HONDA 125m MOTOR "rebuild" question~~~HELP ME PLEASE!

[trikezilla]

hey guys. about a week ago i posted something saying nearly all the threads were stripped out on my M's spark plug hole. Well its still the same dilema...
I went to take the head off so i can replace (the part that the plug threads into) it, but i couldnt get it off after i removed the header, all the bolts, and disconnected everything. I DID NOT drop the engine from the frame..DO I HAVE TO????? if i dont, why cant i get the dumb thing off? is there anything i have forgot to do??

I guess my main question now is do i have to drop the motor. If i do or dont, i should just be able to unbolt that head and it should slip off right..i hope.

as you can tell this is basically the first motor i am doing alone. :rolleyes: :wondering

[Huffa]

Are you aware you must remove the cam sprocket and move the timing chain out of the way. DO NOT remove the timing chain or let it drop down in.

[1985 200s]

84-85 style or 86-87 style?

[ClayW]

Dito to what huffa said. By the way, those motors are a breeze to drop and reinstall. Easy.

[trikezilla]

It is a 1984. is the timing chain and sproket on top of the motor..kind of towards the front?

[200xman]

It is a 1984. is the timing chain and sproket on top of the motor..kind of towards the front?

If you're asking that question you should stop now and get a manual. It is a bit different than a 2 stroke. :rolleyes:

[Huffa]

If you're asking that question you should stop now and get a manual. It is a bit different than a 2 stroke. :rolleyes:

Absolutly.......don't go tearing into it if you really don't know what your doing!

and to annwer your ?...... Yes, the cam sprocket is torward the front hidden by the cam cover. The valves are all timed in sink with the piston rotation. You MUST have the crank & cam sprocket in the proper postion when reinstalling the chain. One or 2 tooth off and you might bend the valves.
You Must have the motor at top dead center on the compression stroke also!

A manual is the only way!

[trikezilla]

ok...thats what i thought (about the manual. Guess ill have to stop being cheap and pick one up. LOL...if you are reading this, and have one please let me know!!

thanks again,
Charlie

[hondaATCman]

Absolutly.......don't go tearing into it if you really don't know what your doing!

and to annwer your ?...... Yes, the cam sprocket is torward the front hidden by the cam cover. The valves are all timed in sink with the piston rotation. You MUST have the crank & cam sprocket in the proper postion when reinstalling the chain. One or 2 tooth off and you might bend the valves.
You Must have the motor at top dead center on the compression stroke also!


Yes, you are correct except for the last sentence. When timing a motor you do not have to have it at TDC on the compression stroke, just TDC (does not need to be a particular stroke) Technically, there is no such thing as a compression stroke until the head is installed and the motor is in time. ;) However, you do set the motor at TDC on the compression stroke when adjusting the valves (after you have properly set the timing of course). This is the one position where there is no force of any kind on the valves.

P.S. Not trying to be picky or anything...just trying to save some time and aggrevation, especially for a beginner mechanic, by cutting out a step that does not have to be done.

[88 Turbo Coupe]

There is a 85 125m engine for sale on ebay and its pretty cheap

[84250r]

I have a chance to get an 87 125. The motor needs just rings. Send me a pm if you think you would be interested.

[Huffa]

Yes, you are correct except for the last sentence. When timing a motor you do not have to have it at TDC on the compression stroke, just TDC (does not need to be a particular stroke) Technically, there is no such thing as a compression stroke until the head is installed and the motor is in time. ;) However, you do set the motor at TDC on the compression stroke when adjusting the valves (after you have properly set the timing of course). This is the one position where there is no force of any kind on the valves.

P.S. Not trying to be picky or anything...just trying to save some time and aggrevation, especially for a beginner mechanic, by cutting out a step that does not have to be done.


Yep, your correct and it's a good practice for us all to keep an eye out on other comments that may be wrong. Good work!

[hondaATCman]

Yep, your correct and it's a good practice for us all to keep an eye out on other comments that may be wrong.

Yep, you're right again!! :rolleyes: