200s engine question.

[MonkOFox]

Is the 200s motor a "non-interference" motor? I'm going to put it back together. Well make it TDC and all that good stuff. Would easy my mind if there was no chance for the piston to ping the valves.

Thanks.

[captain2207]

I would think it would interfere.what's making you think it would?where in tx are you?

[rg97]

I dont think it does, just because i thought about it like this. During the exhaust stroke, the exhaust valve is fully extended and the piston comes to TDC so that it pushes out the exhaust, then valve closes, intake opens, fuel sucked in, and so on. So, if the exhaust valve is open and the piston is at TDC, and they dont hit, then they will never hit unless something goes really awry. I think thats also the reason that there are valve cuts in the top of the piston.

[kb0nly]

They can interfere and smack the piston if the timing is off! Set your timing by the manual, slowly roll the engine over by hand a few times after assembly is done to ease your mind and then forgettaboutit... LOL

[MonkOFox]

Yeah im definitely going to do it by the manual. Ill just turn it manually to make sure, good advice. Ill be putting the cam, stator and cover on tomorrow, ill post pictures and stuff if i have doubts.

Thanks,

Justin.

[kb0nly]

Best way to do it, by the book, so to speak. After you have done it once i bet you can do it by memory next time.... LOL

[MonkOFox]

Ok so I found the 'T' mark on the flywheel and lined it up with the index mark through that little hole on top of the bottom end.



It's kind of weird though. Right when it gets to the T mark the crank rolls over by itself a little and the T is no longer visible. But the piston is at the top.
Touched it through the spark plug hole with a screw driver.

Another question. Here is the portion of the manual on the cam installation:



However, it never specifies whether or not to attach the cam to the sprocket lobes up or down.

Here is a pic of the sprocket:



The 'O' is supposed to line up with the groove (index mark) on the valve cover.

I'm not sure whether to mount it like this:



or like this:



Any advice would be appreciated.

I also have to buy a oil hole plug (?) I guess.:

[C.J]

Lobes down. If the lobes were up it would push the valves open 180° early,,, plus would be hella hard to bolt together too!! Lol

[MonkOFox]

Awesome, I really appreciate it!

[MonkOFox]

So what is that oil plug for. I mean, I know it plugs that hole but what is it's purpose?

[C.J]

Are you talking about te hole in the cam journal?

[MonkOFox]

I don't think so. The last picture on #7. There is a hole that a little tiny oil hole plug is supposed to go into (on the lip of the cylinder body). Was just wondering why it's there and why it needs to be plugged. I already ordered it was only like ~2 bucks I think.

[oscarmayer]

yes it is an interference motor. that is why if you are 1-2 teeth off the sprocket you will bend valves or break pistons or both.

[MonkOFox]

Thanks for the info oscar.

[kb0nly]

Wow your inspection plug is really buggered up! LOL

It will roll a bit past T without the piston moving because the bottom end of the rod and crank can rotate a bit until the rod is angled the other way and starts to pull it down, think of how it rotates and you will get what i mean by that.

That little rubber plug in my opinion is an inspection plug, because if you pull it out then you can clean the oil galleys in the head, but without it there you can loose oil pressure at that point instead of the oil going through the small hole at the back cam bearing and into the cams center. Definitely needed for correct flow.