WR250, How to tell when piston is at Top Dead Centre?

Joined
May 9, 2007
Messages
8
Likes
0
#1
Hi, Just rebuilt the engine in my 01 wr250. I just need to attach the chain to the cams. In the manual it says to line up the hole in the crank case with a groove on the bell thing under the crank case, but there is no groove on it like it shows in the manual. All there is is a marking saying "HI".

Should i line this marking up with the hole in the crank case? If not is there any other way that i can tell when it is at TDC?

Any advice would be great, thanks.
 

CaptainObvious

Formally known as RV6Junkie
Damn Yankees
Joined
Jan 8, 2000
Messages
3,331
Likes
1
#3
With the timing chain removed, each full revolution of the crank puts the piston at TDC. As noted above, the "I" is the timing mark. You can confirm this by keeping your finger (lightly) inserted in the spark plug hole as the pressure will stop and suction will start.
 
Joined
Jan 27, 2000
Messages
6,959
Likes
42
#4
You can also carefully place a long, thin screwdriver down the spark plug hole and feel the top of the piston. Rock the engine back and forth to feel top dead center. Then, look at the timing marks on the flywheel, (bell thing) and see what mark lines up.
 

CaptainObvious

Formally known as RV6Junkie
Damn Yankees
Joined
Jan 8, 2000
Messages
3,331
Likes
1
#5
Ol'89r said:
You can also carefully place a long, thin screwdriver down the spark plug hole and feel the top of the piston.
I was going to suggest that, but then I didn't want to see a thread titled:

How do I remove a small screw driver from my cylinder? :laugh:
 
Joined
Aug 13, 2007
Messages
13
Likes
0
#6
Someone explain to me what the "I" is. There is something that you can look at to see if the Piston is in top position? O_O
 
Joined
Sep 25, 2007
Messages
132
Likes
0
#7
the you have to match up the I on the fly wheel with the groove on the fly wheel cover. that is top dead center, or you could just do the first 2 steps of the starting procedure as that puts it at top dead center.