not take alot of torque to hold it onto the crank.... and if memory serves me correctly i also think they were reverse thread for the crank nut ..... but i could be wrong .... its been atleast 15 yrs for me to touch a nitro motor

The flywheel was on backwards to what I am used to and it doesn't have anything to grab onto either

 

[Brady Matthews]

Thos os.12 were in just about anything .... and that is the iconic head of the late 90-s early 2000s .....i ran these motors in a NTC3 , I know you could buy just the cyl head itself too as a "upgrade". As far as backplates they had pull starters on them .... they had block off plates for them so you could use a starter box ... and most of them used rotary style carbs .... was a very good running motor back in the day ......

I don't see where a pull start would crank the crankshaft. what other ways could it be started?

 

[jimdavis577]

I don't see where a pull start would crank the crankshaft. what other ways could it be started?View attachment 209796

yeh that looks like a bump start version ..... normally for a pull start version there is a little dowl on the crank wrist pin that is just a tad smaller than the wrist pin itself ..... that cogs with the pull starter

 

[Brady Matthews]

yeh that looks like a bump start version ..... normally for a pull start version there is a little dowl on the crank wrist pin that is just a tad smaller than the wrist pin itself ..... that cogs with the pull starter

Is there a way that I can start it without the bump box or changing the crankshaft?

 

[jimdavis577]

Is there a way that I can start it without the bump box or changing the crankshaft?

not that i am aware of ......... either has to have the pin on the crank or a way to spin the crank , like a bump box

 

[TeknoJ]

That has to be a bump start type engine... I am not familiar with that engine so I dont know how to pull that collar off the crank snout. Is that a nut inside of that collar piece? If not then you need like a clutch type tool that would hook that thing and press on the crank while pulling it off the shaft savvy?

 

[Brady Matthews]

That has to be a bump start type engine... I am not familiar with that engine so I dont know how to pull that collar off the crank snout. Is that a nut inside of that collar piece? If not then you need like a clutch type tool that would hook that thing and press on the crank while pulling it off the shaft savvy?

I got it off of there. It was stuck but it was threaded on

 

[Brady Matthews]

I got my 15cv engine running pretty good. Sounds a hell of a lot quieter than my .21